Dental Technician, Volume 2

NONRESIDENTTRAININGCOURSE

October 1999

Dental Technician,Volume 2NAVEDTRA 14275

DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited.

Although the words "he," "him," and"his" are used sparingly in this course toenhance communication, they are notintended to be gender driven or to affront ordiscriminate against anyone.

DISTRIBUTION STATEMENT A: Approved for public release; distribution is unlimited.

PREFACE

By enrolling in this self-study course, you have demonstrated a desire to improve yourself and the Navy.Remember, however, this self-study course is only one part of the total Navy training program. Practicalexperience, schools, selected reading, and your desire to succeed are also necessary to successfully roundout a fully meaningful training program.

THE COURSE: This self-study course is organized into subject matter areas, each containing learningobjectives to help you determine what you should learn along with text and illustrations to help youunderstand the information. The subject matter reflects day-to-day requirements and experiences ofpersonnel in the rating or skill area. It also reflects guidance provided by Enlisted Community Managers(ECMs) and other senior personnel, technical references, instructions, etc., and either the occupational ornaval standards, which are listed in the Manual of Navy Enlisted Manpower Personnel Classificationsand Occupational Standards, NAVPERS 18068.

THE QUESTIONS: The questions that appear in this course are designed to help you understand thematerial in the text.

VALUE: In completing this course, you will improve your military and professional knowledge,Importantly, it can also help you study for the Navy-wide advancement in rate examination. If you arestudying and discover a reference in the text to another publication for further information, look it up.

1999 Edition Prepared byDTC(SW) J. Greg Longe and

DTC(SW/AW) Cheral Wintling

Published byNAVAL EDUCATION AND TRAINING

PROFESSIONAL DEVELOPMENTAND TECHNOLOGY CENTER

NAVSUP Logistics Tracking Number0504-LP-026-9060

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Sailor’s Creed

"I am a United States Sailor.

I will support and defend theConstitution of the United States ofAmerica and I will obey the ordersof those appointed over me.

I represent the fighting spirit of theNavy and those who have gonebefore me to defend freedom anddemocracy around the world.

I proudly serve my country’s Navycombat team with honor, courageand commitment.

I am committed to excellence andthe fair treatment of all.”

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CONTENTS

CHAPTER Page

1. Dental Radiology. . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1

2. Dental Examinations . . . . . . . . . . . . . . . . . . . . . . . . . 2-1

3. Preventive Dentistry. . . . . . . . . . . . . . . . . . . . . . . . . 3-1

4. Operative Dentistry. . . . . . . . . . . . . . . . . . . . . . . . . . 4-1

5. Oral Surgery Assistance . . . . . . . . . . . . . . . . . . . . . . . 5-1

6. Periodontic Assistance . . . . . . . . . . . . . . . . . . . . . . . . 6-1

7. Endodontic Assistance . . . . . . . . . . . . . . . . . . . . . . . . 7-1

8. Prosthodontic Assistance . . . . . . . . . . . . . . . . . . . . . . . 8-1

9. Dental Treatment Room Emergencies . . . . . . . . . . . . . . . . 9-1

10. Forensic Dentistry. . . . . . . . . . . . . . . . . . . . . . . . . . 10-1

APPENDIX

I. References Used to Develop This TRAMAN . . . . . . . . . . . AI-1

INDEX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . INDEX-l

The Nonresident Training Course (NRTC) follows the Index

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INSTRUCTIONS FOR TAKING THE COURSE

ASSIGNMENTS assignments. To submit your assignmentanswers via the Internet, go to:

The text pages that you are to study are listed atthe beginning of each assignment. Study thesepages carefully before attempting to answer thequestions. Pay close attention to tables andillustrations and read the learning objectives.The learning objectives state what you should beable to do after studying the material. Answeringthe questions correctly helps you accomplish theobjectives.

http://courses.cnet.navy.mil

SELECTING YOUR ANSWERS

Grading by Mail: When you submit answersheets by mail, send all of your assignments atone time. Do NOT submit individual answersheets for grading. Mail all of your assignmentsin an envelope, which you either provideyourself or obtain from your nearest EducationalServices Officer (ESO). Submit answer sheetsto:

Read each question carefully, then select theBEST answer. You may refer freely to the text.The answers must be the result of your ownwork and decisions. You are prohibited fromreferring to or copying the answers of others andfrom giving answers to anyone else taking thecourse.

COMMANDING OFFICERNETPDTC N3316490 SAUFLEY FIELD ROADPENSACOLA FL 32559-5000

SUBMITTING YOUR ASSIGNMENTS

To have your assignments graded, you must beenrolled in the course with the NonresidentTraining Course Administration Branch at theNaval Education and Training ProfessionalD e v e l o p m e n t a n d T e c h n o l o g y C e n t e r(NETPDTC). Following enrollment, there aretwo ways of having your assignments graded:(1) use the Internet to submit your assignmentsas you complete them, or (2) send all theassignments at one time by mail to NETPDTC.

Answer Sheets: All courses include one“scannable” answer sheet for each assignment.These answer sheets are preprinted with yourSSN, name, assignment number, and coursenumber. Explanations for completing the answersheets are on the answer sheet.

Do not use answer sheet reproductions: Useonly the original answer sheets that weprovide—reproductions will not work with ourscanning equipment and cannot be processed.

Grading on the Internet: Advantages toInternet grading are:

Follow the instructions for marking youranswers on the answer sheet. Be sure that blocks1, 2, and 3 are filled in correctly. Thisinformation is necessary for your course to beproperly processed and for you to receive creditfor your work.

you may submit your answers as soon asyou complete an assignment, andyou get your results faster; usually by thenext working day (approximately 24 hours).

COMPLETION TIME

Courses must be completed within 12 monthsfrom the date of enrollment. This includes timerequired to resubmit failed assignments.

In addition to receiving grade results for eachassignment, you will receive course completionconfirmation once you have completed all the

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PASS/FAIL ASSIGNMENT PROCEDURES

If your overall course score is 3.2 or higher, youwill pass the course and will not be required toresubmit assignments. Once your assignmentshave been graded you will receive coursecompletion confirmation.

If you receive less than a 3.2 on any assignmentand your overall course score is below 3.2, youwill be given the opportunity to resubmit failedassignments. You may resubmit failedassignments only once. Internet students willreceive notification when they have failed anassignment--they may then resubmit failedassignments on the web site. Internet studentsmay view and print results for failedassignments from the web site. Students whosubmit by mail will receive a failing result letterand a new answer sheet for resubmission of eachfailed assignment.

COMPLETION CONFIRMATION

After successfully completing this course, youwill receive a letter of completion.

ERRATA

Errata are used to correct minor errors or deleteobsolete information in a course. Errata mayalso be used to provide instructions to thestudent. If a course has an errata, it will beincluded as the first page(s) after the front cover.Errata for all courses can be accessed andviewed/downloaded at:

http:/ /www.advancement.cnet .navy.mil

STUDENT FEEDBACK QUESTIONS

We value your suggestions, questions, andcriticisms on our courses. If you would like tocommunicate with us regarding this course, weencourage you, if possible, to use e-mail. If youwrite or fax, please use a copy of the StudentComment form that follows this page.

For subject matter questions:

E-mail: [email protected]: Comm: (850) 452-1001, Ext. 2169

DSN: 922-1001, Ext. 2169FAX: (850) 452-1370(Do not fax answer sheets.)

Address: COMMANDING OFFICERNETPDTC (CODE N313)6490 SAUFLEY FIELD ROADPENSACOLA FL 32509-5237

For enrollment, shipping, grading, orcompletion letter questions

E-mail: [email protected]: Toll Free: 877-264-8583

Comm: (850) 452-151/1181/1859DSN: 922-1511/1181/1859FAX: (850) 452-1370(Do not fax answer sheets.)

Address: COMMANDING OFFICERNETPDTC (CODE N331)6490 SAUFLEY FIELD ROADPENSACOLA FL 32559-5000

NAVAL RESERVE RETIREMENT CREDIT

If you are a member of the Naval Reserve, youwill receive retirement points if you areauthorized to receive them under currentdirectives governing retirement of NavalReserve personnel. For Nava l Reserveretirement, this course is evaluated at 9 points.(Refer to Administrative Procedures for NavalReservists on Inactive Duty, BUPERSINST1001.39, for more information about retirementpoints.)

COURSE OBJECTIVES

In completing this nonresident training course,you will demonstrate a knowledge of the subjectmatter by correctly answering questions on thefollowing subjects: dental radiology andexaminations; preventive and operativedentistry; oral surgery, periodontic, endodontic,and prosthodontic assistance; dental treatmentroom emergencies, and forensic dentistry.

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Student Comments

Course Title: Dental Technician, Volume 2

NAVEDTRA: 14275 Date:

We need some information about you:

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Privacy Act Statement: Under authority of Title 5, USC 301, information regarding your military status isrequested in processing your comments and in preparing a reply. This information will not be divulged withoutwritten authorization to anyone other than those within DOD for official use in determining performance.

NETPDTC 1550/41 (Rev 4-00)

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CHAPTER 1

DENTAL RADIOLOGY

INTRODUCTION

The purpose of dental radiography is to recordimages of a patient's oral structures on film by usingX-rays. When the X-ray films are processed, theresulting radiographs provide the dental officer with avaluable diagnostic aid. In the case of death,radiographs can be used to aid in identification asdiscussed in chapter 10, "Forensic Dentistry."

The first section of this chapter covers the basicfundamentals of dental radiography. Included are thephysics and biology of radiography.

Since X-radiation can be harmful, you mustobserve certain safety precautions when using anX-ray machine or working in an area where one isbeing used. These precautions are covered in thesecond part of this chapter.

The major portion of this chapter is devoted toexplaining how to operate a dental X-ray machine,expose intraoral radiographs (radiographs taken insidethe patient’s mouth), process the X-ray films, andmount the finished radiographs.

The last part of this chapter covers the panoramicX-ray machine, which you will use to make extraoralradiographs (radiographs made outside the patient’smouth).

FUNDAMENTALS OF DENTALRADIOLOGY

Oral radiography is the art of recording images of apatient’s oral structures on film by using X-rays(roentgen rays). The rays were recognition ofWilhelm Konrad Roentgen, a scientist, who firstdiscovered X-rays in 1895. While experimenting witha device called a Crookes tube, which generatedcathode rays, he noted that a photographic platecompletely wrapped in black paper and lying near thetube was fogged when developed. He realized thatsome form of invisible ray, able to pass through theblack paper, must be coming from the tube. Later,while in his darkened laboratory, he noticed that afluorescent screen located six feet away was glowing.He knew that the cathode rays could travel only shortdistances outside the cathode tube and realized he was

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observing a new, unknown ray, which he called anX-ray because the symbol "X" is used for theunknown in mathematics.

The first dental radiograph was taken the sameyear by Dr. Otto Walkoff. Within 10 years,radiographs were being used for diagnosis of medicaland dental conditions, for X-ray therapy, and- forscientific studies. Although technology over the yearshas made tremendous improvements in X-rayequipment, the basic concepts are the same.

Like visible light rays, X-rays are electromagneticrays that travel in a wave motion. The measurement ofthis wave motion is called a wavelength. The basicdifference between X-rays and other electromagneticrays is in their wavelength. X-rays have an extremelyshort wavelength, which enables them to penetratematter that usually absorbs or reflects light or otherelectromagnetic rays with longer wave-lengths.

Although X-rays share the properties of otherelectromagnetic rays, their action is considerablydifferent. Some of the characteristics and properties ofX-rays are:

They travel in straight lines at the speed of light.

They affect photographic film by producing ahidden image made visible by processing.

They cause certain substances to fluoresce

(glow).

They cause irritation of living cells and, in largeamounts, can cause necrosis (death) of the cells,a fact that necessitates caution in using X-rays.

X-rays are produced when a metal (tungsten)target is bombarded by a stream of electrons. TheX-rays are emitted in the tubehead and directed by thetubehead cone through the subject, producing animage on the film.

The density of the X-ray image is controlled byfour factors: kilovoltage (kVp), exposure time,milliamperage (mA), and target-film distance (TFD).All of these factors are interrelated and may be variedby the operator. The procedures for setting thesefactors will be discussed later.

RADIATION SAFETY

Proper safety precautions must be observed by allpersons working in or near an area where X-rays arebeing generated. X-rays can be dangerous. Long termoverexposure to radiation may result in loss of hair,redness and inflammation of the skin, blood countchange, cell atrophy (wasting away), ulcerations,sterility, genetic damage, cancer, leukemia, and death.

There are safety measures designed to protect thepatient and the health care team from the dangers ofoverexposure to radiation and the operation of X-rayequipment. You must observe these safety measureswhen working in radiology. Your command will haveinstructions and standard operating procedures (SOP)for the operation of dental radiographic (X-ray) unitsand equipment. You will be required to read theseprocedures if you are newly assigned to the radiologydepartment. There are other numerous responsibilitiesthat include providing radiology support for oraldiagnosis, log maintenance, infection control, testingfor quality control, and processor maintenance.

PATIENT PROTECTION

A number of precautions are taken to prevent thepatient from being exposed to inappropriate diagnosticradiation. The decision to order dental radiographs isdetermined by the dental officer on a case by case basisfor each patient. Only a dental officer is authorized toorder and diagnostically interpret dental radiographs.

Perhaps the most important safety measure is theresponsibility of the assistant: When takingradiographs, you should always have patients wearlead aprons and thyroid collars to shield theirreproductive organs and thyroid glands. There isonly one exception to this rule; when obtaining apanorex radiograph, the thyroid collar is not usedsince it blocks part of the X-ray beam. In addition,always ask a female patient whether or not she ispregnant or if pregnancy is questionable, before takingradiographs. If she is pregnant, consult the dentalofficer.

Other radiation safety measures include X-raymachines that have built-in safeguards that filter outharmful radiation and restrict the central X-ray to thesmallest possible area. Fast film is used to shortenexpos ure time; and only essential radiographs aretaken on patients.

Figure 1-1.—Environmental dosimetry radiation film badge.

ASSISTANT PROTECTION

When you work near a source of radiation, yourX-ray department will be issued an environmentaldosimetry radiation film badge (fig. 1-1).

feet from the tube head and never in the direct line ofradiation during expos ure. These film badges

Appropriately placed environmental f i lmbadges are used to monitor stray radiation that mayoccur in and around the X-ray department. Thebadges are placed in the X-ray room behind thetechnicians protective lead-lined barrier or at least 6

contain X-ray sensitive film in a light-tight packet.The film packets are collected every 6 to 7 weeks.After collection, the film is sent to the radiationdetection laboratory for processing and evaluation.Any abnormally high readings (i.e., greater than0.010 REM [Radiological Equivalent Mammel])shall be referred to the Radiation Health Office forinvestigation.

When you take radiographs on a patient, observethe following precautions to avoid unnecessaryexposure to radiation:

NEVER stand in the path of the central X-raybeam during exposure.

NEVER hold the X-ray film packet in thepatient's mouth during exposure.

NEVER hold the tube head or the tube headcylinder of the X-ray machine during exposure.

ALWAYS stand behind a lead-lined screenduring an exposure.

X-RAY FILM LOG

Another portion of radiation safety is to accountfor all radiographs that are taken. An X-ray film log

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shall be maintained in all X-ray rooms and will containthe following information:

Column 1: Patient's Name

Column 2: Patient's SSN

Column 3: Patient's Unit

Column 4: Rank/Rate/Retired/Dependent/etc.

Column 5: Number of X-ray exposures andtype: bitewing, periapical, occlusal,panograph

Column 6: kVp, mA, exposure time

Column 7: Reason retake X-ray required (ifapplicable)

When stating the reason for a retake X-ray, bespecific on the nature of the retake, for example:conecut, elongated, foreshortened, dark image, etc.

DENTAL X-RAY MACHINES

The most commonly used X-ray machine is thewall-mounted dental X-ray unit (fig. 1-2). Because the

basic components and operating techniques of alldental X-ray machines are similar, we will only discussthe wall-mounted unit. The component parts of thewall-mounted machine discussed here are the tubehead, cylinder, extension arm, ready light, and aseparate control panel.

TUBE HEAD

The tube head (fig. 1-3) contains the X-ray tubeand other components necessary for generating X-rays.When an exposure is made, X-rays pass through analuminum filter that screens out unnecessary radiation.Angulation scales are on both sides of the tube head forprecise positioning technique.

CYLINDER

The cylinder (or cone) is affixed to the tube headand is used to align the tube head with the patient andthe X-ray film. It is open-ended and composed of leadlaminated material that establishes the minimumdistance from the X-ray source to the patient’s skin.

Figure 1-2.—Wall-mounted X-ray machine.

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Figure 1-3.—Tube head and cylinder (short cone).

The X-ray beam passes from the aluminum filterthrough an opening in a lead diaphragm, whichrestricts the beam to 2.6 inches at the cylinder tip.There are two commonly used cylinder lengths. A tubehead with an X-ray source to cylinder end distance of 8inches is referred to as a "short cone" machine, while atube head with an X-ray source to cylinder end distanceof 16 inches is referred to as a "long cone" machine. Itis essential that the technician knows the X-ray sourceto cylinder end distance in order to set the appropriateexposure settings.

The tube head is attached to an extension arm. Theextension arm is movable, allowing you to adjust theposition of the tube head for each patient.

CONTROL PANEL

The operational controls on the control panel arecovered in the discussion on the operational check.

OPERATIONAL CHECK (WITHOUTPATIENT)

At the beginning of each workday, you shouldactivate the X-ray machine to ensure that it is workingproperly. This operational check is conducted without

a patient in the chair. In order to check the machine,you must be thoroughly familiar with its operation.Read the manufacturer's instructions carefully.

Throughout this discussion of the operationalcheck, refer to figure 1-4. The steps of procedure are:

1. Energize the control panel. The control panelshown in figure 1-4 has three push buttons in the upperleft corner. By depressing either the 10 mA or the 15 mApushbutton, you will energize the machine and selectthe milliampere setting at the same time. Once thebutton is depressed the "power on" light will glowamber, indicating that the system is turned on. (A settingof 10 mA is normally used for intraoral radiographs.)

NOTE: Some machines have separate masteron/off switches. On these machines, you should FIRSTactivate the master switch, and then select themilliamperes (10 mA or 15 mA) setting. A 10 mAsetting is used for most dental radiographs. Some unitsuse a combination master on/off switch and mAselector to energize the machine.

2. Set the tube head selector. On units withmultiple tube head capabilities, depress the pushbuttonthat corresponds to the tube head to be used, normally

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Figure 1-4.—Control panel for wall mounted X-ray machine.

tube 1. The depressed button and a lamp on the selectedtube head will glow.

3. Select the kilovoltage. Adjust the kilovoltage(kV) until the desired kilovolt peak (kVp) is registeredon the kilovolt meter. The kVp setting will vary,depending on the patient's bonesize and density;specific settings will be given later in this chapter.

NOTE: Some X-ray mach ines shu t o f fautomatically if the setting exceeds 90 kVp. Refer tothe manufacturer 's instruct ions for reset t ingprocedures.

4. Set the exposure time. Check the X-ray filmmanufacturer’s recommended time setting for the typeof film being used, the kVp and mA settings, and thefilm focal distance (FFD). The time settings may be infractions of a second or impulses. An impulse equals1/60 of a second. To protect the patient from needlessexposure to radiation, use the minimum exposure timenecessary to produce the desired results.

5. Check to see that the machine is emittingX-rays. Place an unexposed packet of X-ray film on theseat of the dental chair. Put a penny on top of the filmpacket and position the tube head. The tube headcylinder should be pointed down, 6 inches above andcentered on the penny. When the tube head is correctlypositioned, prepare to make the exposure.

WARNING: You must be behind a lead-linedshield or at least 6 feet from the tube head when makingthe exposure.

6. Make the exposure by depressing the exposurebutton located on the control panel. Exposure start isdelayed approximately 1/2 second. If the machine isworking correctly, you will hear a click and the tonesignal, and the "X-ray" lamp on the control panel willglow. This indicates that an exposure is being made. Donot release the exposure switch until the selectedexposure time is completed.

7. After making the exposure, process the X-rayfilm. If the processed film shows a light area where thepenny was, the X-ray machine is working properly.Processing techniques will be discussed later in thischapter.

MACHINE OPERATION (WITHA PATIENT)

Once the X-ray machine's operational readinesscheck has been completed, it is a simple matter toprepare it to take radiographs on a patient. Set the mAselector, the tube head selector (if necessary), the kVpselector, and the exposure time. Before you make theexposure, position the patient, the film packet, and thetube head cylinder. These patient positioningprocedures are discussed later.

SECURING THE X-RAY MACHINE

At the end of each work day, deactivate the offswitch and secure the machine (e.g., the tube headextension arm should be completely folded tominimize the weight of the tube head on the arm andwall mounting plate).

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USER MAINTENANCE

An X-ray machine is very expensive. Doeverything possible to keep it in good working order byfollowing the user maintenance procedures containedin the manufacturer's instructions.

General user maintenance includes dusting theX-ray machine daily, and removing blood and debrisfrom all surfaces using a cloth moistened withdetergent solution. Follow disinfection proceduresdiscussed later in the chapter.

NOTE: DO NOT use a wet cloth; moisture mightenter the control panel causing an electrical shortcircuit that could cause severe damage to the machineand possible harm to the operator. DO NOT usecleaners or solvents.

Never attempt to repair the X-ray machineyourself. If it breaks down, report it to your supervisor.All repairs are the responsibility of the dentalequipment repair technician.

INTRAORAL RADIOGRAPHS

Intraoral radiographs are made with the X-ray filmplaced inside the patient’s mouth. There are three typesof intraoral radiographic examinations: periapicalexamination, interproximal (bitewing), and theocclusal.

To ensure diagnostic quality radiographs, you mustproperly align the X-ray film, the area to be X-rayed,and the tube head cylinder of the X-ray machine.Alignment can be accomplished by using either theparallel film placement technique (preferred method)or the bisecting angle technique. The followingdiscussion provides detailed information on how totake periapical and interproximal (bitewing)radiographs, using both techniques. For the occlusalexamination, you will use only the bisecting angletechnique.

INTRAORAL FILM

The X-ray films used for intraoral examinationsdiffer in size, depending on the type of examination.Figure 1-5 compares the sizes of periapical,interproximal (bitewing), and occlusal film.

There are different speeds of film. The mostcommonly used is an ultraspeed film known as D speedfilm. Ektaspeed (or E speed) film requires lessradiation per exposure than D speed film. Somecommands are now using E speed film. The exposure

Figure 1-5.—Intraoral X-ray film.

times given in the following sections are for D speedfilm.

Intraoral film comes in film packets, with alightproof and waterproof outer wrapper. Inside thewrapper, the film is sandwiched between blackprotective paper and backed with lead foil. Figure 1-6shows a partially unwrapped periapical film.

STORAGE

Intraoral film can be ordered through normalsupply channels. It must be stored in a cool, dry area. Invery hot or damp climates, the film should berefrigerated. Never store it near steam lines orradiators, and never store it near film processing

Figure 1-6.—Partially unwrapped periapical film.

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solutions, since the escaping fumes could damage thefilm.

Because the unprocessed film is sensitive to X-rays,it must be stored in lead lined containers, as shown infigure 1-7 in the open and closed position. Removeonly one film at a time from the lead film dispenser,make the exposure, and place the film in a clean papercup or disposable container. Place the cup ordisposable container in a lead container or behind aprotective screen before making the next exposure.Repeat this procedure for each exposure. Maintain aminimum stock of film, and use the oldest film first sothe stock is always fresh.

PRECIOUS METALS RECOVERYPROGRAM (PMRP)

The precious metals recovery program isdesignated to save Department of Defense (DOD)money by recycling precious metals and using thosefunds to offset the cost of supplies for DOD activities.Both silver and lead are precious metals that are found

in the X-ray department. The silver is found in usedfixer solutions and on dental films. The lead is found inX-ray packets. These precious metals should be savedand turned into the supply department following theguidelines in BUMEDINST 4010.3, "Precious MetalsRecovery Program."

ASSISTANT PREPARATION

To protect yourself and the patient from diseases,perform the handwashing and gloving procedurescovered in Dental Technician, Volume 1, chapter 9,"Infection Control ."

PATIENT PREPARATION

To properly prepare a patient for an X-rayprocedure, you should employ the followingtechniques:

Ensure all infection control procedures arefollowed.

Figure 1-7.—Lead lined container.

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Seat and position the patient. Positioning variesaccording to the type of radiographic examination andthe film placement technique you are going to use.Specific positioning procedures will be discussed later.

If the patient is a woman, ask her if she ispregnant. If she is or you suspect that she might be,consult the dentist.

Ask the patient to remove eyeglasses, completedentures, removable partial dentures, earrings, or anyother objects about the head and neck.

Explain the X-ray procedures to the patient. Ifthe patient is nervous about being X-rayed, explain thesafety precautions taken to prevent overexposure toradiation.

Drape the patient with a lead apron andthyroid collar.

Quickly examine the patient's mouth todetermine its anatomy. Such things as a small mouth, anabnormally shallow vault, crooked teeth, and bonyprotrusions can affect the placement of the film packet.The patient's overall bone size and density willdetermine the kVp setting. For a patient with a normalbone size and density, use a kVp setting of 87; for apatient with a thick bone size and density, use a 90 kVpsetting.

Position the patient's head securely against theheadrest.

Place the film packet in the patient's mouth. Filmplacement procedures will be discussed later.Occasionally patients may gag when the film is placedin their mouth. The gagging reflex may be caused bynervousness, so remain calm and reassure the patient.You might recommend that patients breathe throughtheir nose, since it is difficult to gag while doing so,having patients rinse out their mouth with cold watermay also help or have patients concentrate onsomething other than gagging. Whatever technique youuse you will have to be swift in placing the film andmaking the exposure because the chance of keeping thegag reflex from returning for an extended period ishighly unlikely.

After the X-ray procedure is completed, youmust store the lead apron and thyroid collar properly toavoid damage as shown in figure 1-8.

PERIAPICAL EXAMINATION

A periapical examination is conducted to obtainradiographs of the crowns, roots, and supporting

Figure 1-8.—Properly stored lead apron with thyroid collar.

structures of the teeth. Figure 1-9 shows a typicalperiapical radiograph.

There are two techniques available to takeperiapical radiographs: paralleling and bisecting-angle. Both techniques use the long axis of the tooth asa focal point. The paralleling technique is the preferredmethod and the bisecting-angle technique is used as analternative. Film placement and techniques arediscussed in the following sections.

PARALLELING TECHNIQUE

When using the paralleling technique, you mustcenter the X-ray film packet behind, and parallel with

Figure 1-9.-Typical periapical radiograph.

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the long axis of the tooth being X-rayed. A tube headwith a 16-inch X-ray source to cylinder end distance(long cone) should be used with the parallelingtechnique. The tube head must be positioned so that thecentral X-ray beam is projected perpendicular to thetooth and the film packet. To properly position the filmand the tube head, use paralleling devices.

There are two different paralleling devices. One isused for radiographs of the anterior teeth; the other isused for radiographs of the posterior teeth. Eachparalleling device consists of a bite-block, an indicatorrod, and locator ring (fig. 1-10). The bite-block has aslot and a film backing support to hold the X-ray filmpacket.

Assembling The Anterior Device

Figure 1-11 shows a fully assembled anteriorparalleling device. Refer to this figure during thefollowing explanation on assembling the parallelingdevice:

Grasp the periapical film packet between thethumb and first two fingers of your right hand. Theprinted surface of the packet should be facing you, andthe side with the raised dot should be in the filmpositioning slot of the paralleling device.

Figure 1-11.—Assembled anterior paralleling device.

Hold the base of the anterior bite-block betweenthe thumb and first two fingers of your left hand. Ensurethat the plastic film support is pointed upward and thefilm positioning slot is away from you.

Holding the film packet in position, press itagainst the plastic support and slide the film down intothe positioning slot. The printed side of the packetshould be facing the plastic support, and the raised dotshould be located toward the positioning slot.

The two prongs of the indicator rod are insertedinto the openings in the bite-block.

Slide the anterior locator ring onto the indicatorrod. Look through the locator ring. If the bite-block and

Figure 1-10.—Anterior and posterior paralleling devices.

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film are centered in the locator ring, the device isproperly assembled and ready for positioning in thepatient’s mouth.

Assembling The Posterior Device

Figure 1-12 shows a fully assembled posteriorparalleling device. Refer to this figure during thefollowing discussion.

Insert the film into the posterior bite-block aspreviously discussed.

NOTE: The posterior device shown in figure 1-11is used for film placement in the right maxillary andleft mandibular quadrants. You must reassemble thedevice, rotating the locator ring and the bite-block,before using it in the left maxillary or right mandibularquadrants. Only the posterior device must bereassembled in this manner, the anterior device doesnot require reassembly.

Placing The Device

remedies discussed earlier.

Once you have assembled the posterior parallelingdevice, place it in the patient's mouth. Be very carefulnot to injure the oral tissue. If the patient gags, use the

Guide the bite-block and the film packet intoposition, centering the packet behind the area being X-rayed. The film packet should be positioned far enoughbehind the tooth so it will be parallel to the long axis ofthe tooth.

After positioning the film packet, slide the locatorring down the indicator rod until the ring almosttouches the surface of the patient's face. Then, positionthe tube head cylinder. The end of the cylinder shouldbe parallel with the locator-ring, and its side should beparallel with the indicator rod.

Once these procedures have been accomplished,the film packet and the tube head are in properalignment. You are now ready to expose the film.

Figure 1-12 .—Assembled posterior parallelling device.

EXPOSURE ROUTINE FOR FULL MOUTHPERIAPICAL EXAMINATION

The full mouth periapical examination consists of14 periapical radiographs (7 maxillary and 7mandibular). The series includes the following filmsand sequence starting with the maxillary arch andproceeding to the mandibular arch:

1. Incisor area

2. Left cuspid area

3. Left bicuspid area

4. Left molar area

5. Right cuspid area

6. Right bicuspid area

7. Right molar area

GUIDELINES FOR TAKING PERIAPICALRADIOGRAPHS, PARALLELINGTECHNIQUE

The following guidelines apply if you are takingeither a full mouth series, or an individual periapicalradiograph. For training purposes, infection controlbarriers are not used in the photographs in this section.

In most cases, the X-ray machine is set at 10 mAfor dental radiographs. The kVp may vary, dependingupon the thickness or the region being radiographed. Ifthe area being radiographed is edentulous (no teethpresent), reduce the recommended kVp by 5. Whenyou are taking radiographs on a child, reduce therecommended kVp to 70. Always consult the dentistbefore taking radiographs on a child. Because of thedifferent types of X-ray equipment in use, the exposuretime selector you use may not have the settingssuggested. Consult the f i lm manufacturer 'sinstructions regarding the desired time setting to use.

Before you perform an individual radiograph or afull mouth periapical examination, prepare the patient,using the procedures explained earlier. When you areusing the parallel film placement technique, theposition of the patient's head is not critical. But, it isbest to adjust the head rest on the dental chair so thatthe patient's "plane of occlusion" is parallel with thefloor and the "midsagittal plane" is perpendicular tothe floor (fig. 1-13.)

It is important to properly position the parallelingdevices and the tube head cylinder when using theparalleling placement technique.

1-10

Figure 1-13.—Midsagittal and occlusal planes.

When taking a full mouth series or an individual

periapical radiograph, follow the given guidelines for

the specific area listed:

NOTE: After each exposure, put the exposed film

in a clean paper cup or disposable container. Then

place the cup or disposable container in a lead

container or behind a protective screen.

1.

2.

3.

4 .

5 .

6.

1.

2.

3.

4.

Maxillary Incisor Area

Set the exposure time selector to manufacturer'ssuggested impulses.

Prepare the anterior paralleling device.

Position the paralleling device with film in thepatient's mouth. Center the film on the midlineso that it is parallel with the long axis of theincisors (fig. 1-14).

Place a cotton roll under the bite-block. Havethe patient close gently but firmly.

Adjust the locator ring and align the tubeheadcylinder as previously described.

Make the exposure.

Maxillary Cuspid Area

Set the exposure time selector to manufacturer'ssuggested impulses.


Position the paralleling device with film in thepatient's mouth. Center the film on the cuspidand parallel with the tooth's long axis (fig. 1-15).

Place a cotton roll under the bite-block and havethe patient close.

1-11

5.

6.

1.

2.

3.

4.

5.

6.

1.

2.

3.

4.

5.

6.

1.

2.

3.

4.

5.

6.

Adjust the locator ring and align the tubeheadcylinder.

Make the exposure.

Maxillary Bicuspid Area

Set the exposure t ime selector to themanufacturer's suggested impulses.

Prepare the posterior paralleling device.

Position the paralleling device with film in thepatient’s mouth. Center the second bicuspid andparallel with the tooth's long axis (fig. 1-16).



Make the exposure.

Maxillary Molar Area

Set the exposure t ime selector to themanufacturer's suggested impulses

Prepare the posterior paralleling device.

Position the paralleling device with film in thepatient's mouth. Center the film on the secondmolar, so the anterior edge of the film includesat least the distal half of the second bicuspid.The film should be parallel with the long axis ofthe molars (fig. 1-17).



Make the exposure.

Mandibular Incisor Area

Set the exposure time selector to the manu-facturer's suggested impulses.


Position the paralleling device with film in thepatient's mouth. Position the film packet so thatit is centered on the midline and parallel with thelong axis of the incisors (fig. 1-18).

Place a cotton roll on the upper surface of thebite-block and have the patient close.


Make the exposure.

Figure 1-14.—Film and cylinder placement: maxillary incisor area.

Mandibular Cuspid Area 3. Position the paralleling device with film in the

1. Set the exposure t ime selector to themanufacturer's suggested impulses.

2. Assemble the anterior paralleling device.

patient's mouth. Center the film on the cuspidand parallel with its long axis (fig. 1-19).

4. Place a cotton roll on the upper surface of thebite-block and have the patient close.

1-12

Figure 1-15.—Film and cylinder placement: maxillary cuspid area.

5. Adjust the locator ring and align the tubeheadcylinder.

6. Make the exposure.

Mandibular Bicuspid Area

1. Set the exposure time to the manufacturer'ssuggested impulses.

2. Assemble the posterior paralleling device.

3. Position the paralleling device with film inthe patient's mouth. Position the film packet so thatit is centered on the second bicuspid and parallelwith its long axis (fig. 1-20).




Mandibular Molar Area

1. Set the exposure time to the manufacturer'ssuggested impulses.

2. Assemble the posterior paralleling device.

3. Position the paralleling device with film in thepatient’s mouth. Position the film packet. Center thefilm on the second molars, so the anterior edge of thefilm includes at least the distal half of the secondbicuspid. The film should be parallel with the longaxis of the molars (fig. 1-21).



1-13

Figure 1-16.—Film and cylinder placement: maxillary bicuspid area.

6. Make the exposure.6. Make the exposure.

VARIATION TO THE EXPOSUREFACTORS AND FILM ALIGNMENT

Some variations to the exposure factors and filmalignment may be necessary for a specific area of thepatient's anatomy.

The dentist may request a radiograph of animpacted third molar. If so, you would prepare theparalleling device in the usual manner, placing the filmfilmpacket off center in the backing support so the filmextends posteriorly to cover the entire third molar area.When you place the paralleling device in the patient'smouth, position it so the anterior edge of the filmincludes the distal half of the first molar.

Use special film placement procedures when apatient has a low palatal vault or edentulous arches.Place one cotton roll on each side of the bite-block asshown in figure 1-22. This ensures that the X-ray filmwill be parallel with the long axis of the teeth beingradiographed.

BISECTING-ANGLE TECHNIQUE

Use the bisect ing-angle technique whenparalleling devices are not available; or when apatient finds it painful or impossible to close on thebite-block; or when an X-ray is needed when a rubberdam is in place. This technique incorporates the use ofa tube head with an X-ray source to cylinder end

1 - 1 4

Figure 1-17.—Film and cylinder placement: maxillary molar area.

distance of 8 inches (short cone). The bisecting-angletechnique is not recommended for routine use.

Since paralleling devices are not used with thebisecting-angle technique, you must pay specialattention to positioning the patient, the film packet, andthe tube head.

Positioning the Patient

For all maxillary periapical radiographs, positionthe patient's head as shown in figure 1-23 from the alaof the nose (the outer portion of the nostril) to thetragus of the ear (a projection of the cartilage on thefront center of the ear). This ala-tragus line should beparallel with the floor. The patient's head should also

be positioned so that the midsagittal plane isperpendicular to the floor.

For mandibular periapical radiographs, lower theheadrest so the patient's head is positioned as shown infigure 1-24. The figure shows a line running from thecorner of the patient's mouth to the tragus of the ear.This line should be parallel with the floor. Again, themid-sagittal plane is perpendicular to the floor.

Positioning the Film

Once the patient is positioned, insert the filmpacket in the patient's mouth with a pair of hemostatsor other holding device. Never slide the packet in; thismight irritate the oral mucosa or cause the patient togag. Gently direct the holding device to the desired

1-15

Figure 1-18.—Film and cylinder placement: mandibular incisor area.

position. In order to adapt the packet to the area being Center the packet behind the tooth to beradiographed and to relieve patient discomfort, it may radiographed. The printed side of the packet shouldbe necessary to shape the packet. Do this by gently face away from the tooth, with the printed dot towardflexing the corners of the packet and holding it over the the occlusal surface. The film is held as close to theend of your thumb. Do not crease the packet. tooth as possible. At this point the long axis of the tooth

1-16

Figure 1-19.—Film and cylinder placement: mandibular cuspid area.

and the plane of the film should be nearly parallel. In patient gently holds the device with the hand from theorder to project the proper image of the tooth onto thefilm, you must visualize an imaginary line bisectingthe long axis of the tooth and the plane of the dentalfilm (fig. 1-25). The central ray is then directedperpendicular (a 90° angle) to the bisecting line. Thiswill project the proper dimensions of the tooth onto thefilm without elongation or foreshortening. If theanterior curvature of the patient's arch is narrow, inserta cotton roll between the packet and the teeth. Thisprevents the film from bending excessively andproducing a distorted image.

Once the film packet is properly positioned, guidea free hand of the patient to the holding device. The

opposite side of the arch being radiographed.

WARNING: The assistant should never hold thefilm packet in position during an exposure.

Each time you take radiographs, use the standardfi lm posi t ions. This helps when comparingradiographs made at different times.

Positioning the Tube Head

After the film is inserted in the patient's mouth,position the tube head so the end of the cylinder is nearthe area to be radiographed. Then, position the tubehead for correct vertical and horizontal angulation

1-17

Figure 1-20.—Film and cylinder placement: mandibular bicuspid area.

using anatomical landmarks on the patient's face. Tellyour patient to maintain the position of the placementof the dental film and not to move while you expose theradiograph.

VERTICAL ANGULATION.—This is theup-and-down positioning of the tube head. A 0°vertical angulation indicates that the tube head ispositioned with the cylinder parallel with the floor (fig.1-26). Angling the tube head so the cylinder pointsupward from 0° will give you a minus (–) degree ofvertical angulation. Angling the tube head so thecylinder points downward from 0° will give you a plus(+) degree of vertical angulation.

Different areas of the mouth require differentdegrees of vertical angulation. The correct verticalangulation can usually be obtained by using the anglesshown on the chart in figure 1-26. Notice the tube headis angled downward for maxillary radiographs, andusually angled upward for mandibular radiographs.The tube head may be horizontal (0°) when X-rayingmandibular molars.

A wrong angulation results in a distortedradiograph. Too little vertical angulation elongates theradiographic image (fig. 1-27); too much verticalangulation foreshortens the image (fig. 1-28).

A standard vertical angulation cannot be used forall patients because of differences in their oral

1-18

Figure 1-21.—Film and cylinder placement: mandibular molar area.

Figure 1-22.—Film and cylinder placement: patients with lowpalatal vaults or edentulous arches.

you to determine when to alter standard verticalangulation to suit the needs of a particular patient.

After you have determined the correct verticalangulation for the area to be radiographed, adjust thetube head using the angle dial on the tube head as areference.

structures. A patient may have an unusually highmaxillary vault or an unusually deep palatal vault. Ineither case, you would decrease the standard verticalangulation by about 5°. On the other hand, for a patientwith an unusually shallow vault, you would increasethe angulation by about 5°. The more experienced youbecome in X-ray techniques, the easier it will be for

1-19

Figure 1-23.—Ala-tragus line parallel with the floor.

Figure 1-24.—Line from the corner of the mouth to the tragus parallel with the floor.

When the tube head has been set for the propervertical angulation, center the tube head cylinder onthe area to be radiographed. The cylinder shouldalmost touch the surface of the patient's skin. Then,position the tube head for correct horizontalangulation.

HORIZONTAL ANGULATION.—This is theside-to-side positioning of the tube head. Position the

tube head so the central X-ray beam is directed straightth rough the embrasures o f the t ee th be ingradiographed. If the horizontal angulation is faulty, thecentral ray will be directed at an angle to theembrasures. This will produce a faulty radiograph,with the images of the teeth overlapping one another.Figure 1-29 illustrates the correct and incorrectcylinder direction.

1-20

Figure 1-25.—Relationship of central ray, tooth, and filmpacket in bisecting-angle technique.

GUIDELINES FOR TAKING PERIAPICALRADIOGRAPHS, BISECTING-ANGLETECHNIQUE

Take the same 14 radiographs using the sameexposure sequence as that discussed for the parallelingtechnique. Complete the following steps:

1. Program the X-ray machine for the discussed

mA and kVp settings. The exposure time varies, just asit did with the paralleling technique. Refer to the film

Maxillary Mandibular

IncisorCuspidBicuspidMolar

+40 to +45+45 to +50+30 to +35+20 to +25

Incisor -15 to -20Cuspid -20 to -25Bicuspid -10 to -15Molar -5 to 0

DTV2F126

Figure 1-26.—Average vertical angulation.

Figure 1-27.—Elongated image.

Figure 1-28.—Foreshortened image.

Figure 1-29.—Correct and incorrect cylinder direction.

manufacturer's instructions for correct time/impulsesettings. Remember to reduce the kVp by 5 when takingradiographs in edentulous areas, and to 70 when takingradiographs on children.

1-21

2. Position the patient as shown in figure 1-23 formaxillary radiographs or figure 1-24 for mandibularradiographs. Remember that the patient's midsagittalplane must be perpendicular to the floor.

3. Position the film packet in the patient's mouth.Have the patient hold the film packet in place with a pairof hemostats or other holding device.

4. Set the vertical angulation of the tube headaccord ing to the chart in figure 1-26.

5. Center the tube head cylinder on the area to beradiographed. To simplify this process, the numberedanatomical landmarks are provided in figure 1-30. Takeradiographs of the area by centering the tube headcylinder on these landmarks:

Mandibular cuspid area: Landmark 6, directlybelow landmark 2 1/4 inches above the lowerborder of the mandible.

Mandibular incisor area: Landmark 5, the tipof the chin.

Maxillary molar area: Landmark 4, below theouter angle of the eye and below thezygomatic bone.

Maxillary bicuspid area: Landmark 3, belowthe pupil of the eye.

Maxillary cuspid area: Landmark 2, besidethe ala of the nose.

Maxillary incisor area: Landmark 1, the tip ofthe nose.

Figure 1-30.—Cylinder positioning landmarks for periapicalradiographs.

Mandibular bicuspid area: Landmark 7,directly below landmark 3 1/4 inches abovethe lower border of the mandible.

Mandibular molar area: Landmark 8, directlybelow landmark 4 1/4 inches above the lowerborder of the mandible.

6. When you have the tube head cylinder centeredon the horizontal landmark, double check to make surethat you have the correct horizontal angulation. Thecentral X-ray beam should be projected straight throughembrasures of the teeth to be radiographed.


8. Remove the film packet from the patient'smouth and place it in a clean paper cup. Place thedisposable container in a lead container or behind aprotective screen before making the next exposure.

INTERPROXIMAL (BITEWING)EXAMINATION

The interproximal examination reveals thepresence of interproximal caries, certain pulpconditions, overhanging restorations, improperlyfitting crowns, recurrent caries beneath restorations,and resorption of the alveolar bone.

A typical interproximal radiograph (fig. 1-31)records in a single exposure the coronal and cervicalportions of both maxillary and mandibular teeth, alongwith the alveolar bone of the region.

Bitewing X-ray film packets are used for theinterpromixal examination. The bitewing film packet(fig. 1-32) has a paper tab, or wing, that the patientbites on to hold the packet in place during the exposure(thus the name bitewing).

Interpromixal radiographs can be made usingeither the paralleling technique or the bisecting angletechnique.

Figure 1-31.—Typical interproximal (bitewing) radiograph.

1-22

Figure 1-32.—Bitewing film packet.

PARALLEL PLACEMENT TECHNIQUE

The following procedures describe this technique:

1. Program the X-ray machine for the discussedtime, mA settings, and kVp settings.

2. Prepare the inter-proximal paralleling device(fig. 1-33). Fold the bitewing tab against the film packetand insert the packet into the bite-block so that theprinted side faces the backing support. Insert the end ofthe indicator rod into the holes in the bite-block. Slidethe locator ring onto the indicator rod. Look through thelocator ring to see if the bite-block is centered in thering. If it is, the paralleling device is ready forpositioning in the patient's mouth.

3. Position the paralleling device with film in thepatient’s mouth so that the anterior edge of the filmtouches the distal surface of the mandibular cuspid (fig.1-34). Have the patient close gently but firmly on thebite-block to hold the film in position.

Figure 1-33.—Interproximal paralleling device.

Figure 1-34.—Paralleling device positioned for interproximalradiographs.

4. Slide the locator ring down the indicator roduntil the ring almost touches the surface of the patient'sface. Then, align the tube head using the same techniqueas previously described for the paralleling device.

5. Make the exposure. After making the exposure,put the exposed film in a lead lined container or behind aprotective screen. You are now ready to take theradiograph on the opposite side of the patient's mouth.

BISECTING-ANGLE TECHNIQUE

The following procedures describe this technique:

1. Program the X-ray machine for the discussedtime, mA settings, and kVp settings.

2. Position the patient so that the ala-tragus line isparallel with the floor, and the midsagittal plane isperpendicular to the floor.

3. Position the film packet in the patient's mouth.Hold the wing of the packet between your thumb andindex finger. Place the lower edge of the packet betweenthe tongue and the lingual surfaces of the mandibularteeth. Position the packet so that its anterior edgetouches the distal surface of the mandibular cuspid. Restthe wing of the packet on the occlusal surfaces of themandibular teeth. Instruct the patient to close slowly. Asthe patient's maxillary teeth contact your index finger,roll your finger out facially, permitting the patient'steeth to close on the wing (fig. 1-35). The film packet isnow positioned.

4. Set the vertical angulation of the tube head at+5° to +l0°.

1-23

Figure 1-35.—Patient closing on wing.

5. Center the tube head cylinder on the wing of thefilm packet. Be sure that the central X-ray beam passesthrough the embrasures as shown in figure 1-36.

6. Make the exposure. After making the exposure,put the exposed film in a clean paper cup and place in alead lined container or behind a protective screen. Youare now ready to take the radiograph on the oppositeside of the patient's mouth.

OCCLUSAL EXAMINATION

An occlusal examination is usually conductedwhen fractures of the jaw or gross pathologicalconditions are suspected. A typical occlusalradiograph (fig. 1-37) shows a large area of themaxillary or mandibular arch.

The occlusal film packet is shaped much like theperiapical packet, only larger. Unlike the periapical

Figure 1-36.—Centering tube head cylinder.

1-24

Figure 1-37.—Typical maxillary anterior occlusal radiograph.

and bitewing packets, the occlusal packet contains twoX-ray films. This allows different developing times tobe used for these films. The finished radiographs canthen be compared for diagnostic purposes.

Occlusal radiographs are exposed using the

bisected angle technique.

MAXILLARY OCCLUSAL RADIOGRAPHS

Maxillary occlusal radiographs are taken by using

the following procedures:

1. Set the X-ray machine at 10 mA, 90 kVp, and 60impulses (1 second). (Reduce the kilovoltage 5 kVp ifthe arch is edentulous. Use 70 kVp if the patient is achild.)

2. Position the patient so that the ala-tragus line isparallel with the floor, and the mid-sagittal plane isperpendicular to the floor.

3. Place the film in the patient's mouth. Occlusalfilms are normally very comfortable. Have the patientrelax the muscles of the mouth and cheek as much aspossible. The pebbled surface of the packet should betoward the occlusal surfaces of the maxillary teeth, andthe narrow side of the packet toward the patient’scheeks. To place the packet, retract one corner of thepatient’s mouth until the packet can be inserted. Positionthe packet far enough in the mouth so that it covers allthe teeth. Special care must be taken to avoid gaggingthe patient. Have the patient close gently but firmly onthe packet to hold it in place.

4. Position the tube head.

a. For maxillary anterior occlusal radiographs,set the vertical angulation of the tube head at +65°.Center the tube head cylinder on the bridge of the

Figure 1-38.—Projection of central ray (CR) for maxillaryanterior occlusal radiographs.

patient's nose so that the central X-ray beam will beprojected as shown in fig. 1-38.

b . For max i l l a ry pos te r io r occ lusa lradiographs, set the vertical angulation of the tube headat +75°. Center the tube head at the top of the patient'snose so that the central X-ray beam will be projected asshown in fig. 1-39.


MANDIBULAR OCCLUSALRADIOGRAPHS

Mandibular occlusal radiographs are taken byusing the following procedures:

1. Program the X-ray machine for 10 mA, 90 kVp,and 60 impulses (1 second). (Reduce the kVp setting foredentulous patients and children as discussed earlier.)

Figure 1-39.—Projection of central ray (CR) for maxillaryposterior occlusal radiographs.

1-25

2. Position the patient.

a . For mand ibu la r an te r io r occ lusa lradiographs, position the patient so that the ala-tragusline is at a 45° angle with the floor, and the midsagittalplane is perpendicular to the floor.

b. For mandibular posterior occlusalradiographs, position the patient so that the ala-tragusline and mid-sagittal plane are perpendicular to thefloor.

3. Place the film packet in the patient's mouth withthe pebbled surface toward the occlusal surfaces of themandibular teeth, and the short sides of the packet aretoward the patient's cheeks. Have the patient closegently on the packet to hold it in place.

4. Position the tube head.

a. For mandibular anterior occlusal radio-graphs, set the vertical angulation of the tube head at -10°. Center the tube head cylinder on the tip of thepatient’s chin so that the central X-ray beam will beprojected as shown in figure 1-40.

b. For mandibular posterior occlusalradiographs, set the vertical angulation of the tube headat 0°. Center the tube head cylinder beneath the patient'schin so that the central X-ray beam will be projected asshown in figure 1-41.

5. Make the exposures.

INFECTION CONTROL

It is extremely important to pay attention toinfection control when taking radiographs. Both theradiographic equipment and film can becomecontaminated and may result in the transmission ofinfectious agents. To protect themselves and the

Figure 1-40.—Projection of central ray (CR) for mandibularanterior occlusal radiographs.

Figure 1-41.—Projection of central ray (CR) for mandibularposterior occlusal radiographs.

patients, dental personnel must maintain infectioncontrol standards in the radiology area similar to thoseused in the DTR. Information and procedures on theDental Infection Control Program can be found inBUMEDINST 6600.10.

HANDWASHING

Follow rigid handwashing procedures whentreating a radiology patient. Wear gloves when placingintraoral films and handling contaminated filmpackets.

DARKROOM

Disinfect all counter surfaces daily, and any otherareas that might become contaminated such asdoorknobs, light switches, and other surfaces that youmight come in contact with.

FILM POSITIONING DEVICES

Film positioning devices should be disposable(single use) or heat sterilized between patients. Yourcommand should have an adequate supply of filmpositioning devices to treat your daily patient load. Ifsupplies are short, you may disinfect film positioningdevices between patients by immersion in an EPA-registered chemical disinfection such as a 2 percentglutaraldehyde. Rinse thoroughly after disinfection.Follow manufacturer's instructions for high-leveldisinfection.

PANORAMIC UNIT BITE-BLOCKS

Use a disposable panoramic unit bite block coverfor each patient. When disposable covers are notavailable, disinfect bite blocks as you would a filmholding device.

1-26

INTRAORAL FILM PACKETS

Intraoral film packets become contaminated when

they are placed in a patient's mouth during exposure.

We will explain procedures on how to handle and

process contaminated intraoral film packets from the

X-ray room to the dark room to avoid cross

contamination. Procedures using an automatic film

processor with and without a daylight loader are

explained next.

Automatic Film Processors Without a DaylightLoader

Procedures for using an automatic film processor

without a daylight loader are as follows:

1. Wearing disposable gloves, expose an intraoralradiograph.

2. Place intraoral film packets removed from thepatient's mouth directly into a clean paper cuppreviously set aside for this purpose. Do notcontaminate the cup with soiled gloves.

3. Transfer cup to dark room.

4. While wearing the gloves used to take theradiograph, open the film packets and drop the film ontoa clean paper towel without touching the film.

5. Discard film wrappers directly into a linedrefuse container to prevent contamination of thedarkroom work surfaces.

6. Place lead foil backing in a designated storagecontainer.

7. Remove gloves and feed the uncontaminatedfilm into the developer without special precautions.

8. Disinfect all areas and set up for your nextpatient.

Automatic Film Processors With a DaylightLoader

When using an automatic film processor with a

daylight loader, contamination of the fabric lightshield is likely to be a problem. Since there is no way to

disinfect this shield, disposable plastic film packet

covers should be used to eliminate contamination of

the fabric light shield by oral fluids and glove residue.

Daylight loaders should be used only when a darkroomis not available.

Disposable Plastic Film Packets

The following is a recommended technique forprocessing X-ray film with disposable film packetcovers when using a daylight loader:

1. Wearing disposable gloves, expose an intraoralradiograph film with a disposable plastic film packetcover on it.

2. Still wearing the contaminated gloves, open thedisposable plastic film packet containing the exposedX-ray film and using a sterile drop method, release theX-ray film into a clean paper cup previously set asidefor this purpose.

3. Dispose of contaminated plastic film cover andgloves in a lined refuse container. Wash hands toremove powder from gloves and dry.

4. Open daylight loader and place the clean papercup containing the exposed X-ray film inside. Close lid.

5. Place clean ungloved hands through fabric lightshield and open film packet. Process X-ray film.

6. Open daylight loader and separate lead foilbacking from film wrappers. Place lead foil in adesignated storage container.

7. Discard film wrappers and paper cup into a linedrefuse container.

Alternate Method When Not Using DisposableFilm Covers

Some X-ray departments may not have disposableplastic film covers for use with automatic filmprocessors with a daylight loader. The following is analternate method to prevent the fabric light shield frombeing contaminated:

1. Place the exposed film in a clean paper cuppreviously set aside for this purpose.

2. Remove soiled gloves and put on a pair of cleangloves.

3. Place the cup through the top of the processingbox and close the lid.

4. Place clean gloved hands through the fabriclight shield as shown in figure 1-42, unwrap the filmpacket, and drop the film onto the surface inside theloader.

5. Place the film wrapping into the cup. Removethe gloves, turn them inside out, and place them in thepaper cup.

1-27

Figure 1-42.—Placing clean gloved hands through fabric light shield with a daylight loader.

6. Carefully grasp the film by its edges to avoidtransferring powder from your hands onto the film, dropthe film in the chute for developing.

contaminated. Change paper or plastic headrest covers

after each patient.

7. Remove hands from the loader, lift the lid, anddispose of paper cup and waste. Ensure all lead foil iscollected and stored.

X-RAY TUBEHEAD ANDCONTROLS

8. Wash hands thoroughly.

9. If the fabric light shield sleeves becomecontaminated, they may be gas sterilized.

X-RAY CHAIR

Use an EPA-registered intermediate-leve1disinfectant on the X-ray chair daily or when visibly

Cover those areas contacted by the staff and

patients with plastic wrap (fig. 1-43) or disposable

drapes. Be careful that these coverings do not interfere

with the flow of cooling air to the X-ray tube head.

Change after each patient. When wiping the tubehead

and controls with liquid disinfectants, exercise care to

prevent disinfectant from leaking into the tube head

seams and exposure controls.

Figure 1-43.—X-ray tube head covered with plastic wrap.

1-28

FILM PROCESSING

After the patient has been radiographed, the X-rayfilm is processed to produce the finished radiographs.There are five basic steps involved in processing X-rayfilm: developing, rinsing, fixing, washing, and drying.You can process the film manually, or use an automaticfilm processor. For the most part, manual processing isused for a backup method for the automatic filmprocessor and will not be discussed. If your commandhas manual processing capabilities, refer to themanufacturer's operating instructions. Because ourdiscussion concerns both darkroom procedures andfilm processing, we will cover the darkroom first.

DARKROOM PROCEDURES

The darkroom has two sources of illumination:white light and safelight. A white light is a standardceiling light. It provides regular illumination formixing solutions and cleaning the darkroom. Anunwrapped, unprocessed X-ray film must never beexposed to white light.

Exposed film is useless. A safelight, whichcontains a 15 watt bulb with a special filter, is the onlysafe source of illumination in the darkroom whenprocessing intraoral and panoramic X-ray film. Thesafelight must be located no less than 4 feet from thework surface so that you can open film packets andprocess films safely. Limit the length of exposure ofundeveloped dental films to the safelight for no morethan 2 minutes. Films left out exceeding this timemight get a fogged image (discussed under faultyradiographs).

Occasionally, films are ruined because of lightleakage. White light may leak through the filter on thesafelight or it may leak into the darkroom from anoutside source. A simple test will enable you to detectleakage.

To check for possible light leakage from an outsidesource, perform the test with all lights off, includingthe safelight.

Take a packet of unexposed X-ray film, open thefilm packet, and remove the film. Lay the film on theworkbench, and place a penny over it for a period of 5minutes. Then, process the film using the proceduresprovided later in this chapter. The processed filmshould show no image. If the outline of the penny canbe seen, there is light leakage and you should informyour supervisor. You should perform this test at every

location in the darkroom where unwrapped film isbeing processed.

SAFETY PRECAUTIONS

Because of the alkaline and acid nature of thedeveloper and fixer solutions, minor chemicalirritation or burns can occur when they come in contactwith the skin, the eyes, and the mouth. Use cautionwhen stirring or mixing solutions. Always wear rubbergloves and protective eye wear or a protective faceshield and an apron when working around thesesolutions. If the solutions come in contact with theskin, flush the area with large amounts of water. If thesolutions accidentally splash into the eyes or mouth,flush with large amounts of water and immediatelyseek medical attention. Fixer solution can stain anddiscolor clothing.

AUTOMATIC PROCESSING

Automatic processing is the most commonly usedmethod of processing dental radiographs in the Navy.The automatic film processor mechanically transportsexposed X-ray film through the developing, fixing,washing, and drying cycles. Automatic processing isquicker than manual processing, and it producesfinished radiographs of uniform quality. A variety ofautomatic film processors are in use in the Navy andthey can be generally classified as small or large.

Large Automatic Film Processor

The large automatic processor (fig. 1-44)processes all sizes of dental radiographs includingintraoral, occlusal, panoramic, and 8-inch x 10-inchcephalometric films.

This processor will be located in the darkroom.The X-ray film must be inserted in the processor undersafelight conditions. Large automatic processors canbe equipped with daylight loaders, eliminating theneed for a darkroom.

Operational Check

Perform the operational check at the beginning ofeach day to ensure that the processor is in goodworking order. It is a complex piece of equipment, soread the manufacturer's operational manual verycarefully. Never attempt to repair the componentsinside the processor. There are a variety of largeautomatic processors used in the Navy today. Theautomatic processor's components, procedures, and

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Figure 1-44.—Large automatic processor.

Figure 1-45.—External components of a large automatic processor.

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maintenance described next are for the specificprocessor shown. If you work with a different make ormodel of an automated processor, refer to thatmanufacturer's operational manual for operatinginstructions.

Figure 1-45 shows the main external componentsof the large automatic film processor. Figure 1-46shows the internal components when the top cover isopened from the processor. Figure 1-47 shows thefunctions of the operator’s control panel.

The daily operational check of the large automaticprocessor is performed as follows:

1. Plug the power supply cable into the poweroutlet.

2. Check the solutions. Most automatic processorsare equipped with a replenisher, which automaticallyreplenishes solutions when the power is turned on. Anautomatic processor without an automatic replenisherrequires that you manually replenish the developer andfixer solutions. Pour the solutions slowly to avoidsplashing. Direct the pouring stream to the center of thetank away from the drain tubes.

3. Turn on the external water supply valve. Thisvalve is normally located close to and above theautomatic processor. If not equipped with externalwater supply, change the water in wash water containerand refill with fresh water.

4. Activate the automatic processor by depressingthe power on switch. If equipped with an automaticreplenishing system, the internal oscillating pumps willnow cycle and fill the solution tanks to their properlevels. When the low solution level lamp has gone out,the solution heater will start and the transports will turn.Do not process films at this time.

5. After 10 to 15 minutes, The ready lamp willilluminate. This indicates that the proper processingtemperature has been reached.

6. Depress the run/standby switch to the runposition. Insert an 8-inch x 10-inch cleaning film intothe processor receiving tracks. The cleaning film cleansthe rollers of accumulated deposits, dirt, and debris. Usea new cleaning film every week. After the cleaning filmexits the processor, depress the run/standby switch tothe standby position.

Figure 1-46.—Internal components of a large automatic processor.

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7. Do not depress the on/off switch. It should

remain on for the entire working day. As long as the

on/off switch is in the on position, several functions will

occur throughout the day.

a. Approximately every 4 minutes, theoscillating pumps will cycle for several seconds. Thisaction will maintain a uniform solution strength.

b. The solution heater will maintain a properprocessing temperature.

c. The solution agitators will intermittentlycycle, keeping the solutions well mixed.

d. The roller transports will intermittently turn,allowing the solutions to wet the rollers. This willprevent dried solution deposits from forming.

e. At the end of the working day, depress theon/off switch to the off position.

8. Some models may require that you turn the

water inlet valve on the plumbing line to the off

position.

Procedures For Processing Film

If you are processing a large quantity of X-rayfilm, you must avoid any mixup. To do this, after youinsert one patient’s X-ray films, wait 15 seconds beforeinserting the next patient’s films. After inserting theX-ray films of each patient, set the X-ray mount,envelope, or identification label aside, making sure to

Figure 1-47.—Operator's control panel.

keep them in the order in which they were processed.This will help you match the processed radiographs tothe patient’s unit, envelope, or identification labelwhen the film exits the processor.

To process X-ray films, you should follow these

procedures:

1. The recommended complete processing time is5 minutes at normal speed. If your processor has anendo speed button, this can process X-rays in 2 minutes.Endo speed is used when the dentist wants to process thefilm quickly. The developer temperature should be at82°F (28°C) and the water temperature 50°F to 90°F.

2. Depress the run/standby switch to the runposition to begin automatic processing.

3. Insert the X-ray film. Unwrap the film and insertit into the film receiving slot. (Remember to open thefilm under safelight conditions). The automaticprocessors can have up to six tracks to accept intraoralfilms. To prevent overlapping, feed the film lengthwiseinto every other track (e.g., insert first three films intotracks 1, 3, and 5; insert the second three films intotracks 2, 4, and 6). Feed large films lengthwise one at atime, allowing at least 15 seconds between films. Allow15 seconds to expire after the last film disappears beforeinserting another film or turning on the lights or openingthe darkroom door. Once the films have been inserted,the total processing time will take 5 minutes unless onthe endo cycle.

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To obtain the best quality radiographs, follow thefilm manufacturer's processing guidelines. Ifradiographs processed at 5 minutes and 82°F (28°C)are too dark, reduce the X-ray exposure time setting.

When the films have been processed, the finishedradiographs will exit the processor on the film trackand fall into the film receptacle. When the last film hasexited the unit, depress the run/standby switch to thestandby position. The unit will remain on standbythroughout the day.

Securing The Processor

The processor should be secured at the end of theday. The securing procedures are as follows:

1. Depress the on/off switch to the off position.

2. Turn the water supply valve to the off position.(Some models without water plumbing will not requirethis step.)

3. Unplug the power supply cable.

4. Wipe the cover and housing of the processorwith a damp sponge or cloth.

Chemistry Change

Change the developer and fixer at a minimum ofonce every 3 to 4 weeks. If a large quantity of X-rayshas been processed, change the developer sooner.Replenish the solutions following the manufacturer’sinstructions.

NOTE: The solutions used for automaticprocessing are not the same as those used for manualprocessing.

Maintenance Schedule

You are responsible only for user maintenance onthe processor; repairs are the responsibility of thedental equipment repair technician.

Monthly maintenance consists of cleaning theroller transports and solution tanks. Weeklymaintenance consists of soaking the transport rollers,solution agitators, and other removable internal partsfor 5 to 10 minutes with a processor cleaner.

NOTE: Any time the processor cover is lifted andmaintenance is being performed, you must wear asafety face shield, apron, and protective gloves.

The quality of the processed radiographs arereflected in the maintenance of the processor.

Improper maintenance can cause radiographs of poordiagnostic quality, and may cause patients to havetheir radiographs taken over. Always followmanufacturer’s instructions for correct maintenanceand operating procedures.

To keep the processor in good operating condition,do not place heavy objects on top of the processor oruse the top as a film loading or storage area. Do not turnthe power switch on when the solution tanks are empty.Also, do not use steel wool or abrasive scouringpowder when cleaning tanks or metal parts of theprocessor.

Small Automatic Film Processor

The small automatic processor processes onlybitewing and periapical dental radiographs. Theprocessor solutions are self contained and require noplumbing.

The small processor in figure 1-48, may be locatedin a darkroom, but because of its small size andcompatibility with a daylight loader, it is commonlyfound in endodontic departments, small dental clinics,and on board Navy ships where no darkroom isavailable.

Operational Check and Processing

Refer to the instruction manual for the assemblyand disassembly of processor components. The dailyoperational check for the small automatic processor isperformed as follows:

1. Remove process cover and check the level of thesolutions. Tank capacity for the developer and fixertanks is 1 quart each. The wash tank holds 1 1/2 quarts ofwater. Figure 1-49 shows the solution tanks.

2. Plug the power supply cable into the poweroutlet.

3. Depress power (left) switch (fig. 1-50). Directlyabove the left switch, the red light goes on, indicatingthe chemistry heaters are on. When the green light(right) flickers (in about 15 minutes, depending on roomtemperature) X-rays may be processed.

4. To process films, depress the process (right)switch. The green ready light will alternate betweenflickering and full on, indicating an optimum 74° to76°F temperature is being maintained.

5. Refer to the manufacturer's instruction manualprocedures for processing bitewing and periapicalfilms.

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Figure 1-48.—Small automatic processor.

Figure 1-49.—Solution tanks.

Securing The Processor Maintenance Schedule

Turn off the power switch (left) and unplug power

supply cable from outlet.

Daily, wipe the external parts of the processor witha dry or slightly moist, lint free cloth. Refer to theinstruction manual for the complete maintenance

Chemistry Change schedule.

Change the developer and fixer every 300 to 350

films or in 2 weeks, whichever is sooner. The water in

the wash tank is changed every 100 to 125 films or in 1

week, whichever is sooner. When changing chemicals,

clean the tanks with water and dry prior to placing new

chemicals in them. Use the same safety precautions as

mentioned before when handling chemicals.

FAULTY RADIOGRAPHS

Faulty radiographs are usually caused by theincorrect positioning of the film packet or the tubehead; incorrect kVp, mA and time setting; or byincorrect processing procedures.

Some common causes of faulty radiographs due totube head and film misalignment have already been

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Figure 1-50.—Operator control panel.

discussed (e.g., incorrect horizontal angulationproduces superimposed radiographic images, andincorrect vertical angulation produces images that maybe foreshortened or elongated.) The following areadditional causes of faulty radiographs:

No image (fig. 1-51): The film was immersed inthe fixer before the developer. If the film is completelyclear, it was never exposed.

Very light image (fig. 1-52): The film wasunderexposed (kilovoltage too low); the developer was

Figure 1-51.—No image. Figure 1-53.—Partial image (cone cutting).

Figure 1-52.—Very light image.

weak; or the film was not left in the developer longenough.

Very dark image: The film was over-exposed(kilovoltage too high); the developer was too warm; orthe film was left in the developer too long.

Partial image (fig. 1-53): The film was notcompletely immersed in the developer; the film cameinto contact with other film or the side of the tank whilein the developer; or the film or tube head was incorrectlypositioned (cone cutting).

Blurred image: The patient or tube head movedduring the exposure.

Fogged film: The film was outdated orcontaminated; the film was overexposed by being heldtoo close to the safelight; the film was exposed to strayradiation, excessive heat, chemical fumes, or lightleaksin the darkroom; the developer was improperly mixed,contaminated, or too hot.

Streaked or stained film: The film wasinsufficiently washed or fixed; the processing solutionswere dirty; or the film hanger was dirty.

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Reticulation: There was a too rapid change intemperature during processing (e.g., the film was takenfrom a warm developer to a cold rinse).

Crescent-shaped lines (fig. 1-54): The filmpacket was creased or bent.

Herringbone image (fig. 1-55): The wrong sideof the film, packet was facing the source of the X-raybeam during exposure causing the embossing patternfrom the lead backing to appear on the film.

Figure 1-54.—Crescent-shaped lines on film.

Figure 1-55.—Herringbone image.

Black areas: The film was pulled too rapidly

from its black paper wrapping, causing a discharge of

static electricity.

White spots: The developer failed to work on

these areas because of dirt or air bubbles.

Foreign object image (fig. 1-56): Dentures or

other objects were in the patient’s mouth during the

exposure.

FILM VIEWERS

The film viewer consists of a metal case with aback-lighted screen. The viewer is used to mount andexamine radiographs. Figure 1-57 shows a typical deskmount film viewer. Never light the film viewer in thedarkroom when you are working with unwrapped,unprocessed film. Keep the viewer screen clean at alltimes.

MOUNTING RADIOGRAPHS

After processing the X-ray film, you will mountthe finished radiographs in cardboard or plasticholders. Mounting makes the radiographs easy toview, keeps them in a chronological order, and protectsthem from damage.

Mounted radiographs may be viewed from eitherthe front or back of the mount. If viewed from thefront, the teeth appear on the film as if you werelooking directly into the patient's mouth. If viewedfrom the back, the teeth appear on the film as if youwere sitting on the patient's tongue looking out.Always mount X-rays in anatomical order. After youmount the radiographs, file the mount in the patient'sDental Record. There will be times when the dentalofficer will want to retain the radiographs fordiagnostic purposes (e.g., endodontics). These arenormally placed in a drug envelope, labeled and dated,and placed in the dental record.

Figure 1-56.—Foreign object image.

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Figure 1-57.—Desk mount film viewer.

INTERPROXIMAL (BITE-WING)MOUNTING

Figure 1-58 shows a serial mount for inter-proximal(bite-wing) radiographs. The mount contains slots formounting five pairs of interpromixal radiographs for apatient taken at different times and mounted inchronological order. Serial mounting enables thedental officer to compare radiographs taken atdifferent time intervals to detect changes in thepatient's oral structures.

The front of the mount contains spaces for thepatient's name and social security number, mountnumber, and the date of each exposure. Fill in thisinformation whenever you start a new mount. Afteryou have completed the necessary information on thefront side, turn the mount over and lay it face down on atable top.

Place the radiographs on a flat, dry surface with theconvex surface of the identifying "dimple" towardthe observer. Pick up a radiograph by the edges. Hold itup to the, film viewer. The line representing theocclusal surface of the bicuspids and molars shouldgradually curve upward, forming one-half of a smile. Ifthe line curves upward on the right, slide theradiograph into the right-hand slot on the back of themount with the upward curve toward the outside of themount. Keep the raised dimple facing you. If the linecurves upward on the left, slide the radiograph into theleft-hand slot. If both radiographs are mountedcorrectly, they will appear as shown in figure 1-58,forming a complete smile. Each time an additional pairof inter-proximal radiographs is mounted, enter the dateon the line beneath the mounting slots. Figure 1-58.—Interproximal (bitewing) serial mount.

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FULL MOUTH PERIAPICALMOUNTING

Figure 1-59 shows a full mouth periapical filmmount. The mount contains 14 slots for periapicalradiographs and 2 slots for interproximal (bite-wing)radiographs.

W h e n m o u n t i n g f u l l m o u t h p e r i a p i c a lradiographs, you will be working with 14 radiographs;take care to sort and mount them correctly. To do this,you must be able to recognize certain maxillary andmandibular anatomical landmarks.

the teeth (B in fig. 1-60). The wavy white line identifiesthe floor of the maxillary sinus. This white line is notfound in radiographs of the mandibular arch.

Mandibular Cuspid and BicuspidAreas

Radiographs of these areas show a fine network oftiny white lines around and below the roots and a darkarea in the cuspid area representing the mental foramen(E in fig. 1-60).

Maxillary Molar AreaANATOMICAL LANDMARKS

During the following discussion, locate eachanatomical landmark on figure 1-60. The landmarksare indicated by arrows.

Maxillary Incisor Area

Radiographs of this area usually show a largewhite region caused by the bone of the nasal septum (Ain fig. 1-60).

Mandibular Incisor Area

Mandibular incisors are smaller than maxillaryincisors. The mandibular incisor area has a network of tinywhite lines around and below the roots (D in fig. 1-60).

Maxillary Cuspid and Bicuspid Areas

Radiographs of these areas usually show adistinct wavy white line above or near the apices of

Radiographs of these areas show the maxillaryarch and the roots of the maxillary molars curvingslightly toward the rear of the mouth (C in fig. 1-60).Maxillary molars have three roots, they tend to beindistinct on radiographs. In addition, the radiographswill usually show a distinct wavy white line above ornear the apexes of the teeth.

Mandibular Molar Area

Mandibular molars show two roots that aredistinct on radiographs. The mandibular nervecanal frequently shows as a dark, narrow bandrunning horizontally under the apexes of themandibular molars. The mandibular arch and theroots of the molars curve slightly toward the rear ofthe mouth. An impacted third molar will often bepresent on radiographs of the mandibular molarareas (F in fig. 1-60).

Figure 1-59.—Full mouth periapical mount.

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Figure 1-60.—Maxillary and mandibular radiographic landmarks.

MOUNTING PROCEDURES

Place all the radiographs in the full mouthperiapical series on a dry, flat working surface with thedimple side up. On the front of the film mount, enterthe patient’s name, social security number, rank/rate,the date, and the name of the dental treatment facility.Place the mount face down on the working surface.The two small arrows on the back of the mount shouldpoint toward you. Follow these steps to mount theradiographs:

1. Check each radiograph and make sure that thesurface with the raised dimple faces you.

2. Mount interproximal radiographs. If inter-proximal (bite-wing) radiographs are included in thefull mouth series, insert them in the slots provided aspreviously discussed.

3. Divide the radiographs into maxillary andmandibular groups. Using the film viewer, locate theanatomical landmarks discussed earlier. The maxillaryradiographs are inserted in the 7 slots across the top ofthe film mount and the mandibular radiographs in the 7slots across the bottom.

4. Insert the maxillary radiographs. First, identifythe radiograph of the central incisor area. Keeping theside with the raised dimple facing toward you, rotate the

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radiograph until the incisal edges of the teeth pointdown. With the back of the mount toward you, slide theradiograph into the incisor slot. When the radiograph isproperly mounted, the side with the raised dimple willface you, and the incisal edges pointing down towardthe center of the mount.

5. Work outward from the central incisor slot,inserting the rest of the maxillary radiographs in thefollowing order: cuspid areas, bicuspid areas, and molarareas.

6. Insert the mandibular radiographs. Start with theradiographs of the central incisor areas and workoutward. As before, the raised dots will be toward youand the incisal/occlusal surfaces of the teeth should bepointing upward toward the center of the mount.

When you have inserted all of the radiographs,hold the mounted radiographs up to the viewer. Doublecheck to see that each radiograph is mounted correctly.

PANORAMIC RADIOGRAPHS

The panoramic X-ray machine is used to producean extraoral radiograph that shows both dental archesand the temporomandibular joints (fig. 1-61). Theradiograph is made by rotating the tube head and filmaround the patient while the patient remains stationary.Because of the different manufacturers and models of

panoramic X-ray machines used in the Navy, thisoperation and maintenance will vary. Always refer tomanufacturer's instruction manual prior to use.

The panoramic X-ray machine and control panelare shown in figures 1-62 and 1-63. Refer to thesefigures throughout the following discussion. You mustbe thoroughly familiar with the components shownbefore operating the machine.

OPERATIONAL CHECK

The operational check for the panoramic X-raymachine is accomplished without a patient. Toperform the operational readiness check, perform thefollowing procedures as follows:

1. Turn on the pilot switch; the pilot light willilluminate.

2. Set the kVp selector switch to the desiredvoltage. Adjust the kVp meter as a reference for thedesired kVp setting.

3. Select the mA settings, to be used. Adjust themaccording to the manufacturer's instructions. When youfind the mA and kVp settings that give the best results,enter them on a technique values chart. Remember eachmanufacturer's film is different, so follow therecommendations.

Figure 1-61.—Typical panoramic radiograph.

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Figure 1-62.—A panoramic X-ray machine.

Figure 1-63.—A panoramic control panel.

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W A R N I N G : W h e n p e r f o r m i n g t h eoperational check, keep the collimatorcovered with the lead cap.

PREPARING THE FILM

When the X-ray machine is operational, preparethe panoramic film. Load the film into a cassette drum,label it, and then mount it in the cassette drumassembly on the X-ray machine. To load and mount thecassette drum, follow the manufacturer's instructions.

LABELING THE CASSETTE

The cassette is labeled for the purposes oforientation and patient identification.

To properly orient the finished radiograph soyou can distinguish the left from the right side of thepatient's dentition, tape a lead letter "R" in thelower right-hand corner on the outside of thecassette cover.

There are two ways to label the cassette for patientidentification. You can use a self-adhesive label or anX-ray film identification printer. Follow themanufacturer's instructions when using the printer.The patient information includes: the patient's name(last name, first name, and middle initial), familymember prefix code, social security number, and thedate of the exposure.

REQUIREMENTS FOR A GOODPANORAMIC RESULT

Follow the manufacturer's operating instructionsfor complete operation of the panoramic X-raymachine before you attempt to use it. The following is

a list of important procedures that must be followed toensure a good quality X-ray is produced.

as straMake sure patient's back and cervical spine areight as possible.

Check that the patient's mid-sagittal plane iscentered within the unit.

Ensure the patient's frankfurt plane is horizontal.

Check that the anterior maxil lary andmandibular teeth are located on the indents of the bite-block. If the patient's bite is abnormal, adjust mandibleforward or backward to compensate.

Observe patient to assure there is no movementduring the radiographic procedure.

OPERATING THE PANORAMIC-RAYMACHINE

With the machine operational and the film cassettedrum in the cassette drum assembly, you are now readyto take the radiograph on the patient. Follow themanufacturer's instructions for patient positioning andoperation. When the patient is positioned, explain theexposure procedures. Then make the exposure andprocess the film. You must wait 5 minutes betweenexposures to prevent overheating of the X-ray head.

USER MAINTENANCE

The panoramic X-ray machine requires very littleuser maintenance. Wipe the metal and painted partswith a soft, dry cloth daily.

Never attempt to repair the panoramic X-raymachine yourself. Report malfunctions to yoursupervisor. All repairs are the responsibility of thedental equipment repair technician.

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CHAPTER 2

DENTAL EXAMINATIONS

INTRODUCTION PATIENT PREPARATION

The dental examination is one of the basicprofessional services provided by the Navy dentalteam. Soon after you entered the military service, youreceived your first dental-oral examination todetermine your dental health. Throughout yourservice with the Navy, you will receive annual orperiodic dental examinations. The results of theseexaminations are recorded in your individual U.S.Navy Medical Outpatient and Dental TreatmentRecord (NAVMED 6150/21-30). The preparation ofthe NAVMED 6150/21-30 is discussed in DentalTechnician, Volume 1, chapter 2. The ForensicExamination Section, which is located on the insideback cover of the NAVMED 6150/21-30, will bediscussed in this chapter s ince i t covers anexamination.

Your responsibility is to assist the dentist in allareas of dental examinations. You must be able tounderstand and complete various dental forms used inthe examination process that become a part of theNAVMED 6150/21-30. Information on dentalexaminations and related forms can be found in theManual of the Medical Department, NAVMED P-117,chapters 6 and 15.

Dental examinations are performed by dentists indifferent areas of the dental clinic. The Oral DiagnosisDepartment has the responsibility of providing dentalexaminations and holding "sick-call" hours, whiledentists and auxiliary personnel (hygienists and DentalTechnicians) in other departments of the dental clinicalso perform oral examinations. This chapterconcentrates on your duties in pre-examination,examination types, occasions for dental examinations,dental classifications, designations, charting andabbreviations, recording dental treatment, additionaldental treatment forms, and patient dismissal.

PRE-EXAMINATION DUTIES

Before seating a patient for a dental examination,ensure that the operatory is neat and professional inappearance. Make sure the area is clean and theequipment is disinfected.

The patient may be nervous, so try to put him/her atease by using the communication skills that werediscussed in Dental Technician, Volume 1, chapter 2,"Technical Administration and Responsibilities."

Introduce yourself and ask the patient for his or herdental record. Open the record and scan the DentalHealth Questionnaire, NAVMED 6600/3. Lookspecifically for "yes" answers if the questionsconcerning contagious or infectious diseases, such asHepatitis (Type), Human Immunodeficiency Virus(HIV), cold sores (herpes, etc.) were checked. When apatient has a "yes" answer, notify the dentist beforetreatment.

When the patient is seated, make him or her ascomfortable as possible. Adjust the headrest and placethe chair in the working position favored by the dentist,usually the fully reclined position shown in figure 2-1.In this position, the patient's head is level with thedentist's elbow when the dentist is seated on the dentalstool.

After you have seated the patient and positionedthe chair, turn on the operating light. To avoid shiningthe light in the patient's eyes, focus the light beam onthe area beneath the patient's chin. Then, turn off thelight until the dentist is ready to start the examination.When the dentist is ready, turn on the light and rotatethe light up to the mouth.

Next you will need a patient napkin to drape thepatient. A patient napkin holder attaches the patientnapkin in place around the neck area. If the patient is awoman wearing lipstick, give her a tissue and politelyask her to remove the lipstick before the examinationbegins. If the patient is wearing dentures or removablepartial dentures, ask him/her to remove them and placethem in a cup of water. The dentist will need themstanding by to evaluate proper fit and condition duringthe exam.

A patient who is wearing corrective glasses shouldbe asked to leave them in place during the exam, whilea patient not wearing corrective glasses should begiven eye protection.

2-1

Figure 2-1.—Dental chair in working position.

INSTRUMENT/EQUIPMENTPREPARATION

Once the patient is ready, prepare the necessaryexamination instrument and equipment for use. Youmust maintain an aseptic technique in the DentalTreatment Room (DTR). Throughout the procedure,take care to prevent sterile instruments from beingcontaminated. Place the sterile instrument pack on thebracket table. Open the oral exam instrument pack,leaving the items on the sterile wrapping paper asshown in figure 2-2. Some commands use peel packsfor the exam pack. In this case, the instruments shouldbe placed on bracket table covers (paper sheets). Atthis point you should have completed all of thepreparation procedures. After you have doublechecked the area ensuring everything is ready, notifythe dentist that the patient is ready.

EXAMINATION DUTIES

During the dental exam, you are responsible forassisting the dentist and recording information ondental treatment forms and records.

Some of the typical tasks you may perform whenassisting the dentist include:

Taking the patient's vital signs (blood pressureand pulse). This is discussed in chapter 9 ofthis volume, "Dental Treatment RoomEmergencies."

Drying the teeth with the air syringe anddirecting the air on the mouth mirror to preventfogging.

You may be required to record treatment informa-tion on the following dental treatment records andforms.

Dental Treatment Record, NAVMED 6150/21-30

Dental Health Questionnaire, NAVMED 6600/3

Current Status Form

Dental Examination Form, EZ603 and EZ603A

Report of Medical Examination, SF 88

Consultation Sheet, SF 513

2-2

Figure 2-2.—Examination instrument setup.

EXAMINATION TYPES

The four different types of dental examinations arediscussed in the paragraphs that follow. To ensureuniformity in nomenclature and definitions, dentalexaminations are classified by type.

TYPE 1, COMPREHENSIVEEXAMINATION

This is the ideal examination, for it is the mostextensive dental examination. The dentist will performa comprehensive hard and soft tissue examination thatincludes: oral cancer screening examination; mouth-mirror, explorer, and periodontal probe examination;adequate natural or artificial illumination; pano-graphic or full-mouth periapical, and posteriorbitewing radiographs; blood pressure recording; andwhen indicated, percussive, thermal and electrical test,transillumination, and study models. Included arethose lengthy clinical evaluations required to establisha complex clinical diagnosis and the formulation of atotal treatment plan. For example: treatment planningfor full-mouth reconstruction; determination of theetiology or differential diagnosis of a patient's chief

complaint, such as temporomandibular joint (TMJ)dysfunction and associated oral facial pain; or lengthyhistory taking relative to determining a diagnosis, orin-processing examination for officer candidates.

TYPE 2, ORAL EXAMINATION

Comprehensive hard and soft tissue examination,which will include: oral cancer screening examination;mouth-mirror, explorer, and periodontal probeexamination; adequate natural or artificial illu-mination; appropriate panographic or intraoralradiographs as indicated by the clinical examination;and blood pressure recording. An appropriatetreatment plan will be recorded. This type is theroutine examination, which is normally done only onetime per treatment regimen per patient, unlesscircumstances warrant another complete examination.

TYPE 3, OTHER EXAMINATION

This examination consists of diagnost icprocedures as appropriate for: consultation betweenstaff or staff residents; observation where no formalconsult is prepared; certain categories of physical

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examinations; and emergency oral examinations forevaluation of pain, infection, trauma, or defectiverestorations.

TYPE 4, SCREENING EVALUATION

This type of examination consists of a mouth-mirror and explorer or tongue depressor examinationwith whatever illumination is available. This categoryincludes the initial dental processing of recruitswithout necessarily being examined by a dentist orother screening procedures. A qualified dentalassistant or dental hygienist may perform a type 4examination.

OCCASIONS FOR DENTALEXAMINATIONS

Dental examinations are performed on variousoccasions. The type of the examination performed willdepend on what the patient needing an examinationrequires (i.e., retirement, annual, etc.).

ACCESSION

All Navy and Marine Corps personnel who enterthe military service will have a dental recordestablished with an accession examination andradiographs.

PERIODIC DENTAL EXAMINATIONS

Dental examinations of all active duty Navy andMarine Corps personnel must be conducted annuallyand on other appropriate occasions to establish theneed for dental treatment and verify dental records.Periodic dental examinations access the readinessstatus of active duty Navy personnel. The annualexamination should normally be a type 2 examination.

SUITABILITY FOR OVERSEASASSIGNMENT (OVERSEAS SCREENING)

The procedures for the medical and dentalevaluation of Navy and Marine Corps members andtheir accompanying family members, who areundergoing suitability processing for overseasassignment, are provided in NAVMEDCOMINST1300.1.

Based upon the findings of the dental examination,a dental off icer recommends sui tabil i ty orunsuitability of a member and family members foroverseas assignment. This is documented on a

NAVMED 1300/1, Medical and Dental OverseasScreening Review for Active Duty or Dependent. Theexamining dentist will complete Part II: Dental

Screening (fig. 2-3) on the NAVMED 1300/1.

The ultimate responsibility rests with themember's commanding officer to approve ordisapprove the member or family members foroverseas assignment.

PERIODICITY OF MEDICALEXAMINATIONS (PHYSICALS)

As a part of each member's medical physicalexamination, a dentist must examine the member andrecord the results on the Report of Medical

Examination, SF-88 (covered later in this chapter).Entries are also made on the member's EZ603, andfiled in the NAVMED 6150/21-30.

All active duty members and reservists will havemedical examinations completed as follows:

Upon entry to enlisted or commissioned active

duty

At intervals of 5 years through age 50

At intervals of 2 years through age 60

Annually after age 60

SEPARATIONS, RETIREMENTS ANDSPECIAL PROGRAMS

Dental examinations are required for personnelwho separate from the Naval Service, retire, or applyfor special programs. The Manual of the Medical

Department, NAVMED P-117, chapters 6 and 15,outlines procedures for these examinations.

DENTAL CLASSIFICATIONS

The Navy Dental Corps has a uniform system forrecording the results of a dental examination. It is aclassification system that lets the provider determinethe dental status of each individual and establishespriorities of treatment. Numbers are used to recordone of four possible dental classifications. Eachclassification is carefully determined using prescribedcriteria and is accurately recorded. The following is a

description of each classification.

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Figure 2-3.—NAVMED 1300/1, Part II: Dental Screening.

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CLASS 1

This classification is for patients who do notrequire dental treatment or reevaluation within 12months. Class 1 patients must meet these conditions:

No dental caries or defective restorations.

Arrested caries for which treatment is notindicated.

Healthy periodontium, no bleeding on probing;oral prophylaxis not indicated.

Replacement of missing teeth not indicated.

Unerupted, partially erupted, or malposed teeththat are without historical, clinical, orradiographic signs or symptoms of pathosis andare not recommended for prophylactic(preventive) removal.

Absence of temporomandibular disorders;stable occlusion.

CLASS 2

Class 2 is the classification for patients who haveoral conditions that the examining dentist feels if nottreated or followed up, have the potential but are notexpected to result in dental emergencies within 12months.

CLASS 3

Class 3 is the classification for patients who haveoral conditions that the examining dentist expects willresult in dental emergencies within 12 months if nottreated. Patients should be placed in class 3 when thereare questions in determining classification betweenclass 2 and class 3.

CLASS 4

Class 4 is the classification for patients whorequire a dental examination. This includes patientswho require annual or other required dentalexaminations and patients whose dental classificationsare unknown.

DESIGNATIONS, CHARTING, ANDABBREVIATIONS

The designations and abbreviations are to be usedwhen making entries in a patient's EZ603 or EZ603A(dental continuation sheet). The names of permanentand deciduous teeth and numbers that correspond with

them have been discussed in Dental Technician,Volume 1, chapter 4.

TOOTH SURFACES

The following designation of tooth surfaces areused to record pathologic conditions and subsequentrestoration of teeth:

Surface Designation

Facial (labial and buccal) F

Lingual L

Occlusal

Mesial

O

M

Distal

Incisal

D

I

Combinations of the designations must be used toidentify and locate caries, and to record treatmentplans, operations, or restorations in the teeth involved;for example, 8-MID would refer to the mesial, incisal,and distal aspects of a right maxillary central incisor;22-DF, the distal and facial aspects of a left mandibularcuspid; and 30-MODF, the mesial, occlusal, distal, andfacial aspects of a right mandibular first molar.

GENERAL CHARTING

As a Dental Technician, a large portion of yourtime during an examination involves recordingexisting restorations and current diseases andabnormalities in the patient’s dental records. You mustfully understand how and where to record thisinformation. Dental chart markings have beenstandardized so the original dental condition, diseasesand abnormalities (treatment needed), and treatmentscompleted may be identified. This assists in efficientcon t inu i ty o f t r ea tmen t and may es t ab l i shidentification in certain circumstances.

STANDARD ABBREVIATIONS ANDACRONYMS

The use of standard abbreviations and acronyms isnot mandatory, but it is desirable for expediency.Dental forms used to record dental treatment havelimited amounts of space to write on. Use onlyabbreviations and acronyms that will not bemisinterpreted. When you record treatment, ensureyou correctly spell all terms. Well known medical andscientific signs and symbols such as: Rx (prescription),

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WNL (within normal limits), BP (blood pressure) andO2 (oxygen) may be used in recording dentaltreatment. The following abbreviations and acronymsare authorized:

Acute Necrotizing Ulcerative Gingivitis

Assessment

All caries not removed

Amalgam

Anesthetic (thesia)

Bite-wing radiographs

Camphorated paramonochlorophenol

Chief complaint

Communication

Complete denture

Copal varnish

Crown

Curettage

Drain

Electric pulp test

Endontics

Equilibrate (ation)

Eugenol

Examination

Extraction (ed)

Fixed partial denture (bridge)

Fluoride

Fracture

Gutta percha

Health questionnaire reviewed

History

Mandibular

Maxillary

No significant finds

Objective

Operative

Oral cancer screening examination

Oral diagnosis

ANUG

A

ACNR

Am

Anes

BWX

CMCP

c c

Comm

CD

Cop

Cr

Cur

Drn

EPT

Endo

Equil

Eug

Exam

Ext

FPD

FI

Fx

GP

HQR

Hx

Man

Max

NSF

O

Oper

OCSE

OD

Oral Health Counseling O H C

Oral surgery O S

Panoramic radiograph Pano

Patient P t

Patient Informed of Examination Findings PTINF

and Treatment Plan

Perapical PA

Pericoronitis PCOR

Periodontal Screening and Record PSR

Periodontics Perio

P lan P

Plaque Control Instructions PCI

Porcelain Porc

Post Operative Treatment POT

Preparation Prep

Preventive dentistry PD

Prophylaxi Pro

Prosthodontics Pros

Removal partial denture RPD

Restoration(s) Rest

Return to clinic RTC

Subjective S

Scaled (ing) S

Surgical (ery) Scl

Suture (s) (d) su

Temporary Temp

Topical Top

Treatment (ed) TX

Zinc oxide and Eugenol ZOE

RECORDING DENTAL TREATMENT

When you are involved in recording dentaltreatment from an examination or charting treatmentthat has been completed, certain markings are chartedon the examination form you are using. The five formsthat will be discussed in this section are the ForensicExamination, located on the inside back cover of theNAVMED 6150/21-30, and Current Status Formlocated on the inside back cover section of NAVMED

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6150/21-30 underneath the record identifier for treatment. These four forms replace the old StandardPersonnel Reliability Program (if applicable). The last Form 603 and 603A (dental continuation). An examplethree forms are the Dental Exam Form (EZ603), of the old SF603 is shown in figures 2-4 and 2-5. AsDental Continuation Form (EZ603A), and the Report with any Navy form or instruction that becomesof Medical Examination (SF 88). obsolete, always use the current one available.

NOTE

Please be aware that some of the dental forms usedto record dental treatment will be changing in thefuture. The Bureau of Medicine and Surgery(BUMED) is now using the BUMED Approved EZ603(trial), EZ603A, Current Status Form and ForensicExamination Form to record dental examinations and

FORENSIC EXAMINATION

This form (fig. 2-6) replaces box 4 on the old SF603. It is intended that this form be completed onlyonce (usually at accession) during the member'smilitary career. If a replacement record is made, a newforensic exam will be completed. Next we will discusshow to complete the forensic exam form.

Figure 2-4.—Sample of old SF 603, front side.

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Figure 2-5.—Sample of old SF 603, back side.

Charting/Markings

The teeth are separated on the exam form tofacilitate illustrating supernumerary teeth, mixeddentition, and interproximal restorations. If arestoration exists interproximally with no occlusalcomponent, use the space to draw the restoration.When indicating fixed partial dentures, ignore thespaces. Draw the prosthesis and indicate thematerials and teeth involved in the Remarks sectionas usual.

Use the following symbols and notations tocomplete the top section of the Forensic Examination

form to record existing restorations, existing teeth,missing teeth, prosthetic appliances, and variation ofnormal conditions (non-disease). Use black ink withthe following symbols and notations. MANMEDchapter 6, also gives details on these symbols andnotations. Note: These same symbols are used for Box2 on the Current Status Form.

MISSING TEETH.—Draw a large "X" on theroot or roots of teeth not visible in the mouth. Figure2-7 illustrates teeth #6, #11, and #12 as missing orextracted teeth.

EDENTULOUS ARCH.—Make crossing lineseach running from the uppermost aspect of one third

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Figure 2-6.—Forensic Examination Form.

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molar to the lowermost aspect of the third molar on theopposite side. Figure 2-7 illustrates an edentulousmandibular arch.

EDENTULOUS MOUTH.—Inscribe crossinglines (fig. 2-8) one extending from the maxillary rightthird molar to the mandibular left third molar and theother line from the maxillary left third molar to themandibular right third molar.

PARTIALLY ERUPTED TOOTH.—In the Occlusal (O): Chart along the grooves on thediagram of the tooth, draw an arcing line through the occlusal surface (fig. 2-10, teeth #l, #2, and #5).

long axis. Figure 2-9 illustrates teeth #17 and #32 as

partially erupted.

AMALGAM RESTORATIONS.—In the

diagram of the tooth, draw an outline of the restoration

showing size, location, and shape, and block in solidly.

The following are different types of amalgam

restorations:

Figure 2-7.—Missing teeth and edentulous mandibular arch.

Figure 2-8.—Edentulous mouth.

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Figure 2-9.—Partially erupted teeth.

Figure 2-10.—Single surface amalgam restorations.

Double occlusal (O) (O): This restoration isoften referred to as "snake eyes." Chart along the twoseparate grooves on the occlusal surface (fig. 2-10,tooth #4).

Facial (F): Chart along the facial groove, in thefacial pit (fig. 2-10, tooth #14), or at the gingival marginof the facial surface (fig. 2-10, tooth #13).

Lingual (L): Chart these along the lingualgroove, in the lingual pit (fig. 2-10, tooth #14), or at thegingival margin on the lingual surface (fig. 2-10, tooth

#15). On anterior teeth, chart these restorations in thelingual pit (fig. 2-10, tooth #9).

Mesial-occlusal (MO): Chart by beginning atthe mesial surface and following the grooves on theocclusal surface to the central pit or groove (fig. 2-11,tooth #18). There can be two amalgam restorations(e.g., an MO and a DO) on the same tooth. In this casethe restoration will reach into the central groove, but notinclude the central pit (fig. 2-11, tooth #20). Rarely willa restoration cross the oblique ridge (fig. 2-11, tooth #2,#3, #14, and #15).

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Figure 2-11.—Two and three surface amalgam restorations.

Distal-occlusal (DO): Chart by beginning at thedistal surface, and follow the grooves on the occlusalsurface to the central pit or groove (fig. 2-11, tooth #28).

Occlusal-facial (OF): Chart starting at thecentral groove on the occlusal surface and down thefacial groove on the facial surface. Occlusal-facialrestorations are usually placed only on molars. On somemolars, all of the occlusal pits will be included in therestoration (fig. 2-11, tooth #17).

Occlusal-lingual (OL): Chart starting at thecentral groove on the occlusal surface and down thelingual groove on the lingual surface (fig. 2-11, tooth#31). Like (OF) amalgams, (OL) amalgams are usuallyplaced only on molars.

Mesial-occlusal-distal (MOD): Chart starting atthe mesial surface and follow the grooves on theocclusal surfaces to the distal surface (fig. 2-11, tooth#13 and #19). You can also think of a (MOD) amalgamrestoration as an (MO) and a (DO) amalgam restorationjoined together through the central groove on theocclusal surface.

Mesial-occlusal-distal-facial (MODF): Chartthe same way as a (MOD) amalgam restoration, butinclude the facial surface. The facial surface may becharted in several ways. It may be charted in the facialgroove (fig. 2-12, tooth #3), or it may be wrappedaround the mesial or distal facial surface (fig. 2-12,tooth #14). The (MODF) amalgam may include a partof the facial surface (fig. 2-12, tooth #1), or it mayinclude the entire facial surface (fig. 2-12, tooth #15).

Some (MODFs) include the coronal third of the facialsurface (fig. 2-12, tooth #16).

Mesial-occlusal-distal-lingual (MODL): Chartthe same way as a (MOD) amalgam restoration, butinclude the lingual surface. The lingual aspect may becharted in the lingual groove (fig. 2-12, tooth #18) or itmay wrap around the mesial and distal surfaces in thesame manner as that discussed for the (MODF). Figure2-12, tooth #30 and tooth #31, illustrates examples ofthe (MODL) restorations that include various portionsof the lingual surfaces.

Mes ia l -occ lusa l -d i s t a l - f ac ia l - l ingua l(MODFL): Chart by combining the (MODF) and(MODL) restorations. These restorations may includecarious portions of the facial and lingual surfaces.Figure 2-13 illustrates the different types of (MODFL)restorations.

NONMETALLIC PERMANENT RESTORA-TIONS.—Nonmetallic Permanent Restorationsinclude filled and unfilled resins, glass ionomercement and pit and fissure sealants. In the diagram ofthe tooth, draw an outline of the restorations showingsize, location, and shape. Do not block in. Thefollowing paragraphs explain how to chart nonmetallicrestorations.

Mesial (M) and distal (D): Chart these singlesurfaces on the mesial or the distal side of the facialsurface. Figure 2-14, illustrates a mesial restoration (M)on tooth #8, and a distal restoration (D) on tooth #9.

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Figure 2-12.—Four surface amalgam restorations.

Figure 2-13.—Five surface amalgam restorations.

Incisal (I): These restorations include the incisalsurface and/or one or more of the other surfaces (MI orDI). Tooth #10 in fig. 2-14, shows an (MI) restoration;tooth #7 in the same figure shows a (DI) restoration.

Facial (F): Chart along the gingival margin ofthe facial surface unless otherwise instructed by thedentist. Tooth #6 in fig. 2-14 shows a facial (F)restoration.

Lingual (L) on anterior teeth: You will usuallychart them in the lingual pit (fig. 2-14, tooth #11) or atthe gingival margin line of the tooth.

Nonmetallic restorations with two or moresurfaces: Chart these restorations as shown in themandibular arch in figure 2-14. Tooth #26 shows amesial-facial (MF) restoration; tooth #23, a distal-facial(DF) restoration; tooth #22, a mesial-facial-distal

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Figure 2-14.—Nonmetalic Restorations.

(MFD) restoration; tooth #25, a mesial-incisal-lingual(MIL) restoration; and tooth #24, a distal-incisal-lingual (DIL) restoration.

Porcelain, Acrylic Resin, Glass Ionomer,Artificial Crowns, Facings, and Pontics: Chart thesenonmetallic restorations by outlining all aspects of thecrown or facing as shown on tooth #27 in figure 2-14. Inthe "Remarks" section, indicate the material used.

GOLD RESTORATIONS.—Outline andinscribe horizontal lines within the outline. If made ofan alloy other than gold (chrome), the same charting

applies. Indicate in "Remarks" section on the ForensicExam form the type crown and metal used.

Figure 2-15 shows examples of gold restorations.Tooth #4 has a facial (F) gold restoration, tooth #7 hasa (DIL) gold restoration, and tooth #31 has a (MODFL)gold restoration.

To chart a full gold crown, outline each aspect ofthe crown, and then draw horizontal lines in theoutlined area (fig. 2-15, tooth #19). Gold crowns mayhave a tooth-colored facial surface made of acrylicresin or porcelain call "facings." These facings are

Figure 2-15.—Gold restorations and crowns.

2-15

inserted to give the restoration a natural appearance. Show partition at junction of materials and indicateTooth #5 and tooth #9 in figure 2-15 show full gold each type of material used. Inscribe diagonal parallelcrowns with nonmetallic facings. The nonmetallic lines to indicate gold. In the "Remarks" section,facing is only outlined. Where a full crown is not indicate each FPD type of material used (gold orneeded, a three quarter gold crown may be used as chrome). Figure 2-17 illustrates gold or chrome fixedshown on tooth #28 in fig. 2-15. partial dentures and what they look like charted.

COMBINATION RESTORATION.—Outlinethe area showing the approximate overall size,location, and shape; partition at junction of materialsused. Indicate each type of material used.

R E M O V A B L E P A R T I A L D E N T U R E S( R P D s ) A N D C O M P L E T E D E N T U R E S(CDs).—Mark the missing teeth as previouslydescribed. Place a horizontal line between the outlineof the teeth and the numerals designating teethreplaced by the CD or RPD (fig. 2-16). Note: On theForensic Examination form in the "Remarks" section,describe the CD or RPD, indicating whether they aremaxillary or mandibular and the type of restoration andmaterial used. An example of this would be Man RPD(acrylic, gold, or chrome-cobalt).

POST CROWN.—Chart the type of crownattached to the post. Outline each nonmetallic materialand show restorative metallic materials. Outlineapproximate size and position of post or posts. In the"Remarks" section, indicate the material used.

ROOT CANAL FILLING (RCF).—Chart thisspecialized filling by drawing a line(s) in the area ofthe root(s) where the root canal(s) would normally belocated. Teeth #3, #7, and #8 in figure 2-18 showexamples of root canal fillings. Note: Root canalfillings will always be accompanied by a restoration,usually a crown, amalgam, or composite restoration.

FIXED PARTIAL DENTURES (FPDs).—Outline each aspect, including abutments and pontics.

APICOECTOMY.—This procedure involves thesurgical removal of the apex of the tooth. Chart anapicoectomy by drawing a small triangle on the root ofthe tooth involved (fig. 2-18, tooth #11). Next chart theRCF on the root of the tooth beginning at the level of

Figure 2-16.—Removable partial dentures (RPDs).

2-16

Figure 2-17.—Gold or chrome fixed partial dentures (FPDs).

Figure 2-18.—Root canal fillings (RCFs) and apicoectomy.

the root amputation where the apicoectomy has beenperformed. The dentist will read the patient'sradiograph to determine the level of the rootamputation. Also note the (L) amalgam restoration ontooth #11.

DECIDUOUS TEETH.—Occasionally, adeciduous tooth will be retained in the adult mouth.Circle the appropriate alphabetical designation on theForensic and Current Status forms if deciduous teethare present. Figure 2-19 illustrates a deciduous tooth# l l .

SUPERNUMERARY TEETH.—These areextra teeth other than the normal 32 teeth that arepresent in the mouth. To chart a supernumerary tooth,draw an outline of the tooth in its approximate location.Then insert an "S" in the proper location on the toothnumber line as shown in figure 2-19.

DRIFTED TEETH.—To chart a drifted tooth,draw an arrow from the number of the drifted tooth asshown in figure 2-19 (teeth #19, #20, #32 and #31).The point of the arrow should indicate the approximateposition to which the tooth has drifted. Drifting

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Figure 2-19.—Deciduous, supernumerary, and drifted teeth.

usually occurs when teeth move toward the space of anextracted tooth.

TEMPORARY RESTORATIONS.—In the

diagram of the tooth, draw an outline of the restorationshowing size, location, and shape. If possible, describethe material in the remarks section.

Remarks Section

Use this section to indicate the restorative

materials and to differentiate between sealants,composites, and temporaries.

Soft Tissue Remarks Section

This is just a partial list of some of the more

common non-pathologic findings to facilitatecharting. For each condition, indicate approximatesize or extent and location. Leave blank if a conditiondoes not exist.

Occlusion Section

The examining dentist will tell you what Angle'sclass the patient has. The three classes are I, -11, or III.Each side of the patient's mouth may be different.Record the results in the space provided.

In the overjet and overbite section of occlusion, thedentist will let you know in millimeters the extent ofthe abnormality. Leave blank if normal.

In the crossbite section, the dentist will let youknow the teeth involved to be written in the spaceprovided.

The dentist will use the Remarks section of theocclusion section to record any other occlusalcondition not listed above.

Hard Tissue Remarks Section

exist.

This is just a partial list of some of the morecommon non-pathologic findings to facilitatecharting. Leave section blank if the condition does not

Intrinsic staining-Indicate teeth involved.Check tetracycline, if appropriate.

Tori—Indicate location and approximate size ofprojection.

Rotated teeth—Indicate teeth involved andapproximate number of degrees to the nearest 45degrees.

Malposed Teeth—Indicate teeth involved andwhether facio- or linguo-version.

Other—Use this space when noting other hardtissue conditions not listed above.

Examining Dentist Name Stamp andSignature Sections

Use the examining dentist's name stamp to markthis section and ensure the signature line is signed.

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CURRENT STATUS FORM Current Status form contains 4 boxes that explains the

Figure 2-20.—Current Status Form.

This form (fig. 2-20) will last the entire service

career of the patient. It is placed in the NAVMED

instructions for charting symbols used in boxes 1 and 2.

Box 1

6150/21-30 in the same way the Personnel Reliability

Program warning form is so that it may be folded up

when not in use. If a new Current Status form is ever

Box 1, Accession and Subsequent Diseases andAbnormalities, replaces box 5 and box 9 (old box 16)on the SF 603/603A.

needed, the information from the previous forms must

be transferred to the new form. The form is dated at

the top when placed in use by the initial examiner and

All carious lesions, indications for extraction,indications for root canal treatment, and periradicularlesions that the examining dentist recommends for the

dated again when replaced by the final provider. The patient are drawn in pencil using the charting symbols

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listed in this section. When the indicated treatment iscompleted, the pencil entry is erased.

Charting Symbols (Box 1)

Use the following instructions for charting in thesection, Accession and Subsequent Diseases andAbnormalities Section (Box 1). Make sure you donot enter these symbols in Box 2, Missing Teeth atTime of Accession and Treatments CompletedAfter Accession. Entering these symbols in thewrong area would prevent differentiation betweenthe caries and the restorations. Figure 2-21illustrates charting symbols for Box 1.

CARIES.—On the diagram of the tooth affected,draw an outline of the carious portion, showingapproximate size, location, and shape; block in solidly.

DEFECTIVE RESTORATION.—Outline thedefective restoration, including the carious orotherwise defective area, and block in solidly.

UNERUPTED TOOTH.—Outline all aspects ofthe tooth with a single oval. This includes impactedteeth.

INCLINATION (TILT) OF IMPACTEDTEETH.—Draw an arrow of the facial aspect of the

crown portion of the diagram that indicates thedirection of the long axis of the tooth.

EXTRACTION (REMOVAL) INDICATED.—Drawtwo parallel vertical lines through all aspects of thetooth and roots involved. This applies also tounerupted teeth when removal is necessary.

RETAINED ROOT.—Draw a horizontal line onthe root showing the level of retention. Place an "X" onthe missing area. Draw two parallel lines in thedirection of the long axis of the root through the partthat is retained if extraction is indicated.

FRACTURED TOOTH.—Trace a jaggedfracture line in the relative position on the crown orroots affected.

PERIAPICAL RADIOLUCENCY.—Outlineapproximate size, form, and location of the periapicalradiolucencies, such as an abscess or cyst.

FISTULA.—Draw a straight line from theinvolved area, ending in a small circle in a position onthe chart corresponding to the location of the tractorifice (opening) in the mouth.

UNDERFILLED ROOT CANAL.—Draw avertical line from the crown toward the apex showingthe extent of the filling.

Figure 2-21.—Charting symbols for Box 1, Accession and Subsequent Diseases and Abnormalities.

2-20

RESORPTION OF ROOT.—Draw an even lineon the root showing the extent of resorption of the root.

P E R I O D O N T I T I S A N D A L V E O L A RRESORPTION. —Indicate the extent of gingivalrecession by drawing a continuous line across theroots to approximate the extent of involvement. Drawanother continuous line at the proper level across theroots of the teeth to indicate the extent of alveolarresorption. Base this finding on the dentist’s clinicaland radiographic findings.

Box 2

Box 2, Missing Teeth at Time Of Accession andTreatments Completed After Accession replaces box 8(old box 15) on the SF 603/603A and functions in thesame way with the following exceptions:

The information is cumulative on this formthroughout the patient’s military career.

Missing teeth from the accession exam are alsoincluded in this box. By including thisinformation, the SF 88, box 18 (old box 44) canbe completed by looking at boxes 1 and 2 of theCurrent Status Form.

All extractions, restorations and root canaltreatment completed during the patient’s service careerare entered using the symbols mentioned previously inthis chapter under designations, abbreviations, andcharting.

When indicating fixed partial dentures, ignore thespaces on the form in between the teeth and draw theprosthesis on each tooth as usual. Only use black inkto make entries in box 2.

Charting Symbols (Box 2)

Use the same instructions and symbols from theForensic Examination section for charting Missingteeth at Time of Accession and Treatments Completedafter Accession (Box 2). When charting existingrestorations, draw the restoration and show theapproximate size, location, and shape in the diagram ofthe tooth. Identify missing teeth and restorativematerials as previously shown in the ForensicExamination section (Charting/Markings). Note: Noremarks are made on the Current Status form toindicate materials used.

Box 3

Box 3, Medical Alert, is readily seen by allclinicians when opening the record. If a medical alertexists, the word "ALERT" is written or stamped inlarge red letters with a brief explanation following(i.e., ALLERGIC TO PENICILLIN). The use of redink stamps is encouraged.

Box 4

Box 4 is used to record the patient's last name, firstname, middle initial, and patient/sponsor SocialSecurity Number.

DENTAL EXAM FORM

The Dental Examination form (EZ603) (fig. 2-22),is a new form that replaces part of the front of the oldSF 603 and all of the various SOAP (subjective,objective, assessment, and plan) formats. It is intendedto be used on the initial, subsequent periodic, annual,recall, SF 88, and separation exams. It is not intendedfor emergency or specialty consult exams. All entriesare made in black ink except as noted. During thedental exam, the examining dentist may direct you tofill out the EZ603 and associated boxes on the formwith information. The front page of the Dental ExamForm contains the "S," "O," "A," and "P" sections ofthe exam that are briefly discussed next.

Subjective Section (S:)—This section of theform is used to fill out the reason for theexamination and the patient's chief complaint.

Objective Section (O:)—This section isgenerally meant to record findings and not adiagnosis. The major exception is the cariessection where the findings and diagnosis are oneand the same.

Assessment Section (A:)—This section isgenerally used by the examiner to make adiagnosis.

Plan Section (P:)—This sect ion is the"Treatment Plan" for the patient.

The EZ603 is a new trial form and may be changedin the future. Instructions for the completion of theEZ603 can be found in MANMED, chapter 6, orcurrent BUMED instructions.

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Figure 2-22.—Dental Exam Form, BUMED-approved EZ603.

INSTRUCTIONS FOR COMPLETINGTHE BACK OF THE EZ603

The reverse side of the EZ603 (which is blank) isprovided for recording the narrative commentsassociated with the dental exam and relatedconsultation. Commands are authorized to overprintthis section with command specific formats that willfacilitate the completion of the dental examination.

For placement in the Dental Record, the EZ603 isplaced with the Plan or "P" side facing up. It is locatedon top of any accompanying EZ603As and under theCurrent Status Form.

INSTRUCTIONS FOR COMPLETINGTHE EZ603A

This form (fig. 2-23) functions the same as the oldSF603 (side 2) and SF603A with the exception of nopictographs of the teeth. Record the completion of alldental treatment such as the treatment plan, dentalemergencies, results from Report of MedicalExamination (SF 88), and any other narrative dentalfindings on the EZ603A.

An additional column has been added on the farleft side to indicate the tooth number (s) of thetreatment provided on that date. This will facilitate

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Figure 2-23.—Dental Treatment Form (EZ603A).

piecing together a treatment history of a particulartooth.

A medical alert, if present, is written in red ink atthe top of the EZ603A. All entries, except for themedical alert, are made per MANMED chapter 6,Section 13 through 15, in black ink. Complete thepatient identification box as indicated at the bottomportion of the EZ603A.

REPORT OF MEDICAL EXAMINATION,(SF 88)

Frequently, you will have patients needing a dentalexamination in conjunction with a medical physical.

The SF 88 (rev. 10-94) (figs. 2-24 (front) and 2-25(back)) is used to record the findings of a dentalexamination. Please note that this form replaces theold SF 88 (rev. 10-75). Only boxes 18 (old box 44), 43(old box 74), and 50 (old box 81) will require dentalentries. Although this form is self-explanatory andquite simple to complete, it is important that the entriesyou make are neat and accurate in every detail. Next,boxes 18, 43, and 50 of the SF 88 are discussed.

Box 18

Chart the conditions noted by the dentist. Thecharting symbols are printed on the upper portion of

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Figure 2-24.—Report of Medical Examination, SF 88, (front) Box 18.

box 18. Use these symbols to chart the lower portion ofthis box. Box 18 also contains space for the dentist's"Remarks and Additional Dental Defects andDiseases." In this space, type, print, or stamp the typeof dental exam, dental classification, and qualified"YES" or "NO."

Box 43

Include here a summary of the patient's dentaldefects and the dentist's diagnosis. Since the summary

refers to the items noted in box 18 (the dental section ofthe report), mark in the summary #18 and list defectsand diagnosis.

Box 50

Type, print or stamp the examining dentist's name,rank, DC, and USN (or USNR) or civilian title(DDS/DMD) if a contract dentist performs theexamination. A dentist or physician signs his or hersignature in box 50.

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Figure 2-25.—Report of Medical Examination, SF 88, (back) boxes 43 and 50.

ADDITIONAL DENTAL TREATMENT and dental departments use the SF 513 (fig. 2-26) toFORMS refer patients from one DTF/MTF, or department to

Two other forms may be associated with dentaltreatment. These forms are the Consultation Sheet, SF513, and the Reserve Dental Assessment andCertif ication, NAVMED 6600/12, which arediscussed next.

another. Please note that SF 513 refers patients with

both dental and medical conditions needing a second

opinion or a referral to a specialist for further

evaluation or treatment. To assist you in filling out this

form, make the following entries on the SF 513:

CONSULTATION SHEET, SF 513

Dental Treatment Facilities (DTFs), MedicalTreatment Facilities (MTFs), and shipboard medical

To: Enter the name of the DTF/MTF, or depart-red.ment to which the patient is being refer

From: The name of the requesting facility.

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Figure 2-26.—Consultation Sheet, SF 513.

Date of Request: The date the Consultation

Sheet is prepared.

Reason for Request: The reason as stated by thedentist or requester.

Provisional Diagnosis: The diagnosis as stated

by the dentist or requester.

Doctor's Signature: Type, print, or stamp thename, rank, title of the dentist or requester with

his or her signature in this space.

Place of Consultation: Check "bedside" or "OnCall." Also mark the next box as "Routine,""Today," "72 Hours," or "Emergency."

Consultation Report: Leave blank. Thissection will be filled in by the person receivingthe form.

Patient's Identification: The patient's name (last,first, and middle initial), branch of service andstatus, rank/rate, family prefix code, and socialsecurity number, and the activity to which thepatient is assigned.

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RESERVE DENTAL ASSESSMENT ANDCERTIFICATION, NAVMED 6600/12

Voluntary Training Unit (VTU) or SelectedReserve (SELRES) personnel may have thisadditional form included in their dental records. UseNAVMED 6600/12 in conjunction with the NavalReserve T-1 or T-2 dental examination that isperformed every 5 years or with any required physicalexamination. Instructions for completion of theNAVMED 6600/12 is found in MANMED, chapter 6.

PATIENT DISMISSAL

Once the examination is completed, return thepatient’s dental prosthesis if it was removed for theexam. The dentist may have instructions for the

patient; for example, information regardingmedications or future appointments. Make sure thatthe patient understands the instructions given by thedentist. Remove the patient napkin from the patientand place it over the contaminated instruments.

Push the dental operating light and the brackettable out of the way so the patient will not bump againstthem. Return the dental chair to its lowest uprightposition, raise the arm of the chair and assist the patientfrom the chair.

Direct the patient to the front desk to make futureappointments if needed. Remove all instruments andprepare the DTR for the next patient. Follow theinfection control, sterilization, and disinfectionprocedures outlined in Dental Technician, Volume 1,chapters 9 and 10.

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CHAPTER 3

PREVENTIVE DENTISTRY

INTRODUCTION

The goal of preventive dentistry is to assist thepatient in either establishing control of his or her dentaldisease or in continuing to maintain good oral health.Preventive dentistry includes all clinical tests,treatments, and patient education for the purposeof preventing oral disease and supporting theeffectiveness of treatment aimed at caries andperiodontitis. All patients will receive a carefulassessment of their oral health needs and be providedwith an individualized preventive dentistry treatmentplan.

PREVENTIVE DENTISTRYTECHNICIAN

Each dental treatment facility has an appointedpreventive dentistry officer responsible for theformulation, supervision, and execution of allaspects of the preventive dentistry program as perSECNAVINST 6600.5. For you to perform preventivedentistry procedures, you should elect to qualify as anexpanded function preventive dentistry technician at yourcommand. Details for this program can be found inBUMEDINST 6600.13. Some of the duties of apreventive dentistry technician are as follows:

use of home care devicesDemonstrates proper patient instruction in the

Sharpens and demonstrates proper care ofperiodontal instruments

Delivers pre-operative oral antimicrobialrinses

Places pit and fissure sealants

Applies topical anticariogenic agents

Performs oral prophylaxis

Provides nutrition/diet counseling

Performs supragingival scalings with hand andsonic instruments

Completes a thorough dental health questionnairereview

ORAL PROPHYLAXIS

The term prophylaxis means prevention ofdisease. When you apply its broadest interpretation tothe oral cavity, it includes all measures to prevent oraldisease. For our purposes, we define oral prophylaxisas the clinical procedures that you perform for yourpatients. Our discussion will include evaluation ofrecords, the seating of the patient, instruments,examinations, and contraindications to prophylaxis.We will begin with the evaluation of the patient'sdental health record.

PREPARATION FOR ORALPROPHYLAXIS

Before the patient enters the dental treatment room(DTR), evaluate his or her dental record forcompleteness. The folder should contain the patient'sdental records, current radiographs, a current dentalhealth questionnaire and any other applicable formsdiscussed in Dental Technician, Volume 1,NAVEDTRA 12572, chapter 2, and chapter 2 of thismanual. Check the past medical and dental history ofthe patient. Check the recommendations that weremade during previous oral prophylaxis appointmentsand the recent dental examinations. If the patient hashad radiographs taken since the previous oralprophylaxis, evaluate them for subgingival calculusand restoration margin overhangs. Subgingivalcalculus can appear on a radiograph as a "spur" ordeposit between the teeth, below the gingival margin.

NOTE: Subgingival calculus and overhangscan only be removed by a dental officer ordental hygienist.

If you find any subgingival calculus during thepatient examination or treatment, contact a dentalofficer or hygienist who will remove it either duringyour appointment with the patient or at a later time. Apreventive dentistry technician should only treatpatients with supragingival calculus who arescheduled for routine oral prophylaxis. Patients withsubgingival calculus will be appointed with a dentalofficer or dental hygienist. The dental treatment planwill indicate who will treat the patient to ensure properscheduling.

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CONTRAINDICATIONS TOPROPHYLAXIS

Evaluate the medical history of dental patientsbefore treatment begins. NAVMED Form 6600/3 willbe completed to find out whether there are any medicalproblems that can affect dental treatment. Somepatients have medical conditions, such as a heartmurmur, that require antibiotic treatment 1 hour beforeyou can treat them. If the medical history indicates thepatient has or had a heart murmur, ask the patient if heor she has taken any antibiotic medicine.

NOTE: If any questions on the NAVMED6600/3 are answered "yes," it is of the utmostimportance that you discuss the patient’shistory with a dental officer before renderingtreatment.

PATIENT AND OPERATORPOSITIONING

Correct operator and patient positioning helps toaccomplish the following:

Prevents operator and patient fatigue anddiscomfort

Permits the operator to gain a clear view of thetooth being worked on

Allows easy access of instruments to the teeth

Saves time

Patient Positioning

Position the back of the patient's chair at about a15° angle (slightly raised above the parallel position)to the floor (fig. 3-1).

The patient's heels should be even or slightlyhigher than the head. The top of the patient's head mustbe even with the end of the headrest for you to see andreach the patient's mouth. If possible, position thebracket tray out of the patient's direct vision. Ask thepatient if he or she is in a comfortable position.

Operator Positioning

To properly position yourself in the seatedoperator position, adjust the chair so that you arecomfortable and your posture is correct. To maintaingood working posture (fig. 3-2), position your feet flaton the floor, thighs parallel to the floor, back and headstraight, and arms at waist level. Keep your bodyweight evenly distributed.

Figure 3-2.—Seated operator position.

Figure 3-1.—Positioning of the patient.

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Your unit light is kept at arms length above or infront of the patient. The light should be easy to reachbut not near the patient's or operator's head.Illumination of the treatment area becomes moredifficult when the light is positioned too close to thepatient. In addition the light generates a large amountof heat. Direct the unit light from above the patient asshown in figure 3-3.

The position of the bracket table should be lowenough to permit a clear view of the instruments. Itshould also be a reasonable distance above and to theside of the patient.

The patient's open mouth should be level with yourwaist. This will enable you to reach the patient's mouthwhile maintaining your arms at waist level. Formandibular instrumentation, the patient will have hisor her mouth open in a chin-down position. Positionyour legs under the back of the chair. The back of thedental chair should touch the top of your legs, or youmay straddle the back of the chair with your legs.

Now you are ready to learn how to position yourselfaround your patient in relation to the treatment areasof the mouth. Operating positions for right-handedand left-handed technicians are usually identified inrelation to a 12-hour clock (figs. 3-4 and 3-5).

Figure 3-4.—Operating positions-right-handed operator.

As you try various positions, notice how theyafford you a clear view of the treatment area. You willnot be able to obtain a clear view of the teeth surfaces inthe mouth through operator and patient positioning

Figure 3-3.—Unit light placement.

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Figure 3-5.—Operating positions-left-handed operator.

alone. The use of the mouth mirror will assist you toobtain a complete view.

Plaque is nearly transparent and difficult to seewithout the use of a stain or disclosing agent tohighlight its presence. These agents color the plaque,but they do not color clean tooth surfaces. Thecoloring agent used in disclosing is a harmless red fooddye and comes in the form of tablets or liquid. Followthe manufacturer's instructions for use. After yourinitial examination of the patient, apply a disclosingagent to reveal the presence of plaque before theprophylaxis procedures. This will help you and thepatient identify what must be cleaned and will assist inpatient education.

TYPES, USES, AND MAINTENANCE OFPERIODONTAL EQUIPMENT

The ultrasonic scaler, air polishing unit, and sonicscaler were designed for use in oral prophylaxis andother periodontal procedures.

WARNING

Before operating any equipment, ensure youare familiar with its use, operation, and safetyprecautions.

SCREENING EXAMINATIONULTRASONIC SCALER

Before you begin any scaling procedures, make athorough appraisal of the condition of the patient’smouth. This examination serves three purposes:

Determines the needs of the patient

Determines the sequence in which these needsmust be met

Provides you with useful information forconducting the dental health counseling

The screening examination has two phases:

Observation of the entire oral mucosa

Examination of the teeth and gingival tissues

Look for ulcers or sores on the lips, skin, orintraoral mucosa. These may be the result of viral orother infections, which could preclude your treatmentof the patient. You can also ask the patient if he or shehas any sensitive or painful teeth or areas in the mouthabout which you should know. If you see somethingduring your examination that you do not recognize as anormal feature of the anatomy, check with a dentalofficer before proceding.

The ultrasonic scaler converts electrical energyinto 30,000 microscopically small mechanical strokesper second. The strokes are transmitted to an insert tip.Combined with a water spray and a light touch, theactivated tip rapidly and gently dislodges plaque,calculus, and stain from the teeth. As you can imagine,the ultrasonic unit can generate a great amount of heat.For this reason, water is kept running through the entireunit and expelled from the working end of theinstrument. Water aids to cool the tip of the instrumentand the tooth structure. The water also serves to washaway debris. The vibratory motion of the tip transmitsmechanical energy to water that creates powerfulbursts of collapsing bubbles called cavitation.Cavitation aids in the mechanical removal of plaqueand calculus by the vibrating tip.

Components

The four major components of the unit are anelectronic generator, a hand piece assembly, a set ofinterchangeable inserts, and a foot-controlled switch.A picture of an ultrasonic scaler unit is shown in

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figure 3-6. Follow the manufacturer's instructions onsetup, adjusting water flow, ultrasonic tuning, andultrasonic power. Some units are tuned automaticallywhile others require manual tuning.

ELECTRONIC GENERATOR.—The electronicgenerator produces the power required to activate thehandpiece. The three controls located on the frontpanel of an automatically tuned ultrasonic unit are theON/OFF indica tor , POWER ADJUSTMENTCONTROL, and a WATER ADJUSTMENTCONTROL. A manually tuned ultrasonic unit willalso have a TUNING ADJUSTMENT CONTROL.

HANDPIECE AND CABLE ASSEMBLY.—This assembly consists of a handpiece into whichinterchangeable scaling inserts are placed. A cableconnects the handpiece to the generator. To place an

Figure 3-6.—Ultrasonic scaler unit.

Figure 3-7.—Placement of the insert into the handpiece.

insert into the handpiece, first lubricate the O-ring withwater. Then hold the handpiece with the open endupright over a sink or suitable basin. Step on the footswitch to turn on the unit and flood the handpiecechamber with water. Stop flooding when you see thewater has reached a level halfway up the handpiece.Push the insert into the open end of the handpiece witha twisting motion (fig. 3-7); a small amount of watermay be displaced by the insert stack and may spill out.Check to see if the insert is fully seated. With the insertin place, hold the handpiece in an upright position.Activate the insert and bleed off any air trapped duringhandpiece insertion. Allow the water to run from thehandpiece for a few seconds until it flows withoutspurting. Repeat this procedure each time an insert isplaced into the handpiece. Trapped air does notinterfere with the handpiece operation, but can causeexcessive heating of the instrument.

INTERCHANGEABLE INSERTS.—A set ofinterchangeable inserts facilitates access to all areas ofthe mouth. The components of an insert include theinsert tip, water outlet, plastic grip, O-ring, connectingbody, and the magnetostrictive stack (fig. 3-8). Thewater outlet delivers preheated water along the entireworking length of the tip. The O-ring acts as a waterseal when the insert is placed into the open end of thehandpiece. A connecting body transmits motion fromthe stack to insert tip. The magnetostrictive stackconverts electrical power supplied to the handpieceinto mechanical vibrations to activate the insert tip.

FOOT CONTROLLED SWITCH.—Thehandpiece is activated by a foot-operated on/offswitch. When the foot pedal is held down, thehandpiece is activated and water flows. Both thehandpiece and water flow are shut off when the pedal isreleased.

Water Supply

Attached to the ultrasonic scaling unit is a watersupply hose. The free end of the hose attaches to a

Figure 3-8.—Components of the interchangeable inserts.

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water connection on the dental unit. The water supplypressure should range from a minimum of 25 psi to amaximum of 60 psi. Water pressure outside of thisrange can cause the equipment to malfunction. Referto the manufacturer's instructions for specificinformation.

Flush the waterline daily before use to reduce thebacteria that accumulates overnight. Set the waterflow to maximum and depress the foot switch for 1minute without an insert in the handpiece. Before useon each patient, flush the waterline for 30 seconds.

Ultrasonic Tips and Techniques

A wide variety of inserts are available for use withthe ultrasonic scaler. Each insert is designed for aspecific use. A power level is recommended by themanufacturer for each insert.

Tip selection is based on the type, location, andamount of calculus deposits present. Larger tips areeffective in removing heavy supragingival calculusdeposits and stains, where smaller tips used by adentist or hvgienist are similar in design to a scaler andcan be used subgingivally. The tips should be dull sothey will not damage the tooth and root surface. Thevarious tips and their uses are as follows:

Beaver-tail ultrasonic tip (fig. 3-9)—Used on thelingual and facial posterior surfaces to remove veryheavy, supragingival deposits. Use light pressure withan erasing motion for stain removal and overlappingstrokes for calculus removal. Avoid using the sides orface of this insert. Use the high power level with thisinsert.

Figure 3-9.—Beaver-tail ultrasonic tip.

Chisel ultrasonic tip (fig. 3-10)—Used forremoving supragingival calculus on anterior teeth.Place the tip against the proximal tooth surface and use ahorizontal stroke to remove the calculus. Set the powerlevel on high for this insert.

Universal ultrasonic tip (fig. 3-11)—The mostcommonly used tip for supra and subgingival calculusdeposits in all areas. The universal tip is ideally suitedfor finishing after completing heavier scalingprocedures. Use the sides of the insert with only lightpressure, and push or pull strokes. Set the power levelat high for this insert.

Periodontal probe ultrasonic tip (fig. 3-12)—Usedto remove subgingival calculus. Used by dentist ordental hygienist with a horizontal or vertical stroke. Setthe Dower level on medium for this insert.

Figure 3-10.—Chisel ultrasonic tip.

Figure 3-11.—Universal ultrasonic tip.

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Figure 3-12.—Periodontal probe ultrasonic tip.

Before starting ultrasonic scaling, take time toexplain the procedure to your patient. The noise, waterspray, and vibratory sensation produced by theultrasonic scaler may frighten the patient if no warningis given. Place a plastic drape on your patient inaddition to the patient towel to prevent clothing frombecoming wet. If possible, have the patient rinse for 30seconds with an antimicrobial mouthwash beforetreatment to reduce aerosol pathogens. The amount ofwater that will accumulate in the patient's mouth willnecessitate the use of a saliva ejector. Ask your patientto hold the evacuation tip if necessary.

Hold the ultrasonic handpiece in a modified pengrasp (discussed later in this chapter) with the end ofthe hose tucked in the palm of your hand. This preventsthe hose from weighing down the handpiece. Establisha fulcrum (discussed later) on a tooth in the same archas close as possible to the tooth you are treating. Theworking end of the instrument tip should be adapted toa 10° to 15° angle to the long axis of the tooth. Use thelateral surfaces, face, and back of the instrument tip forscaling. The toe or tip of the working end should neverbe used to scale.

Patient Sensitivity

If the patient reports tooth sensitivity duringultrasonic scaling, several possibilities exist. First, becertain the insert tip is at a 10° to 15° angle to the toothsurface. You can increase the speed of tip movementover hypersensitive areas to alleviate discomfort. Achange in the motion of the insert tip from vertical tohorizontal, or vice versa, sometimes helps diminish

sensitivity. It may be necessary to lighten your fingerpressure on the handpiece, especially on exposeddentin. If sensitivity persists, decrease the powersetting.

NOTE: Incorrect adaptation of the instrumentto the tooth will cause pain to the patient anddamage to the tooth.

It is very important to understand that theinstrument tip must be in direct contact with thecalculus deposit to be effective. Use light, rapidstrokes, keeping the tip moving at all times to avoidheat build up or tooth damage.

Level I Maintenance

No special maintenance is required; however,several precautionary measures should be followed:

Do not place the unit on or next to a heat sources ince i t cou ld damage the e l ec t ron iccomponents.

Do not keep the unit in a tightly confined spaceor corner. Keep it where a normal amount of airwill circulate freely on all sides of the unit.

The unit should not be used when the patient oroperator of the unit is wearing a cardiacpacemaker.

You may experience some difficulties with theunit that requires minor adjustments. For example, thehandpiece may heat up if there is insufficient waterflow or air is trapped in the handpiece. Water flowrequires adjustment if the spray from the insert doesnot properly cover the area of the activated insert tip.Water leaks from the handpiece during operationgenerally indicate that the O-ring on the insert is wornand requires replacement. Always consult themanufacturer’s instructions for the causes andcorrective measures for other problems.

AIR POLISHING UNIT

The air polishing unit (fig. 3-13) uses air and waterto project a controlled stream of specially processedsodium bicarbonate. It removes gross extrinsic stain,plaque, and soft debris from all exposed surfaces of thetooth enamel. It polishes and cleans tooth surfaces,pits, and fissures. Some patients prefer this method ofpolishing, which reduces the sense of pressure and heatassociated with use of a rubber cup and pumice. Airpolishing is ideal for polishing teeth to which

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Figure 3-13.—Air polishing unit.

orthodontic bands and brackets are applied. Airpolishing of enamel also increases resin bond strengthwhen used before acid etching for sealants and otherprocedures.

Components

The three major components of the unit are the airpolishing delivery system, foot-controlled switch, andhandpiece assembly. Some newer models combine the airpolishing and ultrasonic systems. In such units, additionalcomponents and controls exist because the units arecombined (fig. 3-14). The combination handpieceassembly has separate openings to accommodate thescaling and polishing inserts (fig. 3-15). The operationand maintenance of the combined unit are the same asthe two independent units.

Technique

Keep the handpiece tip approximately 4mm to5mm from the tooth surface being cleaned. Center thespray on the middle one-third of the tooth and use aconstant circular motion. The edge of the spray will

Figure 3-14.—Combined ultrasonic scaler and air polishingunit.

Figure 3-15.—Handpiece assembly of an air polishing unit.

clean the tooth surface near the gingiva. Theangulation of the handpiece tip to the surface variesaccording to the different locations of the teeth.

On the facial and lingual surfaces of all posteriorteeth, direct the handpiece slightly distally at an 80°angle toward the gingiva (fig. 3-16). On the facial andlingual surfaces of all anterior teeth, direct thehandpiece at a 60° angle toward the gingiva (fig. 3-16).For all occlusal surfaces, direct the handpiece at a 90°angle to the surface.

Precautions and Contraindications

You must be concerned with several precautionsand contraindications to the use of the air polishingsystem. Avoid direct contact of the cleaning jet withsoft tissue. This could seriously and unnecessarilyharm mucosa or gingiva. To preclude possible softtissue emphysema or air embolism effects, never directthe tip into the sulcus. Sodium bicarbonate airpolishing of highly polished metal restorations willleave a matte (dull) finish. Avoid prolonged use of thissystem on cementum or dentin. Consult with a dentist

Figure 3-16.—Angulation of the air polishing handpiece tip onfacial and lingual surfaces of anterior and posterior teeth.

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before air polishing teeth in patients with severerespiratory illness or on a restricted sodium diet.Patients wearing contact lenses must remove thembefore you use this polishing system.

Level I Maintenance

The waterline should be flushed daily before usefor 60 seconds to reduce any bacteria that accumulatesin the line overnight. The handpiece should be flushedfor 30 seconds before use between patients. At the endof the day, remove and empty the powder chamber.The cleaning powder must be kept dry and stored in aplace that does not exceed 95°F. For additionalinformation on maintenance of the powder chamberand other procedures, refer to the manufacturer'sinstructions.

SONIC SCALER

The sonic scaler is an air-powered, mechanicalscaler that runs at sonic frequency and uses acontrolled water spray. It removes large calculusdeposits and stains from teeth.

Components

The sonic scaler consists of the scaler handpieceand three types of tips (fig. 3-17). Both the tips andhandpiece can be sterilized. The handpiece attaches tothe hoses on the dental unit with a swivel attachmentcoupling. Air and water pressure are controlled byusing the air and water control valves on the dentalunit. The three type tips and their uses are as follows:

Universal tip—Used for all surfaces to removemedium and heavy calculus deposits

You can prevent fogging of the mirror by:

Figure 3-17.—Sonic scaler handpiece and tips. Left to right: Requesting the patient breathe through the nose,Universal, Perio, and Sickle tip. rather than the mouth

patients, and to remove light to medium depositsof calculus

Perio tip—Breaks up heavy calculus and isrecommended for supragingival scaling of thelingual mandibular incisors

Sickle tip—Recommended for sensitive

Technique

Lightly apply the vibrating tip to the tooth'ssurface using a back and forth brush stroke todislodge the calculus deposits. The handpiecedirects a continuous water spray to cool the tip andtooth to prevent overheating. Avoid placing thescaler tip directly on the enamel since this will causepitting.

Level I Maintenance

Follow the manufacturer's instructions forinstrument sterilization and other maintenancerequirements. As with other devices supplied withwater from the dental unit, flush the sonic scalerwaterline for 60 seconds at the beginning of theworkday and for 30 seconds between patients.

PERIODONTAL SCALINGINSTRUMENTS

Periodontal hand scalers are important inremoving calculus. These instruments are discussed inchapter 6, "Periodontal Assistance." In addition tohand scaling instruments, part of your preventivedentistry setup will include a mouth mirror and anexplorer.

MOUTH MIRROR

The mouth mirror permits examination of toothsurfaces in areas of the mouth that cannot be vieweddirectly. The mouth mirror is also useful as a retractorof the patient's tongue and cheeks.

Avoid causing discomfort to the patient when youare using the mouth mirror. Do not use excessivepressure on the handle or shank against the patient'slips or the comer of the mouth. Do not press the edge ofthe mirror into the gingiva. Since some teeth aresensitive to metal, do not touch the teeth with themirror when you are inserting it into or removing itfrom the mouth.

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Using a special defogging solution

Warming the mirror by holding it against the

patient's buccal mucosa

Heating the mirror under warm running water

Hold the mirror with a modified pen grasp and usea finger rest close to the area being viewed.

EXPLORER

The explorer is used for tactile examination of theteeth. It is excellent for detection of calculus. Use itover the entire dentition to ensure all detectablecalculus and stains have been removed following anoral prophylaxis. Otherwise, it is likely you will leavesome calculus deposits or stains on the teeth.

INSTRUMENT GRASP

A correct instrument grasp has a direct bearingupon your ability to manipulate instruments. There arethree instrument grasps that you may use incombination with a finger rest during oral prophylaxisprocedures. We will describe them in the followingparagraphs.

PEN GRASP

finger supports the instrument from underneath. Thisis a favorite grasp when using the mouth mirror.

With the pen grasp, hold the instrument the wayyou would hold a pen when writing. Grasp the handlewith your thumb and first finger while your middle

MODIFIED PEN GRASP

With the modified pen grasp, hold the instrumentin basically the same way as in the pen grasp, exceptthat the fleshy part of your middle finger rests lightlyon the shank of the instrument (fig. 3-18). This fingeris used to feel the shank vibrate when the instrument'sworking end rubs over a rough surface. The middlefinger also helps to guide the instrument. The ringfinger is used to stabilize the hand in the patient'smouth. Balance your hand and the instrumentationwith this finger.

PALM GRASP

When using the palm grasp, the index, middle,ring, and little finger hold the instrument so that it restsin the palm of your hand. Your thumb remains free tostabilize your hand in the patient's mouth, or it may be

Figure 3-18.—Modified pen grasp.

used to support an instrument when sharpening (fig.3-19). This grasp is rarely used in the mouth and onlywhen exceptional force is needed.

FINGER REST

Use a finger rest or fulcrum to maintain control ofthe instrument. It is a stabilizing point for your handwhile you are operating in the mouth. You should use afinger rest in the same arch and as close to the workingarea as possible. In the modified pen grasp, the third orring finger is always used as a finger rest. This fingercan rest on the teeth, the gingiva, another finger, or acombination of these. Do not use soft movable tissuefor a finger rest. When you are holding the instrumentin a pen grasp, use your third finger as the finger rest.When you are using the palm grasp, use your thumb for

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the finger rest. The same finger that is used as a fingerrest also acts as a fulcrum, the pivot point around whichthe necessary force to remove the calculus can beexerted. Figure 3-20 illustrates the correct fingerposition for a finger rest.

Figure 3-19.—Palm grasp.

Figure 3-20.—Finger rest.

ORAL PROPHYLAXIS PROCEDURES

As you perform the prophylaxis procedure,remember that you are treating a living, breathinghuman being. You must accomplish your task in amanner that does not irritate the patient. Your job isnot to chastise the patient for past dental neglect, but torehabilitate and educate the patient toward improvedoral health.

Before starting any scaling or prophylaxisprocedure, ensure that your patient takes out of themouth any removable partial or complete dentures thatare present. This lets you inspect all the oral tissuesand will avoid possible damage to the prosthetic teethduring the scaling or polishing procedures. Place theprosthetic appliance in a cup of water or in a moisttowel.

Be as gentle as possible during the scalingprocedure so that you do not injure the tooth or itssurrounding tissues. Frequently irrigate and suctionthe scaling site to prevent particles of calculus frombecoming implanted in the gingival tissues.

While scaling, you will occasionally need toremove calculus and debris from the working end ofyour instrument. You can do this in several ways. Youcan place a dappen dish containing hydrogen peroxideon the bracket table and simply dip the instrument tipinto the solution, or you can wipe the instrument on agauze sponge attached to the towel chain or held inyour non-scaling hand. Avoid wiping the instrumentdirectly on the patient's towel because blood and debrisfrom your hands or the instrument can stain thepatient's clothing.

A SYSTEMATIC APPROACH TOPERIODONTAL SCALING

You should approach each patient with a specificplan of treatment. This will vary with individualpatient needs. A routine oral prophylaxis for a patientwho practices adequate oral hygiene can usually becompleted in one appointment. Patients who haveneglected their oral health, such as those withperiodontitis and or have subgingival calculus, will beappointed with a dental hygienist or dentist.

Your examination and scaling procedure should bedone with a definite routine. By using a routine, youwill be able to treat as many teeth as possible from oneposition, and ensure you will not overlook any tooth ortooth surface. The recommended routine is as follows:

1. Mandibular anterior teeth

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2.

3.

4.

5.

6.

Right mandibular posterior teeth

Left mandibular posterior teeth

Maxillary anterior teeth

Right maxillary posterior teeth

Left maxillary posterior teeth

Starting with the mandibular anterior teeth,examine the facial and proximal surfaces. Then, scalethose surfaces. Next, examine and scale the lingualand proximal surfaces. After you have completed themandibular anterior teeth, follow the routine until theentire dentition (all teeth) has been examined andscaled.

CALCULUS REMOVAL

Dental Technicians are only allowed to removesupragingival calculus. Supragingival calculus isdefined as calculus above the gumline. Subgingivalcalculus removal and root planing are only to beperformed by a dentist or dental hygienist. Figure 3-21illustrates subgingival and supragingival calculus.

Sca l ing the t ee th r emoves ca lcu lus bymechanically fracturing the deposits off each tooth. Itis relatively simple to remove large deposits ofsupragingival calculus, but removing the smallerpieces that are left behind when the larger piecesfracture off takes practice to ensure the tooth surface iscalculus-free.

Supragingival calculus may be detected visually.It will appear as a white, chalky, or yellow deposit onthe tooth surface. Drying the tooth surface with airfrom the three-way syringe will make a deposit easierto see.

Figure 3-21.—Subgingival and supragingival calculus.

You can also detect supragingival calculus bypassing the point of an explorer over the teeth. Enamelwill feel hard and smooth as the explorer tip passesfreely over it. Calculus feels rough and will interferewith the free movement of the explorer tip. The easiestway to detect supragingival calculus is by using adisclosing agent. This will enable you to visuallyidentify stained areas of plaque and calculus.

SCALING INSTRUMENTS

Your choice of an instrument is determinedprimarily by the amount of calculus present. If thepatient has a large amount of supragingival calculus orheavy stain, you may want to start your scalingprocedure with the ultrasonic or sonic instrument.After you have removed the calculus or heavy stain,you then can use the various hand instruments toremove the remaining deposits. If the patient has a lightto moderate accumulation of supragingival calculus,you may choose to complete the entire procedure withhand instruments.

INSTRUMENTATION

After you have located the calculus deposits, youare ready to perform the instrumentation necessary toremove them. There are four basic scaling strokes:exploratory, vertical, horizontal, and oblique.

Exploratory Stroke

The exploratory stroke is used to determine thegeneral outline of the deposits. To perform theexploratory stroke, hold the scaler or curette lightly ina modified pen grasp. Holding the instrument lightlywill increase your sense of touch. Establish a fingerrest, then move the cutting edge of the blade across thetooth surface toward the gingiva. When you feel thecalculus, continue moving the blade until the cuttingedge reaches the border of the deposit. Do not insertthe blade below the gingiva. Position the cutting edgeof the instrument next to the border of the calculusdeposit (fig. 3-22). You are now ready to change to avertical, horizontal, or oblique scaling or workingstroke (fig. 3-23) depending on the location of thecalculus.

Vertical Stroke

The vertical stroke parallels the long axis of thetooth. Use this stroke to remove calculus from theproximal surfaces of the teeth. It is considered the

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Figure 3-22.—Exploratory stroke.

Figure 3-23.—Scaling strokes.

safest scaling stroke because the cutting edge of theinstrument does not come in contact with the epithelialattachment.

Horizontal Stroke

The horizontal stroke will parallel the gingivalmargin. Use this stroke cautiously to removesupragingival deposits from the facial and lingualsurfaces of the teeth.

Oblique Stroke

The oblique or slanted stroke is made at a 45° angleto the long axis of the tooth. Use this stroke to scale themajority of the tooth's surfaces. However, thedirection of the stroke that you select will depend onthe type of instrument, the area of the mouth, and thetooth surface involved.

Activating the Stroke

Before starting the working phase of the stroke,tighten your grip on the instrument. Use your hand,

wrist, and arm to activate the instrument (fig. 3-24).Avoid scaling with independent finger movements asthis technique is extremely fatiguing. Your workingstroke should be short, controlled, decisive, anddirected in a manner to protect the tissues from trauma.With a short stroke, you can maintain control of theinstrument and adapt the cutting edge to variations inthe tooth surface. Always keep as much of the workingblade (not just the point) on the tooth as possible. Theexact length of the stroke depends on the height of thedeposits. During the working stroke, you shouldslightly increase the pressure on the fulcrum to balancethe pressure of the instrument on the tooth.

Never remove calculus by shaving it in layers.Shaving often leaves a thin layer of calculus, which isdifficult to distinguish from the tooth surface. Thisthin layer can serve as a nucleus for new plaque andcalculus formation. After you have completed thescaling procedure, you are ready to polish the teeth.

POLISHING TEETH

The current treatment plan in the patient dentalrecord will indicate whether or not a tooth polishingshould be done. However, if the gingiva has beenirritated during scaling, you may have to schedule thePolishing Procedure for a later date. Have a dental

Figure 3-24.—Instrument activation.

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officer evaluate the tissue condition if any questionsexist.

Tooth polishing removes plaque or stainsremaining on the teeth after thorough scaling.Improper use of a prophy cup and abrasive paste canhave harmful effects on the teeth including: loss oftooth structure, removal of fluoride-rich surfaceenamel, thermal injury to the pulp, and trauma to softtissues.

Materials and Equipment

A typical tooth polishing setup (fig. 3-25) includesa mouth mirror, slow-speed handpiece with aprophylaxis angle attachment, rubber polishing cup,tapered bristle brush, dental floss, and prophylaxispaste.

Many different types of prophylaxis (sometimesabbreviated as "prophy") angle attachments areavailable. Disposable or single-use prophy angles arerecommended; however, sterilizable prophy angles areequally effective, can be more economical, and arewidely used in the Navy. There are latch and screw-type rubber polishing cups. Ensure that the prophyangle and the type of rubber cup you select arecompatible. Follow the manufacturer's instructionsfor use and maintenance of handpiece and prophyattachments.

The use of single-unit prophylaxis paste preventswaste and cross contamination. Commerciallyprepared pastes containing fluoride are commonlyused in the Navy and are available in popular flavors.Pastes are also available in fine, medium, coarse, andcoarse grits. Select the abrasiveness appropriate forremoval of the stains present. A fine paste will notefficiently remove heavy stain. A coarse paste will

Figure 3-25.—Tooth polishing setup.

needlessly remove enamel when treating fine stains. Atapered bristle brush may be used to polish the occlusalsurfaces of the teeth.

Precautions

You must be careful when you use the handpieceand prophylaxis attachment. Neither a polishing cupnor bristle brush should contact soft tissue. Suchcontact could injure the tissue. Only use the bristlebrush on occlusal surfaces of teeth, well away from thesoft tissue.

You must also be careful to avoid friction betweenthe cup or brush and the tooth. Friction causes heat,and heat can harm the tooth pulp and cause pain to thepatient. For this reason, always run the handpiece atthe slowest of the slow speeds. The speed of thehandpiece is controlled by a foot-operated rheostat.Use firm pressure when applying the rubber cup to thesurface that needs polishing. You will know that youhave applied sufficient pressure when you see the cup'sedge flare slightly. Don't bounce the cup on and off thetooth. Keep the cup in constant motion while incontact with the tooth. To avoid splattering paste,bring the cup almost in contact with the tooth beforethe cup starts turning. Follow all safety precautions.You should always wear protective gloves, glasses,and mask. Drape the patient to protect his or herclothing.

Polishing Routine

You should polish the patient's teeth according to adefinite sequence. A typical sequence would start withthe maxillary arch and polish the teeth as follows:

All facial surfaces—from the right quadrant tothe left quadrant.

All lingual surfaces—from the left quadrant tothe right quadrant.

All occlusal surfaces—from the right quadrantto the left quadrant.

As you polish, begin at the gingival margin of thetooth and work toward the occlusal or incisal edge,using vertical or oblique pulling strokes. Rinse theworking area with water from the three-way syringe asneeded and have the patient use the saliva ejector toremove the debris from the mouth.

You may not be able to reach all of theinterproximal areas with the polishing cup. To polishthese areas, place the polishing paste in the facial and

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lingual embrasures and carry it into the interproximalspace with dental floss or dental tape.

current treatment plan.

At the end of the polishing, carefully floss thepatient's teeth. This is an excellent opportunity to beginyour oral hygiene instruction. Have the patient watchyou with a hand-held mirror. When flossing iscomplete, rinse and remove any debris remaining inthe mouth. Once the teeth have been cleaned of plaqueand calculus, topical fluoride can be appliedprofessionally if the procedure is indicated in the

Fluoride Application

Topical fluoride can be administered by threedifferent methods. The first method involves theapplication of fluoride solution. This type of fluoridemust be painted on the teeth with a cotton tipapplicator. The second method of fluoride applicationis the use of a concentrated fluoride rinse. The thirdmethod is the tray technique, which is used to applyfluoride gels. Gel application is generally regarded asthe most effective means of topical fluoride treatment.We will focus our attention on fluoride gel application.

A variety of trays are available for fluoride gelapplication. The use of disposable trays reduces thechance of cross contamination and eliminates the needto clean and sterilize reusable ones. Trays come inseveral arch sizes to ensure optimal fit for each patient.The tray should provide complete coverage of allerupted teeth without going beyond the most distaltooth surface in the arch. Custom-fitted trays can bemade that require less gel and promote contact of thegel with the teeth. The extra time and expense ofcustom fluoride tray fabrication will limit the use tospecific patients who require daily application offluoride gel.

Reexamine the mouth to estimate the size of thedental arches and identify any features such asmalposed teeth or bony tori that will influence trayselection. Select a maxillary tray and try it into thepatient's mouth. Make sure all teeth will be contactedby the gel. Remove it and do the same for themandibular arch. Refer to the manufacturer'sinstructions for the amount of gel required for eachtray. A narrow strip of material along the bottom of thetray is normally adequate. This technique willminimize the amount of gel required and will reducethe chance that excess gel will be swallowed by thepatient. The patient's teeth must be dried and kept asdry as possible until trays are inserted. Dry each arch

separately before placing the tray into the patient'smouth.

First place the mandibular tray. Retract a cornerof the mouth with your finger. Insert one end of thetray in the mouth at an angle and then rotate the otherend of the tray into the mouth. Insert the saliva ejectorbefore placing the maxillary tray. Place the maxillarytray in a similar fashion and ask your patient to closehis or her teeth together gently. Refer to themanufacturer's instructions for the amount of time thegel remains in the mouth. Generally, application is nolonger than 4 minutes. After the trays have beenremoved, allow your patient to expectorate (spit) anyremaining fluoride from the mouth. Instruct thepatient not to rinse, drink, eat, or smoke for at least 30minutes.

ORAL HYGIENE INSTRUCTIONS

A vital part of any preventive dentistry program isthe education and motivation of patients in proper oralhygiene. During the appointment you must take thetime to explain the harmful effects of bacterial plaqueand demonstrate proper tooth brushing and flossingtechniques. It is recommended that you review DentalTechnician, Volume 1, chapter 5, "Oral Pathology,"and chapter 8, "Nutrition and Diet," as this informationalso plays an important role in oral hygiene.

INSTRUCTION ATMOSPHERE

The atmosphere you create for your oral hygieneinstruction will influence your ability to communicatewith the patient. Position yourself in front of thepatient so that you can look directly into the eyes andobserve the patient's responses to your instructions.You may want to repeat or clarify points that thepatient's response suggests he or she does notunderstand or if the patient questions what you havesaid. In most cases, sitting on the dental stool andfacing the patient from the front is a good instructionalposition. This position allows you to view the patient'sfacial expression. Being at the same eye level as thepatient also helps you establish rapport, since you arenot talking "down" to them.

Talk direct ly to your pat ient and smileoccasionally. If you stare at the wall or some otherinanimate object during your presentation, the patientwill get the impression that you are not sincere orinterested. Use simple words, and explain anyscientific or technical terms with which the patientmay not be familiar. Your patient may not know that

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"gingiva" is the technical term for "gums," and theymight think "calculus" is a form of mathematics. Usesimple layman terms.

patient for past neglect, but to educate and encourageimprovement in oral hygiene.

The use of visual aids, such as charts and patientliterature, can help illustrate the progression of dentaldisease or effective hygiene techniques and reinforceyour discussion with the patient. The use of adisclosing agent can increase the impact of yourinstruction on the patient. By using this agent beforethe appointment, you can actually show the patient theareas that he or she missed during the cleansingtechnique. Remember your job is not to chastise the

HOME CARE

Home care is NOT limited to the home. Let yourpatients know that they can keep extra toothbrushesand dental floss at work. The difference between oralhygiene and dental disease is not toothbrushing, butmouth cleansing. Everybody brushes their teeth, butthe goal is to thoroughly clean the mouth.

One of the major causes of tooth decay andperiodontal disease is bacterial plaque. Bacterialplaque is an almost invisible film of water, containingcells and millions of living bacteria. To prevent dentaldiseases, you must effectively remove this destructivefilm at least once during a 24-hour period. By keepingyour teeth and gums clean, you will have better health,retain your natural appearance, enjoy chewing andtalking, and prevent bad breath.

EFFECTIVE TOOTHBRUSHING

The toothbrush can remove the bacterial film fromthe facial, lingual, and occlusal surfaces of the teeth.Brush gently but with enough pressure to feel thebristles on the gum. Do not use so much pressure thatyou feel discomfort. The method we will describehere, the "Modified Bass" technique, is effective andrelatively easy for most patients to perform.Sometimes other methods are recommended in specialsituations, such as malocclusion.

Toothpaste foams and prevents you from seeing ifyou are placing the brush properly. While a person islearning to brush properly, it is best to omit toothpasteor use it in a second brushing.

Your toothbrush should have soft, multituftednylon bristles. It should have a rigid plastic handle anda small and flat head.

For all facial surfaces and the posterior lingualsurfaces, point the bristles at the teeth at a 45° angle.Lay the bristles in the sulcus area and use a gentlevibrating motion (fig. 3-26).

For the lingual surfaces of the anterior teeth,place the brush as shown in figure 3-27 and use smallcircular scrubbing strokes.

When brushing the occlusal surfaces, place thebristles flat on the surface and use the same scrubbingstrokes as for the other surfaces (fig. 3-28). Move thebristles around the mouth in a regular pattern so as not toskip any areas.

ELECTRIC TOOTHBRUSHES

Many electric toothbrushes are accepted by theAmerican Dental Association (ADA) and have earnedits seal of approval. Always follow the manufacturer'sinstructions on the use and maintenance of theseproducts.

Figure 3-26.—Brushing the sulcus area.

Figure 3-27.—Brushing the lingual surfaces of anterior teeth.

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Figure 3-28.—Brushing the occlusal surfaces.

USE OF DENTAL FLOSS

For most people, dental decay and periodontaldisease most often occur between or on the proximalsurfaces of teeth. The toothbrush cannot clean theseareas effectively or clean behind the last tooth in eacharch. Dental floss is best for cleaning these areas. Bothwaxed and unwaxed floss clean equally effectively.However, a patient with very tight interproximalcontact areas may find waxed floss is easier to use.Patients who have suffered a loss of interproximaltissues may use dental tape.

When patients are first learning to floss, they mayfind it difficult to accomplish. You should assure themthat with practice, flossing will become easier. Inaddition, some patients may feel discomfort and havebleeding around the gingiva the first few times theyfloss. Assure them that the discomfort and bleedingwill go away in a day or two. To ease the discomfort,you may recommend that such patients should use awarm salt water rinse after flossing.

To properly floss, cut off a piece of floss about 18inches long and lightly wrap the ends of the flossaround your middle finger, as shown in figure 3-29.The fingers controlling the floss should not be morethan one-half inch apart. Do not force the flossbetween the teeth. Insert it gently by sawing it backand forth at the point where the teeth touch each other.Let it slide gently into place. With both fingers, movethe floss up and down on the side of one tooth, and thenrepeat on the side of the other tooth until the surfaces

Figure 3-29.—Floss wrapped around middle fingers.

are "squeaky" clean. Use your fingers to curve or bendthe floss around the tooth. Go carefully under the gumline with the floss since this is a sulcus where plaquecollects. Slide the floss down until you feel resistance,but do not go far enough into the gum to causediscomfort, soreness, or cut the gum tissue that willcause bleeding. When the floss becomes frayed orsoiled, a turn from one middle finger to the other bringsup a fresh section.

To clean between the upper left back teeth, passthe floss over your thumb and forefinger of your righthand (fig. 3-30). To see the proper position of the hands,look at figure 3-31. The thumb is placed on the outsideof the teeth and helps hold the cheek back.

To clean between the upper right teeth, pass thefloss over your right thumb and forefinger on your lefthand. Now the right thumb is outside the teeth and theleft forefinger is on the inside.

Figure 3-30.—Floss position for the maxillary posterior teeth.

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Figure 3-31.—Hand position for flossing maxillary posterior

teeth.

To clean between all lower teeth, hold the flosswith the forefingers of both hands (fig. 3-32). You caninsert the floss gently between all lower teeth with thefloss over your forefingers in this position. Figure 3-33illustrates the correct method for flossing between thelower back teeth, using the two forefingers to guide thefloss.

EVALUATION

Are your patient's teeth clean? When flossing hasbeen completed, rinse vigorously with water to removefood particles and plaque. Also advise the patient torinse with water after eating if unable to floss or brush.Neither rinsing alone nor water-spraying devicesremove the bacterial plaque because of the glue-like

Figure 3-32.—Floss position for the mandibular teeth.

Figure 3-33.—Hand position for flossing mandibular posteriorteeth.

material in the plaque. To ensure all areas of the teethare clean, a disclosing agent can be used to determine ifany surfaces on the teeth were missed during flossing.

SENSITIVITY

After treatment of the teeth or gums, the exposedroot surfaces may be sensitive to cold and heat. Thiscondition is usually temporary if the teeth are keptclean. If the teeth are not kept clean, the sensitivitymay remain and become more severe. For the fewpatients who have severe sensitivity, the use ofspecially medicated toothpastes and mouthwashesmay be recommended.

DENTIFRICE

Although dentifrices (toothpaste) are notnecessary for effective cleaning of the teeth, they maybe refreshing for the patient and have a psychologicalbenefit. Instruct your patients that if they wish to use adentifrice, they should select a fluoridated toothpastedisplaying the ADA seal of approval.

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MAINTENANCE OF PROSTHETICAPPLIANCES

If your patient has a prosthetic appliance, tell himor her to take the removable appliance out of the mouthafter meals and thoroughly brush it. Patients shoulduse a good prosthetic appliance brush and theirpreferred dentifrice or soap and water. Have the patientfollow the dentist's instructions regarding how long toleave the appliance out of the mouth while sleeping togive the tissues proper rest and how to take care of theappliance when it is not worn.

Plaque accumulates on the surfaces of abutmentsand beneath the pontics of fixed partial dentures(bridges). Floss threaders are thin plastic devices thathelp the patient direct the floss into these areas. Fixedpartial dentures should also be cleaned at least oncedaily.

ORAL HYGIENE AIDS

Toothpicks, interdental proximal brushes, oralirrigators, and mouthwashes are aids to oral hygiene.They may be used in addition to, but not in place of,tooth brushing and flossing. These products will berecommended by a dentist or dental hygienist andshould bear the ADA seal of approval.

APPLICATION OF PIT AND FISSURESEALANTS

A pit and fissure sealant is a plastic resin-likematerial that is applied to the tooth surface andhardened. The plastic resin bonds into the depressionsand grooves (pits and fissures) of the chewing surfacesof back teeth. Sealants are highly effective inpreventing pit and fissure caries in premolars andmolars. The sealant acts as a barrier protecting enamelfrom plaque and acids. Figure 3-34 illustrates a beforeand after drawing of a sealant on a tooth. Acid-etchresin sealants are classified into three types, based onthe method by which they are cured (hardened):

Ultraviolet light-cured

Chemically or self-cured

Visible light-cured

As a basic dental assistant, you may receivetraining in expanded functions to place pit and fissuresealants as described in BUMEDINST 6600.13.Check with your command on cert if icat ionrequirements. Pit and fissure sealants may only beplaced by certified personnel. Only a dental officer can

Figure 3-34.—Before and after applying a sealant on a tooth.

authorize and recommend what teeth require sealants.This will be noted on the patient's treatment plan.

The following clinical guidelines should befollowed for successful sealant application:

Ensure the patient's treatment plan indicateswhat teeth require sealants.

Ensure the proper eye and clothing protection arein place for you and the patient.

The teeth must be isolated to prevent salivacontamination of the surfaces to be sealed. Theisolation must provide adequate access to observe thefield and to reach the tooth surfaces with the appropriateinstruments. A rubber dam is the preferred method ofisolation, but if a rubber dam cannot be used, cotton rollisolation can be effective.

The tooth surfaces should be cleaned with aprophylaxis brush or rubber cup and a cleansing agentcontaining no oil or other substance that cannot becompletely and quickly washed away using an air/watersyringe with high-speed evacuation.

When the teeth are effectively isolated fromsaliva contamination, the tooth surfaces are dried andthen etched by an application of a 30 to 50 percentphosphoric acid solution for 15 to 20 seconds. Etchingshould cover all the areas to be sealed.

The acid should be washed away with water.The surfaces are then carefully re-dried and inspected toensure that the area intended for sealant has a "frosted"appearance. The absolute avoidance of contaminationwith saliva or air-line moisture or oil is critical from thetime of acid removal and drying, until the sealant is

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cured. If contamination is suspected, re-etching of thesurface for 20 seconds is indicated.

The sealant should be applied according to themanufacturer's instructions. Care should be taken toavoid entrapment of air bubbles, to extend the sealantinto all the grooves and pits, and to avoid extension ofthe sealant onto unetched smooth surfaces or softtissues. The sealant must remain uncontaminated andundisturbed until it is cured to hardness.

The sealant should be examined by yourself first,and then check ed by a dentist to ensure that

underextension, overextension, undercuring, voids, andhigh spots have not occurred. A reasonable attemptshould be made to remove the sealant to determine ifadequate bond strength has been established.

Fluoride should not be applied to the enamelsurface immediately before a sealant procedure isinitiated. Fluoride may be applied immediately aftersealant application.

The most common reason for sealant failure iscontamination of the etched surface with saliva or air-line moisture (from the air syringe) or oil.

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CHAPTER 4

OPERATIVE DENTISTRY

INTRODUCTION

Operative dentistry is the area of dental practiceconcerned with the prevention and treatment of defectsin tooth enamel and dentin. Since many patients needtreatment that is provided in operative dentistry, this iswhere most of the dental assistants are assigned.Operative dentistry includes the treatment andrestoration of carious teeth with metallic andnonmetallic dental materials. These materials areusually amalgam, composite resins, and glass ionomerrestorations.

PURPOSE

Operative dentistry provides treatment to restore apatient’s dental condition to a healthy, functional, andesthetically (pleasing to the eye) acceptable level.Operative dentistry primarily is responsible for therestoration of decayed or fractured teeth. This chapterprovides information and procedures that you may berequired to perform in operative dentistry.

AREAS OF OPERATIVE DENTISTRY

You must be aware that each operative proceduremay not be performed in the same manner. Basicprocedures are usually performed during eachoperative appointment. Some of these procedures arealso used in other dental specialties. The areasdiscussed in this chanter are as follows:

Identification of operative instruments

Miscellaneous instruments, materials, andequipment

Four-handed dentistry

Basic dental procedures

Operative procedures

Supply procedures

IDENTIFICATION OF OPERATIVE

INSTRUMENTS

Because of the many hard to reach areas in thehuman mouth and various functions required,

operative instruments come in a wide variety of sizesand shapes. To be an effective dental assistant, youmust be able to understand why, where, and when thedentist will use them. We will discuss hand cuttinginstruments, amalgam instruments that consist ofcondensers, carvers and burnishers, and composite(resin) instruments.

HAND CUTTING INSTRUMENTS

Many dental procedures require the use of handinstruments with sharp cutting edges. This cuttinginstrument group used in operative dentistry includesexcavators, chisels, hatchets, hoes, and gingivalmargin trimmers. They are used in the cavitypreparation of both amalgam and composite (resin)restorations.

Spoon Excavators

The spoon excavator is a double-ended instrumentwith a spoon, claw, or disk-shaped blade. Spoonexcavators are used primarily to remove debris fromtooth cavities. Their tips and sides are designed forcutting action. The most common sizes are the smalland the large (fig. 4-1) spoon extractors.

Chisels

Dental chisels are commonly referred to asminiature chisels. Chisels are used to cleave (split)tooth enamel, to smooth cavity walls, and to sharpencavity preparations. The two most common types usedin operative dentistry are the Wedelstaedt and bianglechisels (fig. 4-2). The Wedelstaedts have slightlycurved shanks and are used primarily on anterior teeth.The biangle chisels have two distinct angles—one atthe shank, and one at the working end. This designallows access to tooth structures that would not bepossible with straight chisels.

Hatchets

A dental hatchet (fig. 4-3) resembles a camper'shatchet, except much smaller. Like dental chisels,some have single cutting ends, and others have cuttingedges on both ends of the handle. Hatchet blades are set

4-1

Figure 4-1.—Small and large spoon excavators.

Figure 4-2.—Wedelstaedt and biangle chisels.

Figure 4-3.—Hatchet.

at a 45- to 90-degree angle from the shank. Theseinstruments have different lengths and widths ofblades. Hatchets are used on the wall of the cavitypreparation to cleave enamel and cut dentin so therewill be a sharp cavity outline.

Hoes

Dental hoes (fig. 4-4) look like a miniature gardenhoe. They are used with a pulling motion to smooth andshape the floor and sides of cavity preparations. Hoeblades are set at a 45- to 90-degree angle from theirhandle.

Gingival Margin Trimmers (GMTs)

The gingival margin trimmers (GMTs) (fig. 4-5)are modified hatchets that have working ends withopposite curvatures and bevels. As the name implies,GMTs are used to trim, smooth, and shape the gingivalfloor of a cavity preparation. GMTs are available indouble-ended styles and are used in pairs, such as the#26 and #27. This is because the working ends of theeven-numbered instruments are designed for use onthe distal surfaces, and the odd numbered are used onthe mesial surfaces.

AMALGAM RESTORATIONINSTRUMENTS

The instruments discussed in this section are usedwhen the dentist elects to use an amalgam or atemporary dental material to restore a tooth.

4-2

Figure 4-4.—Hoe.

Figure 4-5.—Gingival margin trimmers (GMTs).

Condensing Instruments

To deliver the amalgam to the cavity preparationand properly condense (pack) it, the dentist will use avariety of instruments. Amalgam carriers andcondensers are used for this purpose.

completed, eject any remaining a: nalgam alloy fromthe carrier into the amalgam well The carrier is nolonger serviceable when the amalgam is allowed toharden in the carrier.

CONDENSERS. —Amalgam condensers, oftencalled pluggers, are instruments used to condense or

AMALGAM CARRIERS.—Amalgam carriers(fig. 4-6) transport the freshly prepared amalgamrestorative material to the cavity preparation. Thesecarriers have hollow working ends, called barrels, intowhich the amalgam is packed for transportation. Bothsingle and double-ended carriers are available with avariety of barrel sizes including: mini, large, andjumbo. When the lever (located on the top of thecarrier) is depressed, the amalgam is ejected into thecavity preparation. Normally, two carriers are usedduring the amalgam placement procedure. This savestime for the dentist who is ejecting or condensing acarrier load while you are refilling the carriers. Apoorly packed carrier of amalgam handed to the dentistmay fall out before it is ejected into the cavitypreparation. It is your responsibility to ensure that allcarriers are properly packed before the transfer to thedentist. After amalgam material placement is

pack the amalgam filling materials into the cavitypreparation. The hammer-like working end is largeenough to compress the soft amalgam without sinkinginto it. Condensers come in single- and double-endeddesigns. They have various shaped and sized workingends, which may be smooth or serrated as shown infigure 4-7.

Carvers

After the amalgam is condensed, it must then becarved to approximately the same original toothstructure. Carvers have sharp cutting edges that areused to shape, form, or cut tooth anatomy into amalgamrestorations. Figure 4-8 illustrates these instruments thatcome in assorted shapes and sizes in double-endeddesigns. Many carvers were designed for carvingspecific tooth surfaces. The Interproximal and #1/2Hollenback were designed for carving proximal (inbetween) tooth surfaces; whereas, the discoid-cleoid #89/92 and Tanner #5 are used on occlusal surfaces.Carvers shaped similar to Vignon or Frahm #2/3 (also

4-3

Figure 4-6.—Amalgam carriers.

Figure 4-7.—Amalgam condensers.

called acorn carvers) are used to quickly carve thebasic anatomy on occlusal surfaces. As withcondensers, dentists also have favorite carvers thatthey use routinely. You must know the dentist'spreference so that you can have the desired instrumentready when it is needed.

Burnishers

When the carving is complete, the dentist may use

burnishers to smooth and polish the restoration, and to

remove scratches left on the amalgam surface by a

carving instrument. Burnishers have smooth rounded

4-4

Figure 4-8.—Carvers.

working ends and come in single- and double-endedtypes. Some of the more commonly used burnishersare shown in figure 4-9.

COMPOSITE RESIN INSTRUMENTS

A variety of double-ended instruments make upthis instrument group. They are used to transport andplace dental cements, resins, temporaries, andinsulating and pulp-capping materials. The workingends on composite resin instruments range fromvarying small cylinders to assorted angled, paddle-likeshapes. Figure 4-10 illustrates the Woodson #3, #W3,and #11 (also know as Stellite), which are some of thecommonly used instruments in this category.

Other types of composite resin instruments aremade of plastic. Plastic instruments can be heatsterilized and used on composites and cements. Theyeither come included in the kit of resin material fromthe manufacturer or, in some cases, can be ordered as aset as shown in figure 4-11. Some advantages to usingplastic instruments are that they won't discolor orcontaminate the composite restoration, and compositeresin material will not cling to the instrument. Figure 4-9.—Burnishers.

4-5

Figure 4-10.—Composite and cement instruments.

Figure 4-11.—Plastic composite instrument set.

Another instrument frequently used with etchingand bonding procedures associated with compositeresins is a disposable brush with a reusable handle. Anexample is shown in figure 4-12. Single-use disposalbrushes are being used more frequently, aiding in goodinfection control practices.

CEMENT AND INSULATING BASEINSTRUMENTS

The instruments in this group are used for mixingand handling restorative resin, and various temporaryrestorative, insulating, and pulp-capping materials.

Spatulas

Three different spatulas are available for mixingrestorative materials, as shown in figure 4-13. Some ofthese spatulas can cause discoloration in the materialbeing mixed. The selection of a mixing spatula is notcritical except when preparing a permanent anteriorcomposite restoration. Some composite restorationmaterial discolors easily, so use the spatulas providedby the manufacturer when working with it. The single-ended #322 and #324 are suitable for mixing othermaterials other than composites. A smaller version forthe #324 is the #313 spatula. The #313 is used formixing small quantities of cement.

Insulating Base Instruments

Insulating base instruments have a small metal ballat the working end and are often referred to as calciumhydroxide instruments. They are used to mix, carry,and place insulating bases, and are available as a

Figure 4-12.—Disposable brush and handle. Figure 4-13.—Spatulas.

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single-ended instrument or as a double-endedinstrument, shown in figure 4-14.

MISCELLANEOUS INSTRUMENTS,MATERIALS, AND EQUIPMENT

A number of miscellaneous instruments,materials, and equipment are used in operativedentistry. Instruments such as dental mirrors,explorers, and cotton forceps are called a basic dentalset (BDS) and are usually used in all dental specialties.

ASPIRATING SYRINGE

This syringe is used in dentistry to inject a localanesthetic. The aspirating syringe differs from mostsyringes in that it is designed to inject anesthetic from acarpule (fig. 4-15). The parts of an aspirating syringeconsist of a threaded tip where the needle attaches, abarrel where the carpule is placed, a piston rod(plunger) with a harpoon attached that embeds itselfinto the rubber stopper of the carpule, a finger grip, anda thumb ring (fig 4-16). The harpoon allows the dentistto aspirate (draw back) the injection site to see if theneedle tip is located in a blood vessel before injectingthe anesthetic solution. Once the harpoon is engagedinto the rubber stopper of the anesthetic carpule, thedentist can apply inward or outward pressure on the

Figure 4-14.—Double-ended calcium hydroxide instrument.

Figure 4-15.—Anesthetic carpule.

stopper by exerting pressure on the thumb ring. Pullingthe thumb ring outward also pulls the plunger outwardproducing an aspirating effect; whereas, pushinginward forces the anesthetic solution through theneedle.

ASPIRATING SYRINGE NEEDLE

The aspirating syringe needles used in dentaltreatm ent arrive sterile and are disposable. They aredesigned for a single use, and are available in differentgauges and lengths (fig. 4-17). The gauge of a needlerefers to the diameter of the hollow shaft of the needle.The larger the gauge, the smaller in diameter theneedle. The lengths of the needles vary, and areclassified as long (L) or short (S).

Each needle has either a plastic or metal hubdesigned to screw onto the threaded end of the syringe(fig. 4-18). This hub is positioned to permit the needleto extend inward to penetrate the rubber seal portion ofa loaded anesthetic carpule.

The plastic caps covering the sterile needle areeasily removed from both ends. When placing theneedle onto the syringe, remove only the cap thatcovers the syringe end on the needle. This maintainsthe sterility of the needle portion used to inject thepatient.

Normally, you prepare the anesthetic syringe witha short needle (13/16 inch in length) for maxillaryinjections, and a long needle (17/8 inches in length) formandibular injections. The tip of the needle has abeveled angle, which is turned toward the alveolus toaccurately deposit the solution.

RUBBER DAM INSTRUMENTS

Rubber dam instruments include the rubber dampunch, clamps, clamp forceps, and frame. Theseinstruments prepare and maintain the position of thinsheets of latex rubber (rubber dam material). Therubber dam itself is used to isolate a designated tooth orteeth in the mouth before certain operative, endodonticand preventive dentistry procedures are performed.The rubber dam provides a clean, dry field of operationand improves the dentist’s view of the operating site. Italso keeps fluids, tissues, and the tongue away from theoperating site and prevents the patient fromaccidentally swallowing or aspirating debris.

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Figure 4-16.—Parts of an aspirating syringe.

Figure 4-17.—Different gauges and lengths of aspiratingsyringe needles.

Rubber Dam Punch

The rubber dam punch is used to make necessaryspaced holes in the rubber dam material. The workingend is designed with a plunger on one side and a wheelon the other side (fig. 4-19). This wheel has differentsized holes on the flat surface facing the plunger.These features let the operator select and adjust the

Figure 4-18.—Parts of the aspirating syringe needle.

wheel to punch the desired diameter hole in the rubberdam.

Figure 4-19 also illustrates the recommendedholes on the wheel to use. The largest hole is used onthe tooth that your clamp will go on. The last fiveremaining holes correspond to the teeth that areincluded in the isolation.

Rubber Dam Clamps

After the required number of holes are punched inthe rubber dam, it is stretched to fit over each designedtooth. To maintain a snug fit around the neck of the

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Figure 4-19.—Two styles of rubber dam punches.

tooth, a rubber dam clamp is used. These clamps aremade of spring steel in various sizes (fig. 4-20) to fitthe general contours of the different teeth. You willneed to know some of the commonly used clamps andtheir area of use, which are shown in table 4-1.

Clamps commonly used in pediatric dentistryinclude the #2, #4, #8A, and #14A. Clamps with "W"prefixes, such as the #W8A or W3, indicate that theclamps are without wings on the outer portionsopposite the holes.

Table 4-1.—Commonly Used Rubber Dam Clamps and

Their Area of Use

Clamp # Area of use in the mouth

0 Primary teeth

2 Small bicuspids

W3 Bicuspids and small molars

7 Mandibular molars

W8A Partially erupted molars

9

2 1 2

Anterior teeth

Anterior teeth

Figure 4-20.—Rubber dam clamps.

The space between the gripping edges of the clampis narrower than the diameter of the correspondingtooth. Thus, to place the clamp around the tooth, it isnecessary to spread the gripping edges wider than thetooth's diameter. To spread the gripping edges, rubberdam clamp forceps are used.

Rubber Dam Forceps

The rubber dam clamp forceps (fig. 4-21) aredesigned to spread the two working ends of the forcepsapart when the handles are squeezed together. The

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Figure 4-22.—Adult rubber dam frame.

Figure 4-21.—Rubber dam clamp forceps.

working ends have small projections that fit into twocorresponding holes on the rubber dam clamps. Thearea between the working end and the handle has asliding lock device. This sliding lock device locks thehandles in positions while the provider moves therubber dam clamp around the tooth.

Rubber Dam Frame

To place and clamp a rubber dam around the toothis not enough. The dentist still needs something to holdthe loose outer edges of the rubber dam sheet so that thearea is visible, and provides access to the tooth beingtreated. The need is met with an instrument called therubber dam frame. Most of the rubber dam frames usedtoday are U-shaped. One of the most popular is theYoung frame, which is available in adult (fig. 4-22)and pediatric sizes. When the edges of the rubber damare connected to the small, sharp projections on thisU-frame, there is adequate access to, and visibility ofthe area of treatment.

RUBBER DAM APPLICATION

The use of the rubber dam is an important part ofquality dental treatment and infection control. To savevaluable chairside time, place the rubber damfollowing the administration of local anesthetic (asdirected by the dentist). To place the rubber dam, you

will need the rubber dam material, frame, punch,clamps, and clamp forceps.

Preparation

The first step in applying the rubber dam is tocheck the contact areas of the teeth to be isolated. Use apiece of dental floss to do this. The next step is todetermine which tooth the rubber dam clamp will beplaced upon. Once this is determined, select a rubberdam clamp for a trial placement.

CAUTION

To prevent the patient from aspirating orswallowing the rubber dam clamp, always tiedental floss (ligature) on the bow of the clampbefore placing it in the patient’s mouth.

A simple and secure method is put both ends of apiece of floss together and place them on a flat surface.This forms a looped end where the floss is folded inhalf. Place the clamp over the floss with the bow of theclamp facing up. Now, place the two loose endsthrough the looped end and carefully pull the looseends through the loop until the floss is secured tightlyover the bow of the clamp (fig. 4-23). You should now

Figure 4-23.—Ligature on rubber dam clamp.

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have a securely placed ligature on the clamp. You arenow ready to place the clamp on the rubber damforceps.

Hold the clamp with the bow facing upward andaway from the forceps. Place the small projections onthe working ends of the rubber dam forceps into thecorresponding holes on the rubber dam clamp.Squeeze the handles of the forceps together to alignprojections with the corresponding holes on the clamp.Once the clamp is placed on the forceps, tilt the forcepsupright and slide the locking device on the forcepsdownward to lock the handles in position. Locking theforceps handles is necessary to continue the tensionrequired to keep the clamp attached to the forceps.Now the clamp is ready for trial placement.

Pass the rubber dam forceps, with the working endcovered, with the palm of your hand and the clamppointed toward the placement position of the tooth. Besure to hold on to the ligature while the clamp ischecked for proper fitting. Normally, the clamp shouldfit near or slightly below the cementoenamel junction.To stabilize the clamp, all the tips of the clamp must bein contact with the tooth to establish a facial lingualbalance. Exercise care to ensure that the clamp tips donot impinge on the gingival tissues. If it does, it willcause the patient to experience pain. If the clamp is notplaced properly, it may spring off the tooth and causeinjury. Caution is advised to stabilize the clamp firmlyon the tooth before the clamp forceps are loosened.Once the trial placement is complete, remove theforceps and attach the clamp until final placement.

To prepare the rubber dam material, you need therubber dam punch to make the appropriate number ofholes of varying sizes. The punch has an adjustablewheel with holes of varying sizes. By adjusting thewheel, holes of different sizes are produced in thematerial when the cutting tip strikes the hole in thewheel. The holes in the rubber dam material must bepunched firmly and cleanly. A ragged hole or tag willtear easily as the dam is placed over the crowns of theteeth. A ‘ragged hole also may cause leakage ofmoisture around the tooth.

Ideally, the rubber dam material is marked (fig.4-24) with predetermined markings of an average archusing a rubber dam stamp and ink pad. This makespunching the rubber dam material easier because youhave a pattern to follow with the normal shape of thearch and spacing alignment of the teeth. Beforepunching the material, always check the oral cavity forany missing, misaligned, or extra teeth. You will needto make adjustments from the standard pattern for

these items. Punch the hole for the tooth to be treatedfirst. Then, determine what additional holes must bepunched. Normally, you will punch holes for the twoanterior and at least one tooth posterior to the toothbeing treated. An exception to this is root canaltherapy when only the involved tooth is exposed. Afterthe holes are punched, apply a slight amount of watersoluble (brushless shaving cream) lubricant to the backof the material over the crowns and contact areas of theexposed teeth. Now the rubber dam is ready forplacement into the oral cavity.

Placement

The rubber dam material and clamp can be placedusing several methods. The first method usuallyrequires assistance. Place the rubber dam frame on theoutside of the dam with the bow of the frame facingout. Stretch the dam material from side to side tosecure the corners of the dam on the four projections atthe corner of the frame. The rubber dam materialshould appear baggy on the frame rather than tight toallow easier placement in the oral cavity. Pass therubber dam and attached frame to the dentist forplacement in the oral cavity. As the dentist stretchesthe rubber dam material over each tooth to be isolated,the assistant uses floss to slip the septum (rubber dammaterial between the holes) between the teeth withouttearing the material. Always place the floss on thetooth, never directly on the rubber dam itself.Placement of the floss upon the tooth assists inbringing a single thickness of the dam through the

Figure 4-24.—Marked rubber dam material.

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proximal contact when the floss is carried through.Floss placed on the rubber dam itself tears the dam andrequires the passing of two thicknesses of the damthrough the contact. Once the floss passes the contactof the teeth, release the lingual end of the floss. Loopthis end toward the opposite end and floss through thecontact again. Now, gently remove the floss by pullingit from the side horizontally, rather than attempting topull the floss back up through the contact vertically.Continue using the floss to invert the inter-proximalseptum, mesially and distally as well. Inversion of therubber dam turns the edges of the dam inward or under,around the isolated teeth, to provide a seal. After this iscompleted, pass the rubber dam clamp forceps andattached clamp to the dentist for final placement on thetooth. Adjustment of the rubber dam material on theframe can be made at this time to ensure a smooth andstable fit. Wrap the ligature attached to the clamparound a projection on the side of the frame. Thisprevents the clamp from becoming a dangerousprojectile if it should spring off the tooth. Pass a dullinstrument, such as a stellite instrument, to theprovider for inversion of the rubber dam on the facialand lingual areas of the exposed teeth. Dry the exposedteeth with air from the three-way syringe as needed toassist in the inversion.

The second method places the rubber dam clampon the tooth first. Then slip the rubber dam materialover the clamp. Next, in either order, attach the frameand expose the remaining teeth through the holes.Secure the clamp ligature to the frame. Then invert themesial and distal septum with floss, and the facial andlingual areas with a dull instrument accompanied withair from the three-way syringe.

In the third method, the clamp is held in the rubberdam forceps and the rubber dam placed over the bow ofthe clamp. Holding the edges of the rubber dam withyour fingers, use the forceps to carry the dam andclamp into the patient’s mouth. Place the clamp on thetooth and remove the forceps. Continue the placementas in the second method. The last two methods ofrubber dam placement are valuable when a rubber dammust be placed by one individual rather than two.After the restoration is placed, remove the rubber dam.

Removal

Before the rubber dam is removed, use the watersyringe and high-volume evacuator (HVE) to flush outall debris that collected during the procedure. Ratherthan pulling the septa through the contact of a newlyplaced restoration, the septa is cut. Stretch the rubber

dam material outward in the facial area of the isolatedteeth. This pulls the septa facially to provide access forcutting. Use a pair of small blunt-nose scissors to cuteach septum of the rubber dam from the facial aspect(fig. 4-25). When all the septa are cut, gently pull thedam lingually to free the rubber dam completely fromthe interproximal spaces. Use the clamp forceps toremove the clamp. Simultaneously, remove the clampligature from the frame. Set the clamp forceps andclamp aside. Now, remove the dam with the frameattached. Wipe the patient's mouth, lips, and chin witha tissue or gauze. Carefully inspect the dam on a flatsurface for missing pieces. If a fragment of the rubberdam is missing, check the corresponding interproximalarea of the oral cavity with a mirror and explorer.Pieces of the rubber dam left under the free gingivacause severe gingival irritation. Use dental floss toremove any material stuck between the teeth. Rinsethe patient’s mouth with the water syringe and HVE toremove all debris from the oral cavity.

MATRIX RETAINERS

Matrix retainers are used to hold the matrices(metal bands or strips) firmly in place around a tooth.Matrix retainers and metal bands are used incombination for a temporary mold while the fillingmaterial is being packed into place. The Tofflemireretainer (or matrix retainer) is available in threedifferent designs: the universal straight, contra-angle,and contra-angle junior (pedodontic) shown in figure4-26. These retainers are practically maintenance free.They can be heat sterilized along with other dentalinstruments. Your part in maintaining matrix retainersis to check them periodically and replace those withbadly worn screw threads. You are also expected toattach the correct matrix band to the appropriateretainer in anticipation of the dentist’s needs.

Figure 4-25.—Cutting rubber dam septum.

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Figure 4-26.—Matrix retainers.

Figure 4-27.—Amalgam matrix bands. A: Precontoured.

B: Junior (Pedodontic #15 with aprons). C: Wide #2 withaprons. D: Junior #13 (Pedodontic). E: Universal #1.

Amalgam Matrices

Amalgam matrices are made of very thin flexiblestainless steel available in either roll form or in bands.At times, the standard packaged matrix bands do not

provide the necessary length, width, or shape for aparticular cavity preparation. When this is the case, thedentist can cut the metal matrix strips to form theneeded band. Bands used with the Tofflemire retainerscompletely encircle the tooth. Matrix bands come inassorted sizes and shapes, as shown in figure 4-27. Themost commonly used band is the Universal or Straight#1 size. The Junior #13 is the smaller pedodonticversion of the #1 Universal. The Wide #2 and Junior#15, (which have extensions known as “aprons”) areused when additional length is needed for a preparationextending below the gingiva. A dentist usually preferscertain types of these bands over others. With practice,you should become very proficient in having thepreferred band on the appropriate retainer.

ASSEMBLING MATRICES

When multiple surfaces of the tooth are removedduring the cavity preparation, a matrix is used toapproximate the original surface and hold therestorative material in proper form and position until itsets. The type of matrices used depends on the type ofrestorative material placed. You will need to have theright type of matrix available and assembled ready foruse during the procedure.

Amalgam matrices are made of very thin, flexiblestainless steel available in either roll form or bands.The matrix band, retainer, and wedge are used incombination to form a temporary mold while thefilling material is being packed.

The matrix is assembled and placed before theamalgam is mixed. After the amalgam has beenpacked, the matrix and wedge must be removed beforethe final carving can be accomplished.

The most commonly used retainer is the universalstraight Tofflemire. Its components are shown infigure 4-28.

Figure 4-28.—Components of the matrix retainer.

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To assemble the matrix, hold the retainer in onehand with the slots in the guide posts and locking visef a c i n g u p w a r d . T u r n t h e l a r g e i n n e r n u tcounterclockwise to position the locking vise close tot h e g u i d e p o s t . T u r n t h e s m a l l o u t e r n u tcounterclockwise until the rod is not visible in thelocking vise slot. In your other hand, grasp the bandwith the ends placed evenly together. Place the edge ofthe band with the larger circumference (occlusal edge)into the diagonal slot at the vise end of the retainer.With the. band placed in this manner, the largercircumference is toward the occlusal surface and thesmaller circumference toward the gingiva, as shown infigure 4-29. Continue to ease the band through theinner guide post slot. As figure 4-30 shows, positionthe band through the left guide post for teeth on themandibular right or maxillary left quadrants. For teethin the mandibular left or maxillary right quadrants,position the band through the right guide posts. Turnthe outer nut clockwise until the rod tip presses firmlyagainst the band in the lock vise to secure the band.Turn the inner nut counterclockwise to increase thesize.

When the assembled matrix is placed over theprepared tooth, the slot opening of the retainer and thesmall circumference of the band are positioned toward

Figure 4-29.—Large and small circumferences of the band.

Figure 4-30.—Positioning the band to the right or left for theappropriate quadrants.

the gingiva, and the retainer is placed along the facialsurface of the tooth. The handle of the retainer extendsout of the oral cavity at the corner of the lips. Thedentist gently manipulates the matrix band into theinter-proximal space on either side of the tooth. Thedentist then places an index finger or thumb over theocclusal surface to hold the band in place and tightensthe band by turning the inner nut clockwise to fitsnugly around the tooth. At this time, the dentist maydecide to place a wedge along the side of the matrixband.

Wedges

Wedges are small, tapering, triangular pieces ofwood or clear plastic about 1/2 inch in length. Wedgesare available in various sizes, which may be colorcoded. They are either plain (straight) or anatomicallyshaped (fig. 4-31). Clear plastic anatomical wedgesare designed for use with light-cured materials.

material to the confines of the prepared cavity marginsand the band itself.

matrix band around the tooth may not always produce asnug fit. This leaves space through which condensedrestorative material can be pushed out to create anundesirable overhanging restoration. The dentist useswedges to force the matrix band or strip tightly againstirregular tooth surfaces to prevent these spaces. Thissnug fit then restricts the firmly condensed restorative

Since the general shape oftooth crowns varies, the

Matrix Removal

Because new restorations fracture easily, useextreme care when removing the matrix band. Toremove the matrix band and retainer, the dentist, first

Figure 4-31.—Wedges.

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gently manipulates the point of an explorer around theinside edge of the band. This contours the marginalridge of the restoration and removes the excessamalgam around the matrix band. The assistant willpass the dentist hemostats or cotton forceps to removethe wedge if one was placed. With the thumb or fingerover the occlusal surface of the restoration and matrixband , the ou te r and inne r nu t s a re tu rnedcounterclockwise to loosen the retainer from the band.After the retainer is removed, the remaining band iscarefully removed. A loose end of the band is graspedwith the hemostats or cotton forceps and gently rockedback and forth until the band comes out of theinterproximal space. Remove the band from the otherinterproximal space in the same manner.

PIN AMALGAM SET

Extensive decay or a cusp fracture results in theloss of a major portion of the tooth structure. Torestore such a tooth to its former healthy condition, thedentist may choose to rebuild the tooth. If the tooth is aposterior one, the dentist may use the pin amalgamtechnique. For a pin amalgam restoration, the dentistuses specif ic instruments. The pin amalgaminstruments are packaged in kits in which pin burs(drills), self-threading pins, and pin (hand) wrenchesare precision matched. It is extremely important tokeep the set together since there are a large variety oftypes and sizes. The pins are placed with a handwrench in the tooth preparation to anchor the amalgamor restorative material in place (fig 4-32). A pinbender is frequently used to bend or slightly adjust theposition of inserted pins. Follow the manufacturer'sinstructions before handling these materials.

FOUR-HANDED DENTISTRY

The goal of four-handed dentistry is to allow thedentist and assistant to function as a team in a seated

position with maximal efficiency and minimal strain.Four-handed dentistry, as it has been developed, notonly increases productivity, but also reduces stress andfatigue on the provider and assistant. Four-handeddentistry can be used in all of the specialty areas, and inoperative dentistry. It is discussed here becauseinstrument exchanges in operative dentistry requireyou to perfect this task. To be an effective dentalassistant in four-handed dentistry, you must know thecorrect zones and positions that you are in and whereyou are in relation to the patient and dentist. Alsocorrect passing and receiving of instruments andmaterials to the dentist is a task that must be practicedto work efficiently with the dentist.

ZONES AND POSITIONS

The position of the patient is determined by theprocedure to be performed. Most dental treatment isprovided with the patient in the supine position. Oncethe patient has been seated, the dentist and the assistantshould place themselves in the proper positions fortreatment. These positions are best understood byrelating them to a clock. In the clock concept, animaginary circle is placed over the dental chair, withthe patient’s head at the center of the circle. The circleis numbered like a clock with the top of the circle at 12o'clock. The clock, as shown in figure 4-33, is dividedinto four zones of operation:

Static zone

Assistant's zone

Transfer zone

Operator's zone

The use of these zones is the key to the efficientimplementation of the principles of four-handeddentistry. For right-handed dentists, seated to theright of the patient, the operator's zone is between 8and 11 o'clock, and the assistant's zone is between 2

Figure 4-32.—Using a hand wrench to place pins in a toothpreparation.

Figure 4-33.—Zones of operation for four-handed dentistry.

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and 4 o'clock. For left-handed dentists, seated to theright of the patient, the operator's zone is between 1and 4 o'clock position and the assistant's zonebetween 8 and 10 o'clock. Whenever the treatment siteis on the lingual surfaces of anterior teeth, the dentist(right or left-handed) generally uses the 12 o'clockposition.

The transfer zone is from 4 to 8 o'clock.Instruments and materials are passed and received inthis zone over the chest and at the chin of the patient.All instruments and materials are located in theassistant's zone.

The static zone, from 11 to 2 o'clock, is a non-traffic area where equipment, such as nitrous oxide,can be placed with the top extending into the assistant'szone. When an object is heavy, or material or aninstrument is objectionable if held near the patient'sface, you may pass or hold it in the static zone. As anexample, anesthetic syringes are sometimes passed tothe dentist in this area so that the patient will not bealarmed at the sight of the syringe. Part of this area canalso be used when the provider is positioned in the 12o'clock position as previously mentioned.

Dentists and dental assistants should sit with theirback straight and head relatively erect. This helpsprevent curvature of the spine. The patient should belowered to a position that places the treatment site asclose to the dentist's elbow level as possible. When thepatient is properly positioned, the dentist's eyes shouldbe 14 to 16 inches from the treatment site.

As the assistant, you should sit as close as possibleto the back of the patient's chair with your feet directedtoward the head of the chair. This position lets youreach the treatment site, hose-attached instruments,and instruments and materials from the mobile cart orinstrument tray without leaning, twisting, oroverextending your arms. In this position you are alsoable to observe the patient’s responses throughout theprocedure. Adjust your stool so that your eye level is 4to 6 inches above the dentist's eye level. Like thedentist, the assistant should sit in an erect position. Theassistant's chair may have a curved, movable armrest.This armrest may be adjusted in front to support thebody just below the rib cage. Using this armrest as abrace, you are able to lean slightly forward from thehips only. Place your feet firmly on the foot-supportring at the base of the assistant chair so that your feetare parallel to the floor. The mobile cart or instrumenttray should be placed toward the head of the patient'schair, and positioned to allow you easy access to theneeded instruments and materials.

PASSING AND RECEIVINGINSTRUMENTS AND MATERIALS

To increase production while reducing stress andfatigue of the dentist and the assistant, you and thedentist will need to work together as a team. You mustbe able to anticipate the dentist’s needs and fulfill thoseneeds without unnecessary delay. To accomplish this,you must know the sequence of the treatmentprocedure and have the required instruments andmaterials ready at the proper time. When you assist infour-handed dentistry, you must also irrigate with airand water as well as aspirate with the high-volumeevacuator throughout the procedure. To enable you topass and receive items efficiently during theprocedure, we will begin with instrument transfers.

Instrument Exchange

Instrument exchange between the dentist andassistant takes place in the transfer zone near thepatient's chin. As the assistant, you must anticipate thedentist's needs, and be ready when signaled by thedentist to pass the next instrument and receive the usedone in a smooth motion. An alert assistant does notneed a verbal command to make the exchange, butshould be constantly ready when the exchange signaloccurs . Idea l ly , the ins t rument t r ans fe r i saccomplished with a minimum of motion involvingmovement only of your fingers, wrist, and elbow.During the transfer, the dentist should not move thefinger rest or eyes from the treatment site. When theexchange is completed, the dentist pivots the workinghand back to the working position.

You should arrange the instrument setup in anorderly fashion. Usually the instruments are set upfrom left to right, in the sequence in which they are tobe used. You should return them to their originalposition following use in case they need to be reused.

Let's assume that you are assisting a right-handed dentist and, therefore, are seated on the leftside of a patient. Since your right hand is busyaspirating, you must learn to transfer instrumentswith your left hand. The one-hand instrumentexchange is discussed next.

ONE-HAND INSTRUMENT EXCHANGE.—The actual instrument transfer is divided into fourstages—working, signal, pre-transfer, and mid-transfer.

In the working stage, pick up the next instrumentto be used from the instrument tray with your left

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hand. Grasp the instrument between your thumb and

first two fingers by the end opposite from the working

end as shown in figure 4-34 (step A). Hold the working

instrument close to the treatment area and parallel to

the instrument being used. Extend your little finger to

receive the instrument being used by the dentist as

shown in figure 4-34 (step B). finger.

The signal stage takes place when the dentistsignals for the next instrument by slightly raising theinstrument from the tooth. During this stage, thedentist maintains his/her fulcrum (finger rest) and,with a pivotal action, rotates the working hand awayfrom the patient's oral cavity. This positions the usedinstrument so that vou can grasp it with vour little

Figure 4-34.—Instrument exchange (steps A through D).

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In the pre-transfer stage, grasp the used instrumentfirmly using the little finger as shown in figure 4-34(step C). Sometimes, you may prefer to use the last twoor even three fingers to receive the used instruments.Immediately following this action, you carry out themid-transfer stage.

In this stage, place the next instrument into thedentist's hand with the working end positioned towardthe treatment site, as shown in figure 4-34 (step D).When the treatment site is located on the maxillaryarch, point the working end of the instrument up.Likewise, when the treatment site is on the mandibulararch, position the working end down. Do not releaseyour grip of the new instrument until the dentist hasfirmly grasped the instrument. If the instrumentsbecome tangled during the exchange, this is usuallycaused by failure to parallel the handles before theexchange. The exchange of all instruments is donewith firm, deliberate movements to give both thedentist and the assistant the feeling of confidence andto eliminate lost time and motion. Return the usedinstrument to its original position on the instrumenttray and prepare to repeat the procedure with the nextinstrument required.

Refer to figure 4-35 for an overhead view (left-handed) of an instrument exchange during patienttreatment. When you assist from the right side of the

Figure 4-35.—Overhead view of instrument exchange.

patient, use your right hand in the same mannerdescribed for the left hand.

O T H E R I N S T R U M E N T E X C H A N G ETECHNIQUES.—Other instrument exchangetechniques may have to be used depending on whattype of instrument is being exchanged. These othertechniques have been described in "Oral SurgeryAssistance," Volume 2, chapter 5.

Handpiece and Bur Exchange

The dental handpiece can be exchanged foranother instrument in the same manner described inthis section. If two handpieces are exchanged, exercisecaution to avoid tangling the hoses during theexchange.

During the operative procedure, the dentist holdsthe handpiece firmly over the patient's upper chest inthe transfer zone, and then the assistant will loosen andremove the bur. The assistant next retrieves the burthat was selected by the dentist and places it into thedental handpiece and secures it. Always give the bur agentle tug to ensure that it is firmly seated in thehandpiece. If the dentist uses a different instrumentbetween bur exchanges, change the bur outside thetransfer zone, usually over the tray setup.

If the dentist changes handpieces and requires anexchange of burs in the returned handpiece, be sure touse the lock-out toggle switch for the handpiece beforeattempting to change burs. If you fail to do this, youcould cause harm to yourself when the provider stepson the foot control to activate the other handpiece.

Preparing and Passing Materials

Dental materials are exchanged at the patient'schin in the transfer zone. This prevents materials frombeing dropped on the patient’s face. Small amounts ofdental materials may be mixed and passed on a glassslab, paper pad, or dappen dish.

As a dental assistant, you must prepare dentalmaterials at the proper time during the procedure. Amaterial mixed too soon does not allow sufficienthandling time. Knowing when to mix is equally asimportant as knowing how to mix. As withinstruments, knowing the routine of the procedure letsyou anticipate when the dentist will need the specificmaterial. You should have the mixing equipmentready and the material in position and in place slightlybefore the time it is needed. Begin mixing only whenyou know the dentist is ready.

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When you are assisting during an amalgamrestoration, load the amalgam into the carrier and passthe loaded carrier to the dentist. You may sometimesuse two or more amalgam carriers, which lets you fillthe barrel of one while the dentist is using the other.You must also add into this sequence of filling andrefilling the amalgam carriers the passing ofcondensing instruments to the dentist during theamalgam restoration process.

During the use of cements, most dentists preferthat you leave the mixed cement on the glass slab ormixing pad and then hold the pad or slab in your handnear the treatment site. The dentist can select theamount desired. In your other hand, you can hold theair syringe to dry the area for application andplacement of the material. With the use of somematerials, you may need to hold a gauze sponge in yourhand (rather than the air syringe) to wipe excessmaterial from the application instrument.

The overall idea in passing and receiving dentalinstruments and materials is to have the needed item atthe right place, in the right position, at the right time. Indoing this, the dentist is then free to concentrate moreon the area of treatment.

BASIC DENTAL PROCEDURES

Some basic dental procedures, such as admini-stration of local anesthetic, irrigation, aspiration, andretracting of tissues, are performed in nearly all aspectsof all clinical dentistry. Others such as rubber damapplication and assembling of matrices are performedin operative procedures. Except for the administrationof local anesthetic, you must be able to perform theseprocedures. When administration of local anesthetic isrequired, you need to prepare all the items used for thisprocedure.

LOCAL ANESTHETIC

Before doing a possibly painful dental procedure,the dentist will give the patient a local anesthetic tomake the treatment site insensitive to pain. You mustbe knowledgeable of the various techniques used toprepare for the correct type of injection. Thesetechniques such as topical, infiltration, and blockinjections have been discussed in Volume I, chapter 7,"Oral Pharmacology."

Pre-Injection Items

Before giving a local anesthetic, the dentist mayuse the following pre-injection items to prepare theinjection site:

Antiseptic solution

2 x 2 inch gauze sponges

Cotton tip applicators

Topical anesthetic

The dentist may have the patient use an antisepticmouthwash to rinse the oral cavity before applying atopical anesthetic. The gauze sponges are used to drythe injection site mucosa before applying the topicalanesthetic. The topical anesthetic, usually supplied inan ointment, is applied with a cotton tip applicator toreduce the pain associated with the injection of theneedle.

Injection Items

The items used to give local anesthetics are anaspirating syringe, needle, and carpule. It is alsoimportant to know the different types of anesthetic andhow to assemble and disassemble the aspiratingsyringe properly for the dentist's use.

You'll find many types of anesthetic carpules inNavy dentistry. As discussed in Volume I, chapter 7,"Oral Pharmacology," the two most common localanesthetics used in dentistry are 2% lidocainehydrochloride and 2% mepivacaine. Each type ofanesthetic is sealed in a 1.8-cc glass carpule. Theneedle end of each carpule is sealed with rubbermembrane held in place by a metal band. The other endhas a different colored rubber stopper. Each type ofanesthetic has a different colored rubber stopper.

Assembling An Aspirating Syringe

Based on the patient's health history and theprocedure to be performed, the dentist will inform youwhich type of anesthetic (including vasoconstrictorcontent), needle length, and needle gauge to use toprepare the syringe. You will become familiar witheach dentist's preference and various procedures forneedle length and gauge. However, always verify thetype of anesthetic solution. Assemble the syringe outof the patient's view to reduce unnecessary patientapprehension. Assembly can be done while the dentistadministers the topical anesthetic.

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First, always check the carpule for cracks orsuspended articles floating in the solution. If you findany, discard the carpule and notify the dental anddental supply to ensure other batches of anesthetic areusable. Disinfect the rubber diaphragm on the carpulebefore loading it in the syringe. Do not touch therubber diaphragm after you disinfect it. Placing thecarpule end in the aspirating syringe is fairly easy. Usethe following steps:

Use the thumb ring to pull the plunger backagainst the syringe body.

Place the cartridge into the barrel of the syringewith the rubber stopper end in first, positioned towardthe plunger.

Break the seal on the needle container andremove only a small portion of the plastic needle cover.

Insert the needle into the syringe and screw thehub onto the syringe.

ring with your other hand.

Engage the harpoon into the rubber stopper of thecartridge by holding the body portion of the syringewith one hand while lightly tapping the end of the thumb

CAUTION

Do not tap the thumb ring with too much force;

this might cause the glass carpule to shatter.

Make a quarter turn with the thumb ring toensure that the harpoon is firmly engaged in therubber stopper. If it is, the thumb ring will rotateback to its original position.

Force a small, but visible amount ofanesthesia through the needle to expel air.

Loosen the needle cap, but keep the plasticneedle covering in place until you pass the syringe tothe dentist to guard against possible contamination.

The plastic needle cover must be removed tocheck the syringe's operation and during theinjection.

Passing and Receiving the Syringe

The dentist will be ready to administer the localanesthetic after the topical anesthetic is applied. Theassistant passes the syringe with the needle cover inplace. Hold the barrel of the syringe in your hand.Place the thumb ring of the syringe over the dentist'sthumb and the finger grip between the dentist's index

and middle fingers. While you are still holding thesyringe by the barrel, use the other hand to remove theneedle cap.

After the dentist gives the injection, carefullyremove the syringe by grasping the barrel and liftingthe syringe out of the dentist's hand. Remember toexercise extreme caution when grasping the barrel ofthe syringe because the needle is exposed andcontaminated. DO NOT attempt to recap the needlewhile the syringe is in the dentist's hand. If it isnecessary to recap the needle, it must be done usingsome type of mechanical device or the one-handedscoop technique discussed in Volume I, Chapter 9,"Infection Control."

Disassembling the Aspirating Syringe

After the patient is dismissed, the syringe must bedisassembled safely. It is vitally important to preventneedle sticks from the contaminated needle. It isadvisable to first remove the carpule with the needleremaining in place. This provides an air vent toprevent the glass carpule from shattering. To unloadthe carpule, pull the piston rod back as far as possible todisengage the harpoon from the rubber stopper withoutpulling the stopper from the carpule. The carpule canthen be easily removed from the syringe. Remove theused needle and dispose of it into a puncture-resistantcontainer according to established infection controlstandards.

IRRIGATION AND ASPIRATION

Immediately after the dentist administers the localanesthesia, you will irrigate and aspirate the injectionsite. This is necessary because the anesthetic solutionproduces a bitter taste in the patient's mouth.Additionally, you are required to irrigate and aspirate(drawn by suction) often throughout the treatmentprocedure to maintain a clean treatment site.

Irrigation

The dentist expects you, as the dental assistant, toirrigate the oral cavity when necessary. By applyingwater or saline solutions to the treatment site in the oralcavity, small tooth particles, dried blood, and otherdebris are flushed from the area and removed byaspiration. Handpieces with water spray systemsprovide some irrigation, but additional irrigation isalways necessary. At times, the dentist may decide notto use the water spray system on the handpiece for aparticular procedure. During routine operativeprocedures, you will use the three-way syringe on the

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dental unit to irrigate the treatment site with water orwater spray. The tip of the three-way syringe rotateseasily to direct the water, spray, or air at the specifictreatment sites. The tip disconnects to allow forsterilization.

When you irrigate treatment sites during surgicalprocedures, you will use a sterile saline solution orsterile water as the irrigation solution. Sterile saline orsterile water is applied by using a bulb-type or Luer(piston-barrel) syringe. The main purpose forirrigation during surgical procedures is to keep a cleantreatment site. The cleansing is not complete until theirrigating solution is aspirated from the mouth.

Aspiration

Aspiration is necessary to remove blood, pus,saliva, and debris from the treatment site and oralcavity. This is done by using the high-volumeevacuator (HVE) or saliva ejector. Figure 4-36illustrates the reverse palm grasp and modified pen.grasp that should be used when you are using the HVE.As the dental assistant, you must assure that a sterile ordisposable tip is in place for each patient. When usingeither of these, always place the tip in the uprightposition before turning the aspiration off. This helpsprevent materials from dripping out or clogging thehoses. You must also clean and maintain theevacuation system as instructed in the manufacturer'soperation and maintenance instructions.

Figure 4-36.—Reverse palm grasp and modified pen grasp

using an HVE.

OPERATIVE PROCEDURES

Operative dentistry strives to restore decayed orfractured teeth to their original functional ability andesthetic quality of healthy dentition. In general,procedures include the following:

Determining the procedure to be done

Administering anesthesia

Placing a rubber dam

Preparing the cavity or cavities to be filled

Placing filling material into prepared cavitypreparations

Carving and finishing restorations

Smoothing and polishing restorations

As an assistant in operative dentistry, you willperform many of the basic clinical proceduresdiscussed earlier, such as:

Preparing the dental treatment room (DTR)

Performing proper infection control procedures

Wearing appropriate personal protectiveequipment

Selecting and arranging instruments andmaterials required for the procedure

Receiving and preparing the patient

Preparing local anesthetic

Irrigating and aspirating throughout theprocedure

Retracting tissue to maintain a clear field ofvision

Preparing and assisting with the placement of therubber dam

Preparing, passing, and receiving instrumentsand materials

Figure 4-37 illustrates a typical selection andarrangement of instruments for a routine operativeprocedure. Items should be arranged in sequentialorder of the procedure to proceed smoothly withoutdelay.

TERMINOLOGY AND CLASSIFICATIONOF CAVITIES

For the necessary treatment procedures to proceedsmoothly and without delay, you need to understandsome basic terminology and classification of cavities.

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Figure 4-37.—Typical operative dentistry instrument tray setup.

A cavity preparation is a mechanical procedurethat removes caries or existing restorative materialsand a limited amount of healthy tooth structure toreceive and retain restorative materials in the cavitypreparation. A cavity wall is a side or surface of thecavity preparation that aids in enclosing the restorativematerial. You should already be familiar with theterms used to describe the various tooth surfaces, suchas mesial, distal, lingual, facial, incisal, and occlusal.A bevel is a slanting of the enamel margins of the tooth

preparation cut at an angle with the cavity wall. Thereare numerous types of bevels, such as full, long,chamfer, and dovetail.

Cavities can occur on one or more surfaces, andcan be of various sizes, ranging from very small tothose that include all five surfaces of the tooth. Simply,cavities are those which occur on one surface of thetooth. When two surfaces of the tooth are involved, thecavity is called a compound cavity. A cavity is

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considered a scomplex cavity when three or moresurfaces are involved. Compound and complexcavities may include one or both of the proximalsurfaces as well as portions of the facial and lingualsurfaces. When caries attack the proximal surfaces ofposterior teeth, the cavity preparation must alsoinclude preparation of the occlusal surfaces.

Cavities may be classified according to thelocation where the carious lesion begins. Cariesfrequently start in the developmental pits and fissuresof the teeth. These areas are deeper than thesurrounding tooth substance and are nearly impossibleto clean thoroughly, creating ideal conditions forbacterial plaque formation. Locations of pit andfissure caries can be located in any of the followingareas:

Lingual pits of maxillary incisors

Lingual grooves and pits of maxillary molars

Occlusal surfaces of posterior teeth

Facial grooves and pits of mandibular molars

Pits occurring in areas because of irregularitiesin the formation of enamel

Smooth surface cavities can be found on all teethon the proximal surfaces, and gingival one-third of thefacial and lingual surfaces.

STEPS IN CAVITY PREPARATION

After the dentist decides which tooth or teeth torestore, the anesthesia is administered and the rubberdam placed. If you are well prepared, the steps in thecavity preparation should proceed smoothly withoutdelay, and the patient will be more at ease andconfident. Watch closely during the procedure and beready to irrigate and aspirate as needed, as well as, passthe instruments and material to the doctor whenneeded. The initial cavity preparation generally isdone using the high-speed handpiece and a variety ofrotary instruments.

Cavity Design

The design of the cavity preparation for either atooth with initial caries or replacement restoration isbased on the location of the caries, the amount andextent of the caries, the amount of lost tooth structure,and the restorative material to be used.

Some basic principles should be considered whenpreparing a cavity preparation. The dentist must

establish an outline form, which determines theoverall shape of the preparation along the cavitymargins of the restoration and the tooth surfaces. Theoutline form is determined by the size and shape of thecarious lesion and by the need for a suitable design thatwill hold a restoration firmly in place. Usually, thedentist is able to visualize the shape of the completedcavity before cutting the preparation by viewing theextent of the caries on the radiograph and examiningthe tooth and soft tissues.

Removal of Remaining Caries

Carious dentin not removed during the design ofthe cavity preparation is removed by using either roundburs or spoon excavators. When the dentin has a firmfeel with the explorer, removal of the tooth structureshould cease, even if stained dentin remains.

Finishing the Enamel Walls and Margins

The last cutting step in the preparation of the cavityis finishing the enamel walls. This is a process ofangling, beveling, and smoothing the walls of thecavity preparation to achieve the best marginal sealpossible between the restorative material and toothstructure. The dentist may use burs, diamond stones,or hand-cutting instruments (chisels, hoes, hatchets,and gingival margin trimmers) to complete the wallsby removing loose or unsupported enamel to create thestrongest possible enamel wall.

Cleansing the Cavity

The final step in cavity preparation is cleansing thecavity. This includes the removal of accumulateddebris, drying the cavity, and final inspection beforeplacing restorative materials. All debris must beremoved from the cavity, especially on the margins,because deposits left on them subsequently dissolve,resulting in a leak that invites recurrent caries.

Irrigating the cavity preparation with warm waterusually removes all debris. Stubborn particles of

debris may be removed with a small cotton pelletdampened with water or hydrogen peroxide.Following irrigation and aspiration to remove thedebris, the cavity must be dried thoroughly withpressurized air from the 3-way syringe or dry cottonpellets.

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Placement of Restorative Materials

After the cavity preparation is completed, yourattention as the assistant is especially critical. Youmust rapidly anticipate each step in the procedure tohave the necessary material ready at the proper time.You must prepare and pass restorative materials, mixthem at the right time, and follow the manufacturer'sinstructions. More instruments are needed to place therestoration than to prepare the tooth; therefore, moreinstrument transfers are necessary and occur morerapidly than in cavity preparation. Once the restorativematerials have been placed in the oral cavity, thedentist then begins to finish the restoration.

C A V I T Y L I N E R S A N D B A S E S .—Mostdentists use some type of cavity liner or base in almostall cavity preparations. They are used primarily toprotect the pulp and to aid the pulp in recoveringfrom irritation resulting from cavity preparation.Liners and bases are placed when the cavitypreparation is completed, just before insertion of therestorative material.

Glass ionomer cements and dentin bonding agentsare used primarily to seal the dentin and protect thepulp from bacterial invasion. Calcium hydroxide canbe used in extremely deep areas as an antibacterialagent and/or as a pulp capping material.

Most bases are applied best when the assistantwipes the instrument clean between each smallapplication. You will hold a gauze sponge in thetransfer zone and quickly wipe the end of theinstrument as the dentist moves toward the base mix. Ifthe dentist inadvertently gets the base on the enamelwalls of the cavity preparation, you will pass aninstrument for removal of the material.

Cavity varnish is a liner used to seal the dentinaltubules to help prevent microleakage and is placed in acavity to receive amalgam alloy after any bases havebeen placed. Cavity varnish is being used less and lesswith amalgam restorations, and dentin bonding agentsare replacing cavity varnish as the liner of choice.Cavity varnish has an organic solvent of ether orchloroform that quickly evaporates, leaving the resinas a thin film over the preparation. This varnish shouldbe slightly thicker than water. If it becomes very thick,discard it. Cavity varnish is not used with compositessince the varnish retards the set of composites andinterferes with the bonding of composites.

A small cotton pellet held by cotton forceps isdipped into the varnish just enough to wet the pellet.

The cavity varnish is applied to the pulpal area, wallsof the cavity preparation, and onto the edge of themargins of the preparation. Any excess varnish can beremoved from the enamel with a fresh cotton pellet. Asecond application of cavity varnish is placed over thefirst to thoroughly coat the surfaces of the dentin andfill any voids from bubbles created when the firstapplication dries. After liners and bases are placed intothe cavity preparation, the tooth may be restored withmaterials, such as amalgam, composite resin, or glassionomer.

AMALGAM RESTORATIONS.—Amalgam isused as a restorative material on the surfaces of bothpermanent and primary teeth. Amalgam also isaesthetically acceptable for distal restorations of thecuspid when the restoration is not readily visible.Amalgam can also be used to prepare a sound base for atooth before the preparation of a full artificial crown.This is commonly referred to as an amalgam buildup.

When multiple surfaces of the tooth are removedduring the cavity preparation, a matrix is required toapproximate the original wall and hold the restorativematerial in proper form and position until it sets.During the final stages of the cavity preparation, if notsooner, you should acknowledge the need for thematrix band and assemble it. While the liner and basematerials set, the dentist places the assembled matrixband and retainer around the tooth, along with wedgesif needed. Figure 4-38 illustrates a properly contouredand wedged matrix band.

While the dentist makes the final adjustments tothe matrix, you will need to ensure the precapsulatedamalgam is placed securely in the amalgamator andready to tr i turate (mix). The operat ion andmaintenance of the amalgamator is discussed inchapter 11, Volume 1, under Dental Equipment. Waitfor a signal from the dentist to begin mixing the

Figure 4-38.—Properly contoured and wedged matrix band.

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amalgam. When the amalgamator stops, remove theamalgam capsule for the amalgamator, open thecapsule, and empty the mixed amalgam into theamalgam well. Use caution with the amalgam mixbecause any moisture contamination causes thefinished restoration to expand. Load the amalgam intothe amalgam carrier (fig. 4-39). Some dentists permitthe assistant to dispense the amalgam into the cavitypreparation. Other dentists prefer to have you pass theloaded amalgam carrier and dispense the amalgamthemselves. In either case, you must pass the amalgamcondenser to the dentist. The dentist uses thecondenser to pack the amalgam firmly into all the areasof the prepared cavity. During the condensingprocedure, the dentist indicates when a change ofcondensers is needed. As you gain experience, youwill know wh en a change is needed by observing thestage of completion. The exchange of amalgam carrierand condensers continues until the cavity preparationis slightly overfilled. When the condenser is used forthe last time, the dentist may use a burnisher and or anexplorer on the restoration before removing the matrixband.

The dentist uses a burnisher to bring any excessmercury from the amalgam placed to the top of therestoration. Next the explorer is used to slightlycontour the restoration between the tooth and the bandbefore removal of the matrix and retainer. For dentistswho choose to initially carve the occlusal anatomy intothe restoration before removal of the matrix, have anamalgam carver ready to pass when you receive theexplorer. You will also need to have the cotton forceps

Figure 4-39.—Loading amalgam into the amalgam carrierfrom amalgam well.

or hemostat ready to pass when the dentist is ready toremove the wedge, retainer, and matrix band.

The dentist uses an interproximal carver to smooththe gingival margin of the amalgam restoration at theinterproximal area. Only the excess amalgam isremoved near the gingival margin to allow theproximal contact to be retained. The dentist continuescarving the proximal surfaces to conform to thecontour of the inter-proximal area of the tooth. Thedentist uses another carver, such as the discoid-cleoid,to carve the primary grooves on the occlusal surfaceand remove excess amalgam. You may need to haveanother carver ready to pass to the dentist to carve thefacial and lingual margins of the amalgam, ifapplicable. In addition to passing and receiving avariety of carvers to the dentist, you will need the high-volume evacuator (HVE) tip in your other hand toaspirate the shavings from the carving procedure atvarious times. When carving the amalgam restorationis completed, remove the rubber dam. Irrigate andaspirate the patient’s mouth and check the occlusion ofthe new restoration for any needed adjustments.

Have the articulating paper ready for use byplacing it into a hemostat or articulating paper holder.Pass this to the dentist to check the occlusion of therestoration. The articulating paper is placed in theteeth of the opposing quadrant and the patient isinstructed to gently close the teeth together. If thepatient closes the teeth together too suddenly or withtoo much pressure, the new amalgam restoration willfracture if it is too high. Have an amalgam carver readyto pass to the dentist to reduce any high spots on theamalgam restorations. The restoration is checked withthe articulating paper and carved until the properocclusion is obtained. Have a burnisher, such as a ballor ovoid, ready to pass to the dentist to burnish theamalgam restoration. When the restoration iscompleted, the oral cavity is irrigated and aspiratedusing the water syringe. Use the HVE to removeamalgam shavings resulting from the occlusaladjustment. Before dismissal, ensure the patient isgiven the postoperative instructions and understandsthem.

MERCURY CONTROL PROGRAM FORDENTAL TREATMENT FACILITIES.—Alldental personnel will follow BUMEDINST 6260.30because of the health hazard potential of mercury. Thisinstruction discusses control procedures for thehandling and disposal of amalgam or mercury-contaminated items and is discussed in Volume I,Chapter 11, "Dental Safety and Equipment."

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FINISHING AND POLISHING AMALGAMRESTORATIONS. —When amalgam restorationsare placed in the tooth, finishing and polishing of therestorat ions general ly take place at anotherappointment. The appointment should be at least 24hours after the placement of the amalgam. Polishingthe amalgam smooths the surface so that plaque doesnot adhere to it readily and makes the restoration lookmore attractive. The dentist checks the margins andproximal contacts of the restoration initially. A metalfiling strip can be used to remove any roughness oroverhand of the restoration in the proximal area. Thedentist may use finishing burs or stones in thehandpiece, followed by discs and abrasive points.Before use, discs may be coated with a lubricant, or insome cases, wet with water. The abrasive pointsprogress from a more-abrasive to a less-abrasive pointuntil a smooth mirror-like surface is obtained on theamalgam restoration. Extra-fine pumice and dry tinoxide, or commercial silicone-mounted polishingcups, may be used for a final polishing.

COMPOSITE RESIN RESTORATIONS.—The restoration of tooth surfaces that are normallyeasily visible are restored with tooth-coloredrestorative materials for an esthetic appearance. Oneof the most commonly used tooth-colored restorativematerials is the composite resin. The three types ofcomposite resins available are

macrofilled,

microfilled, and

hybrid.

The classification of each composite resin dependson the particle size of its inorganic filler. Themacrofilled and hybrid resins have higher amounts ofinorganic fillers and lower amounts of organic resinthan the microfilled resins. This provides the strengthneeded for proximal-incisal restorations. Theserestorations may be prepared with or without the pinretention technique. On the other hand, becausemicrofilled resins have a smaller particle size, they areeasier to polish than macrofilled resins. Many of therecently developed hybrids achieve good polishabilityand esthetics—one reason for their increasedpopularity.

Composite resin materials are available in self-curing two-paste systems and light-curing single-paste systems. Some brands offer several colorselections; whereas, others are supplied in a universalshade. The shade must always be selected before the

teeth are allowed to dry because dehydration results inlighter shades.

The restorative material is retained in the cavitypreparation by mechanical retention. Chipped orfractured teeth rely mostly on acid-etch enamel forretention of the restorative material. Acid-etching theenamel portion of cavity preparations with a 35 to 50percent solution of phosphoric acid results in improvedretention for resin restorations. A celluloid matrix maybe placed before the acid-etching procedure to protectthe adjacent teeth. The phosphoric acid is applied tothe enamel surface of the cavity preparation and isallowed to be in contact with the enamel for 1 minute.Then the area is rinsed thoroughly with water anddried. The etched enamel surface, when dried, appearschalky white because of a slight dissolving of thesurface enamel that leaves microscopic undercuts(retention). After etching the tooth, a bonding agent isapplied.

The dentist may need an instrument to pack thecomposite resin material into the cavity preparationand to avoid formation of air bubbles. When thecomposite resin material is applied to the etched andbonded surface, the resin invades the surface void,undercuts, and irregularities. When surfaces in theproximal area are restored, the dentist will place acelluloid matrix that will assist in preventing thecomposite material from adhering to adjacent teeth andalso acts as a form to properly place the material (fig 4-40). If using a light-cured system of composite resin,the light source is positioned near the restoration andexposed according to the manufacturer's instructions.These light-curing systems are discussed in Chapter11, Volume I, "Dental Safety and Equipment." Thedentist, assistant, and the patient should wearprotective glasses during the light exposure.

Once the resin material cures, a mechanical bondforms. This type of surface union between therestorative material and the enamel improves theretention qualities and provides a smoother cavity

Figure 4-40.—Using a celluloid matrix for a proximalcomposite restoration.

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margin, improving the esthetics of the restoration. Inaddition, less marginal leakage is likely to occurbecause of the improved union of the enamel andrestoration.

To finish the restoration, the matrix is removed andany rough areas are smoothed with composite-typefinishing burs. If the restoration involves proximalsurfaces, abrasive strips similar to those shown infigure 4-41 are used to smooth these surfaces. Ifapplicable, the gingival margin of the restoration ischecked to remove any excess composite material.The surface of the restoration is smoothed further witha fine and an extra-fine disc of silicon carbide andzirconium silicate. These smooth surfaces preventretention of food debris or plaque. If a higher gloss ofthe facial surface is desired, a coating of sealantmaterial is placed over the finished restoration. Aftercompletion of the restoration, the rubber dam isremoved and oral cavity irrigated and aspirated. Ifnecessary, the dentist checks the occlusion and makesadjustments.

GLASS IONOMER RESTORATIONS.—Usually, the gingival areas on the facial aspect of themaxillary anterior teeth are restored with one of thetooth-colored restorative materials for an estheticappearance. Restorations located on the gingival thirdof the tooth may be necessary because the tooth iscarious or because it has been worn away or abraded byincorrect brushing habits. Since glass ionomercements bond directly with enamel, dentin, andcementum, they may be used for such restorationswhere minimal preparation of the tooth is desired, orwhere the fluoride release from the cement is desired toresist recurrence of caries. During placement of theglass ionomer cement restoration, the cavity area mustbe kept totally dry because moisture will cause afailure of the restoration.

SUPPLY PROCEDURES

A competent dental assistant can increase theefficiency, productivity, and reduce the operational

Figure 4-41 .-Using an abrasive strip to finish a proximalsurface.

costs in a DTR by using proper supply procedures. Itcosts time and money to run out of necessary items. Itis also wasteful and expensive to order and store itemsthat are never used.

You will use a supply catalog to order supplies.Some facilities make up a catalog for local use, listingfrequently ordered items.

To order an item, look it up in the catalog and thenfill out the appropriate "request for issue" form. Theseforms may vary slightly in format but they all requirethe same basic information. It is important that you fillout the form accurately and completely. It is importantto know item nomenclature, identification, anddistribution data.

When your supplies arrive, check the items againstyour order form to ensure you receive the items andquantities that you ordered. Also check broken seals orloose parts. If you discover anything out of theordinary, notify your supervisor. After supplies havebeen checked, store them in a manner consistent withthe manufacturer's instructions to prevent spoilage ordamage.

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CHAPTER 5

ORAL SURGERY ASSISTANCE

INTRODUCTION

Oral surgery deals with the surgical treatment orcorrection of diseases, defects, or injuries of the oralcavity, teeth, and adjacent tissues. A sound knowledgeof surgical assisting procedures is essential if you areto be an effective oral surgery assistant.

ORAL SURGERY FUNCTION

Oral surgery provides surgical treatment orcorrection of diseases, defects, or injuries of the oralcavity and facial structures. A wide variety of surgicalprocedures takes place in the oral-maxillofacialsurgery area. Exodontics is the term used to describethe extraction of teeth in oral surgery. General dentistsare trained in surgical procedures; however, they maychoose to refer the patient with a more complicatedcase to an oral surgeon who has specialized training inthe area. A maxillofacial surgeon is an oral surgeonwho specializes in the reduction of bone fractures andreconstruction of the maxilla or mandible, andperforms reconstructive surgery.

INDICATIONS ANDCONTRAINDICATIONS

Before a surgical procedure can be done, the oralsurgeon will evaluate each patient's record forindications and contraindications to treatment. Someindications for oral surgery include:

Carious teeth unrestorable by restorativeprocedures.

Nonvital teeth when endodontic treatment is notindicated or has little chance of success.

Removal of teeth to provide space in the arch fororthodontic treatment.

Teeth without sufficient bone support.

Supernumerary or impacted teeth interferingwith normal dentition.

Malpositioned teeth that cannot be aligned.

Root fragments from prior extractions orsurgery.

Removal of soft-tissue.

Removal of exostosis (overgrowth of bone),such as torus mandibularis and torus plantinus.

Accidental fracture or reconstruction of themandible or maxilla.

The oral surgeon will also evaluate the patient forpossible contraindications to surgical treatment.Extractions should be avoided when an activeinfection is present because local anesthesia is difficultto achieve and the infection can spread to other parts ofthe body. Patients suffering from any potentiallyserious disease, such as heart disease, diabetes, andblood disorders, should first be evaluated by aphysician to determine if they can withstand theprescribed treatment. Patients in the early stages ofpregnancy should have the surgery postponed untilthey are in the second trimester.

EXAMINATION AND INFORMEDCONSENT

Examination and informed consent are essential todetermine what treatment is required, and provide allrelevant information to the patient to make aninformed decision regarding proposed treatment.

Examination

The oral surgeon examines the patient to confirmthe findings of the referring dentist and gather anyother additional information to make treatmentrecommendations. Oral surgeons should orderradiographs of the teeth, mandible, maxilla, or otherfacial areas to verify the treatment recommendations ifnot already taken. The radiographs may includeperiapical, extraoral of the skull or facial aspects,panoramic, temporomandibular, and occlusal. Acomprehensive medical history review is essential forthe surgical patient because of the strain surgery placeson the body. If there are any questions regarding thepatient's health or ability to withstand surgery, thesurgeon should consult with the patient's physicianbefore surgery. During the examination, the oralsurgeon also discusses appropriate pain-controlmethods for the surgical treatment recommended, andinformed consent with the patient or legal guardian.

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Informed Consent

Providing proper informed consent is an integralpart of appropriate patient-provider relations. Dentalproviders should make every attempt to disclose allrelevant information to the patient or legal guardian in

order for them to make an informed decision regardingany proposed treatment. The Standard Form 522,Request for Administration of Anesthesia and forPerformance of Operations and other Procedures (fig.5-1) should be used when informed consent isrequired, including the use of intravenous conscious

Figure 5-1.—Request for Administration of Anesthesia and for Performance of Operations and Other Procedures, SF 522.

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sedation or general surgery, and certain oral orperiodontal surgery procedures. Most routineinformed consent can be easily accomplished duringthe verbal verification of diagnosis and treatmentpresentation.

PAIN AND ANXIETY CONTROL

When dental surgery is indicated, whether oral orperiodontal, there are several pain and anxiety controlmethods available to make the surgery as smooth aspossible and put the patient at ease. The three basiclevels of anesthesia are local, conscious sedation, andgeneral. You should review Dental Technician,Volume 1, Chapter 7, "Oral Pharmacology," to helpyou better understand the following information

Local Anesthesia

The primary effect of local anesthetic agents is topenetrate the nerve cell membrane and block theconduction of nerve impulses from the point where thelocal anesthetic is active. This produces anesthesia inthe local area. Local anesthesia, using infiltration,nerve block, or a combination of both techniques, isused in surgery cases to numb the surgery area.

Most dental surgery procedures require two ormore injections of a local anesthetic. For this reason, itis a good practice to include two aspirating syringeswith each instrument setup. This will let you supplythe dentist with a loaded anesthetic syringe for as longas needed with minimum loss of time. Since anestheticsolutions are bitter and there is leakage from theinjection sites, you will need to irrigate and aspirate thefluids from the patient's mouth after injection.

Conscious Sedation

Conscious sedation is a minimally depressed levelof consciousness that retains the patient's ability toindependently and continuously maintain an airway,and respond appropriately to verbal commands.Conscious sedation involves using various drugs or acombination of drugs to achieve pain and anxietycontrol while maintaining the patient in a consciousstate at all times. The common routes of administrationof conscious sedation are oral premeditation,inhalation, and intravenous. Local anesthesia isadministrated with all types of conscious sedation.

General Anesthesia

General anesthesia is a controlled state ofunconsciousness accompanied by a partial or complete

loss of protective reflexes, including the ability tomaintain an airway independently and respond toverbal commands. General anesthesia renders thepatient unconscious through depression of the centralnervous system, thus eliminating patient cooperationas a factor. The administration of general anesthesia isperformed by an anesthesiologist in the hospitaloperating room. Local anesthesia is also administeredat the treatment site.

ORAL SURGERY PROCEDURES

While there are many oral surgery procedures,some are more commonly performed than others. Youshould be knowledgeable of those that are commonlyperformed. In the following paragraphs, we discusssurgical procedures you will need to know.

TOOTH EXTRACTIONS

Tooth extraction is an oral surgery procedureclassified into three types: simple, complicated, andimpacted extractions. These are explained briefly inthe following paragraphs.

Simple Extractions

Simple extractions involve removal of a tooth orroot that does not require bone removal or sectioning.The deciduous (nonpermanent) or permanent toothextracted is erupted and usually diseased or malposed.Retained roots may be buried in the tissue and notvisible in the oral cavity. Retained root tips may bepresent because of fractured teeth, advanced decay, orany incomplete post-surgical procedure. They can beidentified on radiographs.

Complicated Extractions

Complicated extractions involve removal of atooth or root that requires surgical sectioning and/orbone removal.

Impacted Extractions

Impacted extractions involve removal of a tooththat is partially or completely covered by bone and orsoft tissue. This extraction may involve tissueincision, excision, or bone removal. Two types ofimpactions are associated with oral surgery: soft tissueand bony impaction.

Soft tissue—occurs when the tooth is blockedfrom eruption due to the gingival tissue. It may bepartially erupted with a portion of the tooth visible in themouth.

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Bony impaction—occurs when the tooth isblocked by both bone and soft tissue. The soft tissuemust be removed to gain access to the tooth before it canbe extracted. The oral surgeon removes the alveolarbone over the impaction using a bur or chisel and mallet.Removal of the bone provides access for elevators orextraction forceps to extract the tooth. A surgicalhandpiece with a bur may also be used to section thetooth into four pieces and then each piece is removedseparately. A commonly performed impactedextraction is the removal of unerupted third molars.

ALVEOLOPLASTY

Alveoloplasty involves contouring the alveolarstructures. It may be done in conjunction with multiplesurgical extractions to eliminate sharp bone edges thatcould cause discomfort to the patient, and to providesuitably contoured bone structure for denturefabrication and insertion. An alveoloplasty may alsobe performed to contour the bone without being inconjunction with extractions.

OSTEOTOMY

Osteotomy literally means cutting away of bone.Osteotomies include maxillofacial surgery performedto modify or correct facial abnormalities, such asprotrusion of the mandible or maxilla where the bone isplaced as far forward as possible, or retrusion of themandible or maxilla where the bone is placed as farback as possible. The oral surgeon may also performan osteotomy on a patient who has a fracturedmandible or maxilla. The patient's teeth are splinted tobind them together into one unit using arch bars, elasticbands, and interdental sutures using wire. This keepsthe bones in place, while they heal into the correctposition. After healing takes places, the splint andwiring are removed.

EXOSTOSIS

Exostosis is the surgical removal of bony growthsprojecting past the normal contour of a bony surface. Itincludes torus mandibularis often found on thelingual surfaces of the body of the mandible, and toruspalantinus located on the center of the hard palate.Usually, tori removals are performed to permitfabrication and insertion of dentures, or to improvespeaking or eating functions.

FRENECTOMY

A frenectomy is a surgical procedure used toremove a malattached facial or lingual frenum. A

frenum is the tissue that attaches the tongue, cheeks,and lips to the alveolar process of the upper and lowerjaw. The malattached tissue restricts movement of thetongue (lingual frenum) or lips (labial frenum). Thefrenum may be removed, loosened, or repositioned.The excision of the lingual frenum is done to helpcorrect a condition known as tongue-tie. The labialfrenum may require surgery to enable better lipmovement, and to help prevent large diastemas(spaces) between erupting central incisors.Frenectomies are commonly performed on children.

BIOPSY

A localized area of abnormal tissue is referred to asa lesion. A biopsy is a surgical procedure to remove apiece of tissue from the lesion for diagnostic andmicroscopic examination. The information obtainedfrom a biopsy procedure assists the dentist in arrivingat a diagnosis and predicting the prognosis of thedisease. It is common in dentistry to remove bothnormal and abnormal tissue from the surgical site forcomparison.

The tissue specimen should be handled carefully toprevent crushing or tearing. Immediately place it into aspecimen bottle containing a sufficient amount of 10percent of buffered formalin to preserve it. Beforesubmitting the specimen, ensure that the bottle istightly closed and labeled properly. At a minimum, thelabel should include the patient's name, age, sex, andthe dentist's name, your command’s name, and the dateof the biopsy. The dentist will include a TissueExamination, SF-515 Form, with the specimen alongwith a tentative diagnosis that is sent to an oralhistopathology center. If the histopathology report ofan oral biopsy has a premalignant or malignantdiagnosis, the dentist must notify the patient of theresults. Two common biopsy methods used indentistry are incision and excision methods.

Incision Method

The incision method involves the removal of asample of the lesion for examination. A wedge-shapedsection of the tissue from the lesion along withadjacent normal tissue is removed for comparison.The biopsy site is sutured and the patient is dismissed.

The incision method generally is used when thelesion is large or in a strategic area where completeremoval of the lesion would create significant estheticor functional impairment. Complete surgical removalof the lesion is not indicated until a final diagnosis is

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made. If the lesion is not malignant, it is allowed toheal without further surgery. If a laboratory test showsthe tissue is malignant, complete removal is indicated.

Excision Method

The excision method involves removal of theentire lesion along with some adjacent normal tissue.This procedure is done on small lesions wherecomplete removal would not create significant estheticor functional impairment.

FOREIGN BODY REMOVALS

This is the removal of any foreign body, such as aneedle, metallic restoration, or pieces of elevators,forceps, or even bullets. Such a removal is considereda surgical procedure. It is not always indicated, and isoften left up to the judgment and discretion of thedentist.

SEQUESTRECTOMY

Sequestrectomy procedure involves the removalof devitalized portions of the bone that have separatedfrom the adjacent bone. Often the devitalized portionof bone will work its way partially through the tissueand be sharp and rough.

ALVEOLAR OSTEITIS

After the extraction of a tooth from its alveolus,healing begins immediately when blood oozes into thealveolus and forms a clot. The clot is later replaced byscar tissue and ultimately bone as healing progresses.The blood clot also protects the alveolus from food, air,and fluids. If the blood clot does not form or dislodgesfrom the tooth socket, a painful condition calledalveolar osteitis (also known as a dry socket) mayoccur from 2 to 4 days after the removal of a tooth.With the clot missing, healthy granulation is absentand the tissue within the socket appears grayish incolor and often presents a foul odor. The patient isusually in severe and persistent pain because of theexposed bone in the open socket. In DentalTechnician, Volume 1, chapter 6, we describeemergency treatment for this condition.

PERICORONITIS

The procedure for pericoronitis involves thetreatment of the gingival tissue surrounding a partiallyerupted or malposed tooth, that develops painful,localized inflammation. In Dental Technician,Volume 1, chapter 6, we also describe emergencytreatment for this condition.

SURGICAL INSTRUMENTSTRAUMATIC WOUND REPAIR

Simple and complicated wounds of the facial andor oral soft tissues may be repaired and or sutured inoral surgery.

INCISION AND DRAINAGE

Incision and drainage involves surgicalinter-vention for drainage of an abscess, cyst, orhematoma. A surgical rubber drain can be sutured inthe area to establish drainage.

IMPLANTS

There are several types of surgical implant devicesand associated procedures. An endosseous implant isa device placed in the alveolar bone to support an oralor facial prosthesis. A transosteal or superiostealimplant is a device placed to support an oral or fixedprosthesis. A surgical abutment procedure involvesuncovering the implant and connection of theabutment used in the prosthetic reconstruction ofsingle or multiple teeth.

Many surgical instruments are used in both oralsurgery and periodontic procedures. All surgicalinstruments are made of high-grade steel, eitherstainless or chrome-plated. Each instrument has aparticular purpose and should be handled with extremecare. The instruments with cutting edges must be keptsharp to prevent slippage. Hinged instruments shouldbe lubricated with a milk bath and sterilized in the wideopen position to keep them in good operating conditionand to prevent rusting.

MISCELLANEOUS SURGICAL

INSTRUMENTS

No matter what kind of dental surgery is beingperformed, some miscellaneous instruments willalmost certainly be required. Among these are surgicalsuction, retractors, scalpels, suture needles andmaterials, and surgical scissors. A few otherinstruments, such as mouth props, mouth gags, and asurgical mallet, will also be included with themiscellaneous surgical instruments.

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Surgical Suction Apparatus

Whenever a surgical procedure is performed,sterile instruments are essential. Since it is notpossible to sterilize all parts of the suction apparatusattached to the dental unit, it is necessary to modify itwith a sterile surgical suction apparatus. In some cases,you may use a mobile suction unit that also uses similaritems. These items are composed of the hose, handle,and tips. The hose is used to connect the handle to thesuction apparatus and has a sterile tubing that isavailable in various lengths. The handle has a bulbousportion on one end and a chuck on the other end. Thebulbous portion is slipped into one end of the hose, andthe chuck holds the tips. There are several tipsavailable ranging from #1 to #4. The smaller #2 issuitable for use in a tooth socket. When these parts areproperly joined and the loose end of the tubing isconnected to the suction, they function as a singlesuction unit (fig. 5-2). Your job is to connect the parts,operate the suction, and manipulate the handle and tip.With experience, you should be able to perform thesetasks quickly and efficiently to keep the surgical siteclear for the dentist.

Retractors

There are different kinds of retractors, but thepurpose is the same for each. Retractors are used tohold back objects in the oral cavity.

TISSUE RETRACTORS.—In oral surgery,tissue retractors hold tissue flaps away from thetreatment site to provide better visibility. Someretractors have forklike prongs, as shown in figure 5-3.This allows the handling of the tissue without causingexcessive damage.

TONGUE AND CHEEK RETRACTORS.—These retractors are designed to hold and retract thecheeks, tongue, or a portion of the mucosa during

Figure 5-3.—Tissue retractors.

surgical procedures. The retractors are made of metalor plastic, and may be large, curved, or angled. Acommonly used retractor is the Minnesota retractor,shown in figure 5-4, which is a bent, angled piece ofsteel.

Mouth Props and Gags

Mouth props and gags hold the patient's mouthopen mechanically. The mouth prop, shown in figure5-5, is a solid piece of rubber, whereas the mouth gags

Figure 5-4.—Minnesota tongue and cheek retractor.

Figure 5-2.—Surgical suction handle and tip.

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Figure 5-5.—Mouth prop.

(fig. 5-6) are lock-type forceps with rubber-coveredextensions. The rubber provides protection againstinjury to the enamel of the teeth. The use of mouthprops and gags is by no means limited to surgery. Theyare also commonly used in restorative and pediatricdentistry when patients have difficulty keeping theirmouths open during the procedure.

Surgical Scalpels

Surgical scalpels are composed of handles andblades used to incise or excise soft tissues, and come invarious sizes and shapes. The use of each type dependsupon the type and accessibility of the tissue to be cut.The blades come in presterilized packages and shouldbe discarded after one use. Attach and remove theblades from the handles with hemostatic forceps. Thisprevents accidental cuts and possible infection. Thetwo commonly used surgical scalpel handles are the #3and beaver style. Each handle uses a different kind ofblade and attachment method.

Figure 5-7.—Scalpel Handle #3 and blades.

The #3 handle, shown in figure 5-7, is short andwide; it uses a slotted blade that slides onto the handle.The four blades most often used with this handle arethe #10, #11, #12, and #15. Blades #10 and #15 havesimilar working ends. The greatest difference is thatthe #10 blade is longer. The cutting edge on both of theblades is on the curved part of the blade.

Suture Needles and Materials

Suture needles and materials are packaged insterile packs with the needles and have already beenattached to the suture material. There is a wide varietyof both needles and suture materials.

NEEDLES.—Most suture needles used indentistry are semicircular. They have either smoothsides or cutting sides, and vary greatly as to thediameter of the semicircle, as shown in figure 5-8. Thesmaller sizes are used most often because of the limitedspace in the oral cavity.

MATERIALS.—Dentists use suture materialwith a suture needle to close wounds in and around theoral cavity. Suture materials are usually classified aseither absorbable or nonabsorbable. Almost allsutures used in oral surgery are nonabsorbable. Thesesutures must be removed after the wound heals enoughto hold together. Absorbable sutures are dissolved and

Figure 5-6.—Mouth gags. Figure 5-8.—Suture needles.

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absorbed in the body. Examples of absorbable suturesare the natural (plain and chromic) gut and synthetic

types.

A variety of materials are used to makenonabsorbable sutures. Some of these are silk, cotton,nylon, polyester, and corrosion-resistant steel wire.The most common suture material used in oral surgeryis made of silk.

All of these suture materials are available indifferent diameters. The smaller the number, the largerthe diameter of the suture material. The 3-0 size iscommonly used in periodontal surgery. The mostcommonly used suture material for oral mucosa is the4-0 silk. To suture facial lacerations, the 5-0 suturesize is commonly used.

WOUND CLOSURE.—When assisting withwound closures, grasp the suture needle with theneedle holder approximately one third of the waybetween the eye of the needle and the needle point, andpass it to the dentist. When the needle is inserted intothe tissue, the dentist may require you to hold the tissuefirmly with tissue forceps.

As each suture is tied, the dentist may have you cutthe suture above the knot with surgical scissors, beingcareful not to cut it too short, since this may cause thesuture to come untied.

Surgical Scissors

Scissors are used in dental surgery to cut tissuesand sutures. The scissors used to trim excess orirregular soft tissues have one serrated blade toeliminate slippage. Those with smooth blades arenormally used for cutting sutures or other fabricmaterials. Figure 5-9 illustrates the Dean surgicalscissors. Many types of surgical scissors arecommonly used such as the Kelly curved or sharp,Mayo curved or straight, and the Iris curved or straight.

MISCELLANEOUS SURGERY FORCEPS

With the exception of the rongeur forceps, whichare used to cut bone, most forceps are grasping-type

Figure 5-9.—Dean surgical scissors.

instruments. The forceps that secure patient towelsand drapes, hold suture needles, control hemorrhage,and grasp oral soft tissues are commonly used in mostden ta l su rge r ies . We wi l l cons ide r them amiscellaneous group for our purposes.

Towel-Clamp Forceps

Towel-clamp forceps (fig. 5-10) are used tomaintain surgical towels and drapes in the correctposition during an operation. The working ends mayhave either sharp points or blunt flat tips that overlap inthe closed position.

Needle-Holder Forceps

Needle-holder forceps hold needles duringsuturing procedures. The typical needle holder has twoshort, rather blunt, serrated beaks with a distinctgroove in each beak (fig. 5-11). The grooves providespace for the placement and retention of the needle. Atthe end of the handles, there is a graduated, notched-locking device that lets the dentist secure the sutureneedle in the suturing position as if the needle were anextension of the needle holder.

Figure 5-10.—Small and large towel-clamp forceps.

Figure 5-11.—Needle-holder forceps.

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Hemostatic Forceps

Hemostatic forceps (fig. 5-12) look very much likeneedle-holder forceps. The main difference is that thebeaks of the hemostatic forceps are longer and moreslender. They also have both curved and straightbeaks, and there is a locking device on the handle tokeep the beaks closed. These forceps are used insurgery to control hemorrhage by clamping orconstricting blood vessels. In dental surgery, they aremore commonly used to remove bits of debris, such asbone chips or parts of teeth, from the oral cavity.

Tissue Forceps

Tissue forceps (fig. 5-13) look like cotton forceps,but they have two very small, sharp-pointed extensionsthat form a W-shape when in the closed position.Although the tissue forceps are used in oral surgery tograsp and stabilize loose tissue ends during suturingprocedures, they are mainly used to hold tissue beingexcised.

CUTTING INSTRUMENTS USED INDENTAL SURGERY

When most people hear the word "surgery," thefirst thing they think about is the cutting of the body

Figure 5-12.—Hemostatic forceps.

with scalpels. Scalpels are not the only cuttinginstrument used in surgery, particularly dentalsurgery; for instance, curettes, chisel, rongeur forceps,and bone files are also used in some cutting functions.

Surgical Curettes

While surgical curettes are not strictly cuttinginstruments, they must do some cutting. Curettes aresharp, spoon-shaped instruments used to clean outinfected cavities in bone and remove debris from thetooth sockets. They come in many sizes and in straightor angled shapes. The type used depends on the natureof the socket, curvature of the roots that were in thesocket, and the location of the cavity. The single-ended Molt curettes have large handles. They are thestraight #2 and #4 and the paired, angled #5L and #6R(L for left, and R for right). They are shown in figure5-14. Other curettes in dental surgery may be double-ended and have slender handles.

Surgical Chisels

Surgical chisels may also be classified as cuttinginstruments. Like surgical burs, chisels are used toremove bone and to split teeth. Because their cutting

Figure 5-13.—Tissue forceps. Figsure 5-14.—Single-ended surgical curettes.

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edges are easily dulled, you must sharpen them aftereach use. Surgical chisels are much larger than enamelchisels used in restorative dentistry. The surgicalmallet (fig. 5-15) is used along with a selected chisel tosplit teeth or reduce alveolar bone.

Rongeur Forceps

Rongeur forceps (fig. 5-16) are used to trimp r o j e c t i n g , u n e v e n , o r o v e r h a n g i n g b o n e(alveolectomy), usually after multiple extractions andbefore tissue suturing. It has a steel spring spreader,which opens the beaks when pressure is released fromthe handles.

Bone File

Although most of the bony projections areremoved with the rongeur forceps, some rough edgesusually remain. The bone file (fig. 5-17) may be usedto further shape and smooth the alveolar bone. Theyare double-ended instruments, with both large andsmall working ends.

Figure 5-15.—Surgical chisels and mallet.

Figure 5-16.—Rongeur forceps.

Figure 5-17.—Bone file.

SURGICAL ELEVATORS

Three types of surgical elevators are used in oralsurgery: the periosteal, root, and malar. Root picks areclassified as root elevators and will also be discussed.

Periosteal Elevators

During surgery the dentist often needs to separate abone or tooth from the fibrous membrane, called theperiosteum that covers it. This is done with a periostealelevator. The dentist may also use it to gain access toretained roots and surrounding bone. Two periostealelevators are the Molt #9 and Seldin #23 shown infigure 5-18. The Molt #9 is used exclusively as aperiosteal elevator. The Seldin #23, because of its wideworking ends, is also used as a retractor.

Root Elevators

Root elevators come in many sizes and shapes. Atleast one (and sometimes more) is used in every toothextraction. Which elevator or elevators that are usedwill depend upon the desire of the dentist. A rootelevator has three functions:

To loosen the teeth in their sockets.

To remove parts of teeth (broken root tips orretained roots).

To remove a complete tooth.

Figure 5-18.—Periosteal elevators.

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In the last case, the tooth is usual ly anunderdeveloped third molar. The elevators areactually levers. The fu lcrum (support point) for theelevator is usually the bone supporting the tooth.

STRAIGHT ROOT ELEVATORS.—Theelevators composing the straight working end groupare the #301 and the #34S (figs. 5-19 and 5-20). The

Figure 5-19.—Root elevator #301.

Figure 5-20.—Root elevator #34S.

working ends are in line with the handle and have aconcave surface. The #301 has the smallest workingend and is used when roots are deeply seated. The#34S has the largest end and is commonly used foranterior roots. The #92, shown in figure 5-21, also hasa straight working end; however, it is serrated and theshanks are angled rather than straight as in the #301and #34S.

SPADE/WEDGE-TYPE ROOT ELEVA-TORS.—Another style of elevator has spade orwedge-type working ends. The Stout #11 (fig. 5-22)and the Cogswell A (fig. 5-23) are examples of thisstyle. The Cogswell B, also shown in figure 5-23, is apick-shaped root elevator that has a working endshaped similar to a rounded toothpick tip.

ANGLED-TYPE ROOT ELEVATORS.—Inseveral sets of elevators, the handles are in line with theshank, but the working ends are set at an angle. The

Figure 5-21.—Serrated root elevator #92.

Figure 5-22.—Stout #11 root elevator.

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Figure 5-23.—Cogswell A and B root elevators.

Miller #73 and #74 elevators, shown in figure 5-24,have curved, thin working ends with smooth, roundedtips. These elevators are designed to elevate a tooth orlarge root fragment. The Seldins #1L and #1R, shownin figure 5-25, have sharp-tipped working ends with anabrupt 90-degree angle. The Seldins, sometimereferred to as East- West elevators, are designed for useon molar roots. The Cryer #25 and #26 are similar tothe #1L and #1R Seldins; however, the working endsare angled at angles greater than 90 degrees (fig. 5-26).

APICAL ROOT TIP PICK ELEVATORS—This group of elevators are used to remove fracturedroot tips lodged deep in the root socket. Theseelevators are often called root picks. Elevators thatmake up this group are the #5 and #6 West, and the #9apical, #9L, and #9R. The working ends on theseelevators are very thin, sharply pointed, and small. The

Figure 5-24.—Miller root elevators.

Figure 5-25.—East-West (Seldin) root elevators.

Figure 5-26.—Cryer root elevators.

#5 and #6 West, shown in figure 5-27, have muchshorter shanks and are designed to remove extremelysmall apical fragments. The #9L and #9R are set at leftand right angles to the handles (fig. 5-28). The handlesare also small in diameter but longer than those onother elevators discussed earlier.

Malar Elevator

The facial bone that forms the cheek is called thezygoma or malar bone. An injury to this bone oftencauses a depressed fracture. If this occurs, the dentistwill use a malar elevator to raise the bone to its normalposition.

Figure 5-27.—Apical root tip picks (#5 and #6 west).

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Figure 5-28.—Apical root tip picks (#9L and #9R).

TOOTH EXTRACTION FORCEPS

There are several types of tooth extracting forceps.Except for those made for some specific operation,they generally have the same features: beaks, a neck,and handles, as shown in figure 5-29. The beaks oftooth extracting forceps are designed to grasp the toothwith maximum contact on the facial-lingual surface ofthe root(s) just below the cervix. The inner surface ofeach of the two beaks is concave and the outer surfaceis convex.

Figure 5-29.—Parts of forceps.

Tooth extracting forceps are designed for use inspecific areas of the mouth. The beak is always shapedto conform snugly to the contour of the tooth. Forexample, both beaks of maxillary forceps are usuallyangled away from the curvature of the handles. Thesevarying angles make it easier to reach various parts ofthe arch. The beaks of mandibular forceps are usuallyat a much sharper angle and in the same direction as thecurvature of the handles. This makes it easier to reachdifferent parts of the lower arch.

Another way of identifying the general area of themouth in which tooth extracting forceps should beused is by its neck. The neck is shaped so that the beakcan be placed on the tooth and still be parallel with thelong axis of the tooth. The handles are shaped so that amaximum amount of force can be applied to the beaks,while the handles are still in a comfortable position forthe oral surgeon. The beaks are also shaped so that aforce on the handles tends to force the tooth out of itssocket.

The overall shape of the forceps, from the beak tothe handle, can usually provide quick identification ofthe arch for which it's designed. The S, I, and Z shapedforceps are used on the maxillary arch (fig. 5-30).Forceps which are C and L shaped are used on themandibular arch (fig. 5-31).

Figure 5-30.—Maxillary shaped extraction forceps.

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Figure 5-31.—Mandibular shaped extraction forceps.

Dentists and oral surgeons will select forceps thatare the most comfortable and provide the best results.So you can better assist during oral surgeryprocedures, you need to know where particular forcepsare used. We will cover some of the more commontooth extracting forceps and where they are used in themouth.

Maxillary, Incisors, Cuspids, andBicuspids

Some of the more commonly used extractionforceps designed for use in maxillary, incisor, cuspid,and bicuspid areas of the mouth include the #1, #65,#150, and #286.

FORCEPS #1.—Forceps #1 are used to removemaxillary incisors and cuspids. The beaks (graspingparts) are in line with the handle (fig. 5-32). Because ofthe straight line design, a dentist can exert a lot ofleverage.

FORCEPS #65.—Forceps #65 are used onoverlapping maxillary incisors and root tips. Thehandles of the #65 forceps are straight and the beaksare offset (fig. 5-33). When the forceps are closed,they resemble a bayonet. The beaks are short, verynarrow, and slender.

Figure 5-32.—Forceps #1.


FORCEPS #150. —The Forceps #150 aresometimes referred to as maxillary universal forceps.Even though the #150 forceps can be used in anyregion of the maxillary arch, they are specificallydesigned to remove maxillary incisors, cuspids,bicuspids, and residual roots. The beaks are set at anangle to the handles, which makes them accessible toany part of the maxillary arch (fig. 5-34). When thehandles are closed, the beaks are noticeably close

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together at the tips and curve opposite each other toresemble "parentheses."

FORCEPS #286.—Forceps #286 are similar toforceps #65. The biggest differences are that the #286beaks are wider, and there is a wider space between thebeaks nearest the handles when they are closed. Thesecharacteristics make the #286 (fig. 5-35) a little moresuitable than the #65 for removing maxillarybicuspids. The #286 also is used to remove maxillaryincisors and residual roots.


Maxillary Molars

Extraction forceps for maxillary first and secondmolars are designed as left and right forceps becausethese teeth are trifurcated. Some of the commonlyused forceps for these teeth are the #53L, #53R, #88L,and #88R. Forceps designed for third molars includethe #210H and #210S.

FORCEPS #53L AND #53R.—Forceps #53Land #53R are used to extract maxillary first and secondmolars. The letters "L" and "R" indicate that theforceps are used on the left and right sides of themaxillary arch. They have straight handles with offsetbayonet-type beaks (fig. 5-36). The design lets thedentist grasp the tooth securely for rocking andelevating movements.

root portion of a tooth so the dentist can rock the toothfrom its socket. The #88L and #88R forceps (fig. 5-37)operate on a wedging principle. They are insertedbetween the tooth and roots and the surrounding bone.

FORCEPS #88L AND #88R.—Forceps #88Land #88R are often called cowhorns. Like the #53Land #53R, they are used on the maxillary first andsecond molars. They differ slightly from the #53L and#53R in the way they remove a tooth. The primary useof the #53L and #53R forceps is to grasp the crown and

The wedging action of these straight handled forcepslifts the tooth from its socket.

Figure 5-36.—Forceps #53L and #53R.

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Mandibular Incisors, Cuspids, and Bicuspids

Figure 5-37.—Forceps #88L and #88R.

FORCEPS #210H AND #210S.—Forceps#210H and #210S are used to remove maxillary thirdmolars (fig. 5-38). The #210H has short beaks andsmooth rounded tips and a wide concave inner surface.The end of the left handle is noticeably curled to form afinger rest. The #210H is particularly effective ingrasping the generally underdeveloped maxillary thirdmolar crowns. The #210S forceps have a slightly widerbeak than the #210H, and there isn’t a finger rest curl. Itis also used to extract maxillary third molars.

Two commonly used extraction forceps for themandibular anteriors and bicuspids are the #151 and#203.

FORCEPS #151. —Forceps #151 are usedprimarily to extract mandibular anteriors, bicuspids,and roots and are often known as the mandibularuniversal forceps. These forceps are similar to the#150 forceps except the beaks are set at an angleopposite to the slightly curved handles (fig. 5-39).

FORCEPS #203.—Forceps #203 are used onmandibular anterior, bicuspids, and roots. Theseforceps are like the #101 (mentioned later), exceptthe beaks are more sharply angled from the handles.Like the #101 handles, the #203 handles are straight(fig. 5-40).


Figure 5-38.—Forceps #210H and #210S. Figure 5-40.—Forceps #203.

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Mandibular Molars

There are several popular extraction forceps forthe mandibular molars, including the #15, #16, #17,#217, and #222.

FORCEPS #15.—Forceps #15 are used to removemandibular first and second molars. The beaks haveconcave inner surfaces with pointed projection on thetips. These forceps work well in grasping the crownwith the two projecting tips extending to thebifurcation between the two roots on mandibular thirdmolars. The left handle on the #15 has a finger rest.

FORCEPS #16.—Forceps #16 are used to removemandibular molars. The #16 forceps are nicknamedmandibular cowhorns when they are open. The lefthandle on the #16 has a finger rest.

FORCEPS #17.—Forceps #17, like the #15 and#16 forceps, are used on lower first and second molars.The beaks of the #17 forceps are similar to the beaks ofthe #15 forceps; however, the handle of the #17 isstraight.

FORCEPS #217.—Forceps #217 are used toremove mandibular second and third molars (fig.5-41). The beaks have inner concave surfaces andpointed projections much like those of the #15 forceps.The handles have a slight curvature and resemble thoseof the #151 forceps.

FORCEPS #222.—Forceps #222 are used onmandibular third molars. The beaks on the #222forceps are rounded with concave inner surfaces, andangle sharply from the handle (fig. 5-42).



HAWKBILL-TYPE FORCEPS.—There arethree hawkbill-type forceps: the Mead #MD3, the#13, and the #22 (fig. 5-43). The Mead #3 forceps areused on mandibular anteriors and bicuspids, the #13forceps are used on mandibular first, secondbicuspids, and the #22 forceps on mandibular first,second, and third molars. The beaks are perpendicularto the working action of the handles. This designgives the dentist a great deal of leverage withminimum effort. The major difference between theseforceps is the width of the beaks, because they areused to remove different teeth.

FORCEPS #101.—Forceps #101 are used toremove both maxillary and mandibular cuspids,bicuspids, and any remaining roots (fig. 5-44).

P E D I A T R I C F O R C E P S # 1 5 0 S A N D#151S.—The pediatric forceps #150S is used toremove maxillary deciduous teeth and is a scaled downversion of the #150. The #151S, a smaller version ofthe 151, is used to remove mandibular deciduous teeth.Both forceps are shown in figure 5-45.

PASSING AND RECEIVING OF SURGICALINSTRUMENTS

Instrument exchange between the dentist andassistant takes place in the transfer zone near the

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Figure 5-43.—Hawkbill-type forceps used on mandibular teeth.


Figure 5-45.—Pediatric Forceps #150S and 151S.

patient's chin. As an assistant, you must anticipate thedentist's needs and be ready when signaled by thedentist to pass the next instrument and receive the usedone in a smooth motion.

Double-handled instruments, such as scissors,hemostats, and forceps, along with single-endedinstruments with bulb-type handles, such aselevators, are transferred somewhat differently asdiscussed in previous chapters. As figures 5-46 and5-47 illustrate, when passing these types ofinstruments, grasp the working end and place thehandle into the palm of the dentist's hand. Theworking end of the passed instrument should bepointed toward the correct arch. When the dentistfinishes with the instrument, you will receive theinstrument by grasping the working end.

SURGICAL AIR DRILL

Many different makes and models of surgical airdrills are used in oral surgery. A common surgical airdrill used in the Navy is shown in figure 5-48. It is ahigh-speed hand piece used in oral surgery proceduresto remove bone and section teeth. The drill enables thedentist to accomplish these procedures quickly andreduces the trauma to oral tissues. It operates by a handcontrol lever while other makes and models operate bya foot pedal.

Bur guards (fig. 5-49) are used with the air drill.Surgical burs are then inserted into the drill after thebur guard is in place. Bur guards are available in threelengths: medium, long, and extra long. They aredesigned to protect the dentist and the patient from thelong shaft of the burs. Selection of a bur guard isdirectly dependent on the length of the bur to be used.

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Figure 5-46.—Transfer of surgical forceps.

Surgical burs (fig. 5-50) are designed specificallyfor surgical procedures with extra-long shanks. Theyare made to fit both straight and contra-anglehandpieces.

Figure 5-47.—Transfer of a surgical elevator.

The attachments required to assemble andoperate the surgical air drill consist of a powersource (compressed dry nitrogen tank), a pressureregulator, and a pressure/exhaust hose. Consult the

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Figure 5-48.—Surgical air drill.

Figure 5-49.—Bur guards used with the surgical air drill.

Figure 5-50.—Surgical burs.

manufacturer's operating instructions for use andmaintenance of the surgical air drill.

ASSISTING IN DENTAL SURGERY

Before the surgery, you should discuss theessentials for each dental surgery procedure with thedentist. Advance preparation is essential to establishand maintain asepsis during the surgical procedure.With such preparation, you can be sure to have thenecessary instruments, equipment, and materials readyfor each patient.

The types of assistants that are commonly usedduring most outpatient dental surgery in clinics andaboard ships are the circulating and the scrub assistant.

CIRCULATING ASSISTANT

The circulating assistant plays an important roleduring the dental surgery procedures and is responsiblefor many tasks which include, but are not limited to:

Taking pulse and blood pressure.

Receiving and seating the patient.

Preparing the surgical room.

Maintaining the chain of asepsis.

Positioning the dental chair.

When the dentist is ready to begin surgery, thecirculating assistant will bring the surgery tray andplace it on the Mayo stand (adjustable tray stand). Toavoid contaminating the contents of the pack, touchonly the outside edges of the wrappers.

After the extraction tray is opened, the circulatingassistant will stand by to assist the dentist and the scrubassistant. When the procedure has been completed andthe patient has been dismissed, disinfect and clean theroom for the next patient.

SCRUB ASSISTANT

The scrub assistant will assist the dentist during thesurgery procedure. Transferring of instruments, andkeeping the surgical site clean and clear of debris andblood for the dentist to operate efficiently are the majorduties of the scrub assistant.

Once the surgical procedure is completed, thedentist may use sutures to close the surgical wound. Ifthe sutures have been placed, the dentist may want apressure pack (dressing) over the extraction site to stopthe flow of bleeding. Proper post-surgical instructionswill also be given to the patient before dismissing.

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PRESURGICAL PROCEDURES

During the presurgical procedures, you willreceive the patient, and prepare the surgical room. Tomaintain asepsis in the surgical room, you may need totake a number of special measures. The members of thesurgical team may wear sterile, disposable gowns overtheir regular working uniforms, surgical caps, masks,and hoods (if bearded). Scrub the patient's face anddrape the patient with sterile drapes. The dentist andthe scrub assistant (or other team member) mustperform a surgical scrub and put on sterile surgicalgloves and gowns before any oral surgery proceduresbegin.

RECEIVING THE PATIENT

As the circulating assistant, you will receive thepatient once the surgical suite is prepared. Surgerypatients may be nervous or fearful; take special carewhen receiving them.

Seat the patient and make them as comfortable aspossible. Direct the patient to loosen any tight clothing,remove eyeglasses and any removable dentures. If thepatient has dentures, place them in a container of waterand put their eyeglasses in a safe place.

Before starting any surgical procedure, thecirculating assistant will take the patient's pulse andblood pressure. The patient's vital signs will berecorded on the EZ603.

The dentist will usually stand when performingoral surgery. Position the dental chair so that thepatient's head is at the level of the dentist's elbow. If thesurgery is to be performed on the maxillary arch,position the chair so that the patient's alatragus line is ata 35° angle to the floor. For surgery on the mandibulararch, position the chair so that the patient's alatragusline is parallel with the floor.

PREPARING THE SURGICALROOM

After the patient has been seated, the circulatingassistant prepares the surgical room for the surgicalprocedure. Arrange the instrument stand (Mayo stand)with the following instruments and materials:

Patient scrub setup.

Surgical drape pack.

Two packs of disposable, sterile gloves.

A simple or complex surgical extraction pack,plus any additional instruments or materialsrequested by the dentist. Place the pack(s) on theMayo stand. Position the stand to the rear of thedental chair so that the instruments are withineasy reach of the dentist and the scrub assistant.

Anesthesia pack (if one is not included in theextraction pack).

NOTE: Do not open any of the packs at this time.

Once the instruments and materials have been setout, the circulating assistant gets ready to perform thepatient scrubbing procedures.

PATIENT SCRUBBING PROCEDURES

The circulating assistant scrubs the patient's face.During the scrub procedure, take special care to seethat patients with facial hair, makeup, sores, or skininfections are thoroughly cleansed. The scrubbingprocedures are as follows:

NOTE: The circulating assistant must wear gloveswhen performing the following steps.

Place a hand towel on the patient's chest to keepthe patient's clothes from being stained. Tuck thetop of the towel inside the patient's collar. (Useanother hand towel if you need more coverage.)

Saturate two 4 x 4 sterile gauze sponges with thesurgical soap solution.

Use both sponges to scrub the patient's cheeks,nose, and chin. Work up a good foaming latherand be sure to scrub the area beneath the chin.After 1 minute, discard the two sponges, thenwith two new sponges, continue the scrub. Theentire process should take approximately 2minutes.

After the scrubbing procedure is completed, blotthe excess lather with a sterile towel.

SURGICAL TEAM SCRUBBING,GLOVING, AND DRAPING

While the circulating assistant finishes preparingthe patient, the dentist and scrub assistant will preparefor surgery. The circulating assistant will help theother team members during the following procedures.

Scrubbing

The dentist and the scrub assistant will perform thesame procedures, which requires an antimicrobial

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from polish, and the cuticles are trimmed. Then,

surgical product, a nail cleaner, and a sterile handbrush or sponge. These materials are available in thescrub area. Before scrubbing, remove all rings,watches, or other jewelry from your hands and arms.Ensure that your fingernails are short, smooth, free

complete the following procedures:

1.

2.

3.

4.

Wet your hands and arms with water. Put a smallamount of antimicrobial surgical product in thepalm of your hand and spread the solution overyour hands and arms. Work the solution into agood lather.

Clean your nails and cuticles with a nail cleanerunder running water. When you are through,discard the nail cleaner.

Rinse your hands and arms under running water.

Wet the brush or sponge and place a smallamount of the antimicrobial solution on thebristles. Scrub each hand and arm in thefollowing manner:

Place your fingers together and scrub acrossthe tips for 30 strokes.

Starting with your thumb, scrub each fingeron all surfaces. Use 20 strokes for each finger,and make sure that the webbed areas betweenthe fingers are scrubbed.

After you have scrubbed each finger, scrubyour palm. Use a circular motion and scrub for20 strokes.

Scrub from your wrist to 2 inches above yourelbow. Brush in one direction only (awayfrom the wrist) and scrub for 20 strokes.

WITHOUT RINSING, wash your otherhand and arm in the same manner. Thendiscard the hand brush or sponge.

5. Rinse both hands and arms. Hold your handshigher than your elbows and allow the water toflow from your fingertips to your elbows.NEVER move your hands back and forththrough the water. Allow the water to drip fromyour elbows for a few seconds before leavingthe scrub area. When leaving the scrub area,hold your hands close together and away fromyour body. DO NOT touch anything.

6. While the scrub assistant and the dentist scrub,the circulating assistant will open the surgicaldrape pack, being careful to touch only the

outside edges of the pack. When the scrubassistant enters the operating room, use a steriletowel from the pack to dry the hands and arms,being careful not to drip on the sterile field.

7. On one half of the towel, use a blotting action todry one hand and arm, from the fingers to abovethe elbow. Dry your other hand and arm in thesame manner with the other half of the towel.NOTE: When drying, bend at the wrist and holdyour hands and arms away from your body. Thiswill keep the sterile towel from coming incontact with your unsterile scrub suit.

8. When this procedure is complete, pass the towelto the circulating assistant.

NOTE: The above scrubbing routine is normallyperformed for the first case in the morning and againafter lunch. Otherwise, an abbreviated scrubprocedure, consisting of a 2-minute washing pro-cedure of your hands and arms with antimicrobialsurgical product should be performed.

Gloving

After the scrubbing procedure is completed, thesurgical team will don sterile surgical gloves. Glovingprocedures are the same for the dentist and the scrubassistant.

The circulating assistant will open the packages ofdisposable sterile gloves, touching only the outsideedges of the packages. The procedures for putting onthe gloves are as follows:

1 .

2 .

3 .

Without touching the gloves, fold back thetissue paper covering. The cuff of each glove isfolded so that the inside of the cuff is partiallyexposed. NOTE: Touch only the inside portionof the glove with your bare hand.

Grasp the first glove at the cuff fold (fig. 5-51).Gently pull the glove onto your free hand andanchor the cuff over your thumb (fig. 5-52).

Slip the fingers of your gloved hand under thefolded cuff of the second glove. Keeping yourfingers under the folded cuff, begin to work thesecond glove onto your bare hand (fig. 5-53). Dothis gently so that the cuff remains folded. Workthe glove up, and over your hand and wrist, andonto your arm (fig. 5-54). As you do this,gradually unfold the cuff so that its inner side isnow against your skin. Remember that youcannot touch this exposed inner side with yourgloved hand. Finally, grasp the outside of the

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Figure 5-51.—Grasping the first glove at the cuff fold.

Figure 5-52.—Anchoring the cuff over the thumb.

Figure 5-53.—Working the second glove onto your bare hand.

glove and pull it completely on. One hand isnow fully gloved.

4. Slip the fingers of your gloved hand under thefolded cuff of the first glove (fig. 5-55). Workthe cuff over your wrist and onto your arm.Gradually unfold the cuff so that its inner side is

Figure 5-54.—Working the glove up over the hand and wristand onto the arm.

Figure 5-55.—Slipping gloved fingers under the cuff of thefirst glove.

now against your skin. Then grasp the outside ofthe glove and pull it completely on.

Draping

Both the dentist and the scrub assistant will drapein the following manner:

1. Remove a sterile hand towel from the drapepack. Hold it away from your body and allow itto unfold. Make sure that the towel does notcome into contact with your scrub suit or anyunsterile item.

2. Raise the towel to shoulder height, holding it sothat a small cuff is formed at the top of the towel.

3. The circulating assistant will grasp one of thetop edges at the cuff and fasten it to the shoulderof the scrub suit with a towel clip. Then thecirculating assistant will fasten the other top

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edge in the same manner. After the dentist andscrub assistant are draped, the circulatingassistant will drape the patient.

Draping The Patient

The drapes remaining in the drape pack are for thepatient. The drape pack consists of a body drape, headdrape, and four sterile towel clamps. Additional drapesmay be used, depending on the preference of thedentist. The scrub assistant will drape the patient in thefollowing manner:

1. Grasp the corners of the body drape. Lift it upand away from the pack, allowing it to unfold.Hold the drape so that a small cuff is formedacross the top. Be sure that the drape does notcome into contact with unsterile items. Do notshake the drape.

2. Carry the drape to the patient and place the topedge directly under the patient's chin and overthe shoulders. The remainder of the drapeshould cover the patient's chest and upperthighs.

3. Grasp the corners of the head drape and removefrom the pack in the same manner as the bodydrape. The cuffed portion of the inner drapeshould be up and folded away from you.

4. Place the top of the drape over the headrest ofthe dental chair (fig. 5-56).

Figure 5-56.—Top of the head drape placed over the headrest.

5. Grasp the inner drape by the corners and drawthe left side of the drape over the patient's lefteye and the bridge of the nose. Then draw theright side of the drape over the patient's right eyeand the bridge of the nose. Using a sterile towelclamp, fasten the two sides of the head drapetogether.

6. Using a sterile towel clamp, fasten the left sideof the head drape to the left side of the bodydrape; then do the same thing on the right side.The patient is now completely draped and readyfor the surgical procedure.

SURGICAL PROCEDURES

Surgical procedures cover the duties of thecirculating assistant and the scrub assistant duringthe procedure. Because of the importance ofmaintaining asepsis in the operating room, this sectionwill begin with a discussion of certain rules of theaseptic technique.

RULES OF THE ASEPTIC TECHNIQUE

These rules are designed to help you avoidcontaminating instruments and materials during oralsurgery. By following them closely, you will greatlyreduce the possibi l i ty of introducing cross-contamination into the oral cavity during the surgicalprocedure.

1. An article is either sterile or unsterile. If there isany doubt, consider the article unsterile anddiscard it immediately.

2. Do not open a sterile pack or container until thearticle(s) is/are required.

3. If you are the circulating assistant, touch onlythe outside edges of the wrapper when openinga sterile pack. Take care when unfolding thewrapper so that the inside does not brushagainst your clothing. If you are the scrubassistant, never touch the outside of a pack.

4. Wear sterile gloves and change gloves if theybecome punched or torn. Make sure youdiscard the contaminated gloves.

5. Remove sterile articles from a pack or acontainer by lifting them straight up and out.Never drag an article over the edge of a pack ora container.

6. Once an article is removed from a sterile packor a container, do not place it back in the pack.

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7.

8.

9.

10.

11.

12.

13.

14.

15.

Place sterile articles on a dry, sterile surface.Moisture will contaminate the articles.

Only the top portion of a draped instrumentstand should be considered sterile. Sterilegloves must be used in this area. Any portion ofthe wrap hanging over the edge of the stand isconsidered unsterile.

If an instrument becomes contaminated,discard it immediately.

If a delay occurs in the procedure, the scrubassistant should cover all unwrapped packswith sterile drapes.

All sterile articles set out for a procedure mustbe cleaned and sterilized or disposed of afterthe procedure is completed. This pertains toarticles that were not used.

Never reach behind another draped member ofthe surgical team.

Always keep your hands above your waist.

Always face the draped patient and the othermembers of the surgical team. If it becomesnecessary to pass another draped member ofthe team, pass back to back.

Always pass an unsterile object in theoperating room with your back toward theobject. Unsterile objects include chairs, desks,cabinets, and similar items.

INSTRUMENT SETUP AND MATERIALS

It is critical that you establish and maintain a sterilefield when preparing for a surgical procedure. A scrubassistant must have on sterile gloves when a sterilesurgical tray is opened for a surgical procedure. Thecorners of the wraps are carefully unfolded andallowed to drape over the surface where the tray ispositioned to provided a sterile field. The instrumentsand materials should be arranged in the sequence inwhich they are most commonly used during theprocedure. This expedites the exchange of instrumentsbetween the scrub assistant and the dentist, and avoidssearching the tray for an out-of-place instrument.Once instruments are used, they should be returned totheir proper location whenever possible. Both thescrub and circulating assistants should know all thesurgery instruments to be used by name, number,purpose, and sequence of use.

As part of the preparation, the scrub assistant mustassemble several items on the tray setup, such as

Figure 5-57 illustrates a tray setup for a complex orimpacted surgical extraction. Please note that all theinstruments shown in figure 5-57 may not be in thesame setup that you may use at your command. Thesurgical tray setup should be kept covered with a steriletowel until the procedure begins.

POST-OPERATIVE PROCEDURES

Some of the more common post-operativeprocedures that the dentist may direct you to performinclude control of bleeding, post-surgical instructions,and suture removal.

CONTROL OF BLEEDING

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After an extraction, place a moistened pressurepack made of folded, sterile gauze squares over thesocket (fig. 5-58). It is important that this pack stays inplace to control bleeding and encourage blood clotformation. Instruct the patient to keep the pack in placefor at least 30 minutes to an hour. Warn the patient thatremoving the compress too soon will disturb blood clotformation, and may increase the tendency ofhemorrhage and delay healing. Give the patient extragauze to place an additional pressure pack ifhemorrhage has not stopped after the original pack isremoved. Advise the patient to limit activity and avoidstrenuous work or exercise for a few days after surgeryto avoid hemorrhage at the surgical site.

POST-SURGICAL INSTRUCTIONS

Post-surgical instructions to patients are importantguidelines that they should follow to preventcomplications and unnecessary discomfort. In manyinstances, the dental assistant may be responsible forgiving the post-surgical instructions to the patient. It isadvisable to discuss these instructions with the patientafter the surgery to prevent confusion. If a patient issedated, verbal instructions must be given to thepatient before the sedation and to the patient's escort.

In either case, the patient should be given a printedcopy of the instructions to review after leaving thedental cl inic. Pat ients tend to forget verbalinstructions, especially when they are given right after

anesthetic syringes, scalpel and blade, irrigationsyringe and tip (or bulb syringe if used), surgicalsuction tip, and handle with tubing. First, thecirculating assistant fills the metal cup with sterilesaline. After that the scrub assistant fills the irrigationsyringe from the cup.

Figure 5-57.—Tray setup for a complex or impacted surgical extraction.

surgery. Verbal instructions are given only toemphasize the important written guidelines.

to keep the gauze pack in place over the surgical sitewith light pressure until the hemorrhage stops or thegauze becomes saturated. Following surgery, manypatients are so relieved the surgery is completed thatthey will try to talk and ask numerous questions. Thisshould be firmly discouraged by explaining to thepatient that healing depends on establishing good clotsand steady light pressure. The gauze pack need not bereplaced if bleeding has ceased. A slight ooze can beexpected at times and could continue for a few hours.

Stress to the patient that home care followingdental surgery is important and recovery could bedelayed if this is neglected. Inform the patient thatsome swelling, stiffness, and discomfort are to beexpected. If these reactions are greater than expected,inform the patient to call or return to the dental clinicfor care.

The expected effect of anesthesia, both local and Advise patient to limit activities and avoidconscious sedation agents, if applicable, should be strenuous work or exercise for a few days after surgery.explained to the patient and escort. Inform the patient Caution the patient to keep the head elevated with

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pillows when resting or sleeping during the first 24hours since lowering the head increases blood pressureand can promote continued bleeding.

Figure 5-58.—Placing a pressure pack.

Instruct the patient not to smoke or use a straw forat least 24 hours. Frequent spitting, sucking on thewound, and using mouthwashes should be avoidedduring this time to secure an adequate blood clot.

Inform the patient to take the prescribedmedications for pain, and the antibiotics to preventinfection (if prescribed). It is best if the patient takesthe first dose of pain medication after the removal ofthe initial gauze pack. This allows the pain medicationto enter the blood stream before the effects of the localanesthesia wears off.

swelling.

Instruct oral surgery patients to place an ice bag orchemical cold pack- on the external area of thetreatment site for the first 24 hours only, to minimizeswelling. Apply the ice for at least 30 minutes on andthen 30 minutes off after the surgery. Any amount oftime less than this will not permit the cold to penetratethe tissues adequately. Cold is effective in decreasingedema by constricting the blood vessels. Heat may beplaced on the jaw after the first 24 hours to minimize

You should recommend a soft diet and sipping ofwater and fruit juices for a few days following dentalsurgery. Make sure the patient has an appointment toreturn for a post-surgical check in 3 to 5 days.

You should always remain with your surgicalpatients until they recover enough to be dismissed.Dismiss your patients as cordially as you receivedthem. Closely observe the patients as they leave tomake sure that they are steady and show no signs ofdistress. If patients exhibit any signs of dizziness,detain them until the dentist can evaluate theircondition.

SUTURE REMOVAL

Sutures can be removed 3 to 7 days followingsurgery, depending on the material and procedure. Forexample, nylon or silk sutures are removed from 3 to 5days after surgery if adequate healing has taken place.After the extraction site is examined by the dentist,suture removal can be delegated to the assistant.

Irrigate or swab the suture site with an antisepticsolution to remove any debris. Locate and account forall the sutures placed during the surgical treatment.Use a hemostat or cotton forceps to gently lift thesuture away from the tissue to expose the attachment ofthe knot. With the scissors in the other hand, slip oneblade of the scissors under the suture and one bladeover the suture. Cut the suture material as close to thetissue as possible so that a minimum of material ispulled through the tissue. Grasp the knot and gentlyslide the suture out of the tissue. Take care not to pullthe knot through the tissue, since this causesunnecessary discomfort to the patient. Continue liftingand snipping the suture material until all sutures areremoved. Count and compare the number of suturesremoved with the number placed as indicated in thepatient's record. Irrigate the surgical area withantiseptic solution if there is any bleeding.

COMMON POST-SURGICALCOMPLICATIONS

Just as with any surgical procedure, there can becomplicat ions. In oral surgery, the commonpost-surgical complications are alveolar osteitis,swelling, and bleeding. These complications havebeen discussed in Dental Technician, Volume 1,chapter 6, "Emergency Treatment of Oral Diseasesand Injuries," and under the Post-Surgical Instructionssection in this chapter.

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CHAPTER 6

PERIODONTIC ASSISTANCE

PERIODONTICS

Periodontics is that branch of dentistry pertainingto the diagnosis and treatment of the supporting andsurrounding tissues of the teeth and their substitutes. Italso includes the implantation or transplantation ofteeth and their substitutes. The goal of modernperiodontal therapy is to preserve and maintainperiodontal health, aesthetics, and function of naturaldentition and implanted tooth replacements.

The supportive structures, collectively termed theperiodontium, consist of the gingiva, periodontalligaments, and alveolar bone. Diseases that damage theperiodontium are called periodontal diseases.

To prepare for this chapter, review chapters 5, 6,and 8 of Dental Technician, Volume 1, NAVEDTRA12572, and chapter 3 of this manual. In chapter 5,"Oral Pathology," we discuss pathology of theperiodontium. In chapter 6, "Emergency Treatment ofOral Diseases and Injuries," we discuss diseases of theperiodontal tissues. In chapter 8, "Nutrition and Diet,"we discuss preventive dentistry and nutrition. Inchapter 3, "Preventive Dentistry," we discuss oralhygiene and supragingival scaling. In this chapter, wewil l cover the funct ions and indicat ions ofperiodontics.

FUNCTIONS

is diagnosed as systemic (affecting the body as awhole), the patient should be referred to the medicalfacility for diagnosis and treatment of the medicalcondition.

The treatment of periodontal diseases mayencompass both the dental and medical professions.When the cause of a patient's periodontal disturbance

The dental treatment of a periodontal patient mayrequire coordinated treatment from other specialtyareas. Often, patients needing periodontal treatmentare referred from specialty areas where they wereseeking treatment for other related dental problems.For example, the patient may need a prostheticappliance to replace some missing teeth. However, thepatient 's periodontal condit ion may requireperiodontal treatment before the appliance can be

made. In evaluating and treating the patient’speriodontal disease, the periodontist may decide toeliminate periodontal pockets surrounding some teethand determine other teeth are nonrestorable. Thepatient is referred to the oral surgeon for removal ofthese nonrestorable teeth. The periodontist maydetermine that other periodontal problems can bealleviated by having a general dentist remove andreplace faulty restorations. In some situations, theservices of the orthodontist may be required toreposition malposed teeth.

Since periodontal disease affects the supportivestructures of the teeth, the primary function ofperiodontal treatment is (a) to eliminate theinflammation and arrest the progress of the disease and(b) perform periodontal treatment. Several reasons toeliminate pockets are as follows:

Food, bacterial accumulation, and infection canexist in pockets that form around the teeth.

Conditions, such as loss of gingival covering,can lead to exposure of the root and caries canoccur.

Inflammatory changes in the gingiva mayincrease the susceptibility to necrotizingulcerative gingivitis (NUG). Note: NUG iscaused by bacteria usually in the presence ofsecondary factors such as stress, smoking, and orlack of rest.

Inflammation from the pocket walls can causebone loss.

Discomfort can occur during mastication.

INDICATIONS ANDCONTRAINDICATIONS

Most periodontal diseases are characterized byinflammation that initially affects the gingiva.Advancement of the inflammatory process, if notstopped, may proceed to cause damage to periodontalligament tissue and alveolar bone. Inflammatorydiseases confined to the gingiva are termed gingivitis,whereas those that cause damage in the deepersupporting structures are classified as periodontitis.

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Early signs and symptoms of periodontal diseasefound in the interdental papilla and marginal gingivainclude the following:

Redness

Tendency to bleed easily

Evidence of exudate

Tenderness

Sponginess

Slight swelling

Probing depth of pockets

such as bone loss around the teeth, calculus, poormargins and overhangs on restorations, and open toothcontacts that are visible. In addition to radiographs,some dentists may take clinical photographs of theirpatient's mouth and in some cases, diagnostic studycasts are made.

CHARTING

Periodontal treatment is indicated when aperiodontal condition cannot be eliminated throughpreventive care, including prophylaxis, and improvedoral hygiene and diet. Resorption of the alveolar boneand the periodontal tissues are also indications fortreatment. If the progress of the disease is stopped, theteeth may have adequate support for retention. Forsuccessful periodontal treatment, a patient must bewi l l ing to accep t t r ea tmen t and fo l low therequirements necessary to maintain good oral hygiene.

Several situations contraindicate periodontaltreatment. A patient in poor general health with a poorprognosis for successful treatment and healing is oneexample. Another would be a patient with an extensiveinfection within the periodontium and/or bone loss tooextensive to provide support for the tooth followingperiodontal surgery. Periodontal treatment isdefinitely contraindicated if the patient has a negativeattitude and unwillingness to cooperate in establishingand maintaining good oral hygiene and nutrition.

EXAMINATION, CHARTING, ANDTREATMENT PLAN

The initial examination of the periodontal patientincludes thoroughly reviewing the pat ient 'smedical/dental health history, dental treatment history,and radiographs; charting of periodontal probingdepths, occlusion, and tooth mobility; and determininga treatment plan.

The review of the patient's medical-dental healthhistory provides valuable information regarding thedental status of the patient, such as past dentaltreatment, the patient's oral hygiene habits, andattitude toward dental health. A current full series ofperiapical radiographs and vertical bite-wings arenecessary for a thorough periodontal examination.Radiographs are extremely useful in the diagnosis andtreatment of periodontal disease because of conditions

Your p r imary r e spons ib i l i t y du r ing theexamination is to record the findings as the dentistdictates them. The results of the examination arerecorded on a NAVMED 6600/2, Periodontal Chart.This two-sided form (figs. 6-1 and 6-2) provides apermanent record of the examination, diagnosis, andtreatment plan for initiation of each new course oftherapy for the treatment of periodontal disease.

The form is an anatomical chart that containsdiagrams of the teeth with spaces for comments. Itpermits documentation of changes in the teeth,occlusal relations, soft tissue alterations, andinformation gained from radiographs. The findingsrelated to the teeth that are charted include missing,unerupted, malpositioned, or replaced teeth, dentalcaries, open or poor contacts, defective or poorrestorations, food impaction, pain on percussion, andplunger cusps. Findings of the periodontium includethe gingival level on the tooth, areas of recession orclefts, gingival enlargement or craters, probing depths,frenum attachments, furcation invasion (diseaseextension between the roots of multirooted teeth),bleeding and purulence points, tooth resection, andtooth mobility.

Instructions and symbols for charting are locatedin the left column on the front page. Charting notationsfor the front section are made in blue pencil, red pencil,and regular black pencil.

Use black ink on the following front sections:Place of examination, examiner, date, and patientidentification section. Also record the reverse sideinformation in black ink.

Pocket Depth

One of the most important findings in theperiodontal examination are the probing depths of thegingival sulcus or periodontal pockets. The dentistdetermines these measurements using a periodontalprobe calibrated in millimeters. The dentist inserts theperiodontal probe into the gingival sulcus to the depthof the epithelial attachment. The distance between theattachment and the gingival margin is measured and

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Figure 6-1.—NAVMED 6600/2 (Front page).

recorded. Six measurements are made of the gingivalsulcus or pocket depth on each tooth: three on the facialand three on the lingual. The dentist walks the probearound the tooth for the three measurements on thefacial surface of each tooth in the arch which includethe distofacial, facial, and mesiofacial (fig. 6-3). Thedentist repeats the probing procedure for the threemeasurements on the lingual surfaces of each tooth in

the arch: distolingual, lingual, and mesiolingual. Thedentist repeats the probing process for the oppositearch.

Mobility

With the progression of periodontal disease,supporting bone structure that anchors the tooth inplace may be destroyed. This will make the teeth

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Figure 6-2.—NAVMED 6600/2 (Back page).

become loose (mobile). The dentist tests each tooth formobility by using the handles of two mirrors to push itin a facial-lingual direction and pressing on theocclusal or incisal surface. A scale of one to three (I, II,and III) is used to describe and record mobility.

Class II—Moderate mobility

(within lmm of total movement)

Class III—Extensive mobility

(greater than lmm in al l direct ions or

Class I—Slightly greater than normal depressible)

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Figure 6-3.—Walking the periodontal probe around the tooth.

TREATMENT PLAN

Once the front of the NAVMED 6600/2 is charted,the areas of the back of the form are completed by thedentist. The tentative treatment plan outlines thedentist's recommended treatment for the patient andthe sequence in which it is done. The dentist mustdiscuss the diagnosis, prognosis, and tentativetreatment plan with the patient. It is up to the patient toaccept or decline the recommended treatment. Theexamining dentist, facility, and dates are on the frontpage of the NAVMED 6600/2, which becomes apermanent part of the patient’s dental record. After theexamination is completed, appointments are arrangedwith the patient for treatment.

BASIC PERIODONTAL INSTRUMENTS

Several instruments are commonly used inperiodontal treatment. Among them are probes,scalers, curettes, hoes, files, chisels, and knives.Although we have discussed some of these instrumentsin other specialties, the instruments discussed here aredesigned for periodontal use and are somewhatdifferent. Some of the instruments are used for scalingand root planing, while others are used for periodontalsurgery.

PERIODONTAL PROBES

The periodontal probe is one of the most importantinstruments used to make a diagnosis and accuratelydetermine the presence, depth, and form of periodontal

pockets. An angled shank places the working end atabout a 45° angle in relation to the handle. The thinnarrow working end is inserted gently to the depth ofthe periodontal pocket. Calculus may interfere withaccurate probing. A periodontal probe is an elongatedand tapered instrument that is scored at millimeterintervals on the working end. The scored markingsmake it easy to determine the depth of the pocket. Themarkings can range in increments from 1 to 10mm,depending on the type of the probe. Many differenttypes of probes are used. Figure 6-4 illustrates acommon periodontal probe

FURCATION PROBES

When periodontal disease causes sufficient loss ofa t t a c h m e n t a r o u n d m u l t i r o o t e d t e e t h , t h einterradicular bone (furcation area) may becomeinvolved. The presence of gingiva and neighboringteeth frequently prevent accurate probing of thefurcation area with the standard periodontal probe.The furcation probe shown in figure 6-5 is adouble-ended instrument designed to help determinethe extent of the interradicular bone loss.

SCALING AND ROOT PLANINGINSTRUMENTS

The term scaling is used to identify the removal ofcalculus (mineralized plaque) from the surface of atooth. Scaling can be supragingival (performed byDental Technicians) or subgingival (performed by ahygienist or a dentist), depending on the location of the

Figure 6-4.—Periodontal probe.

Figure 6-5.—Furcation probe (double-ended).

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calculus relative to the gingival margin. The objectiveof scaling is to remove calculus from the tooth surface.This is easy to accomplish when the calculus is locatedon the enamel of the tooth. Calculus attached to theroot surface, however, is embedded in the surfaceirregularities and is much more difficult to remove.The dentist or hygienist will smooth out theirregularities and remove the calculus. As this is done,some root structure is removed. This is referred to asroot planing. Several instruments have been designedfor scaling and root planing. They include sickles,curettes, files, chisels, and hoes (illustrated in figure6-6). We will discuss dental implant scalinginstruments.

Sickle Scalers

A sickle scaler (fig. 6-7) is primarily designed forremoval of supragingival calculus. Sickles withstraight shanks are designed to adapt to anterior teeth,and those with contra-angled shanks (calledJacquettes) adapt to posterior teeth and are illustratedin figure 6-8. The basic characteristics of the sicklescaler are they are triangular in shape, have two cuttingedges, and are pointed at the tip. The cutting edge is Figure 6-7.—Sickle scaler.

Figure 6-8.—Jacquette double-ended scaler.

inserted under the ledge of calculus and used with apull stroke.

Curettes

The curette is the instrument of choice forsubgingival calculus removal, root planing, andremoving soft tissue from the periodontal pocket. TheFigure 6-6.—Scaling and root planing instruments.

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working ends of curettes form a spoon-shaped face anda rounded back. In a cross-section, the curette bladeappears semicircular rather than triangular (shape ofthe sickle scaler). Two basic types of curettes are theuniversal and the area specific.

UNIVERSAL CURETTE.—The universalcurette is a paired instrument designed to adapt to mostareas of the dentition by altering and adapting thefinger rest, fulcrum, and hand position. Two parallelcutting edges are formed, one on either side of the face.Either cutting edge can be used. Universal instrumentscome in a variety of sizes and shank lengths. Somecommonly used instruments are the Columbia #13/14and the McCalls #13/14 and #17/18. The Columbia#13/14 has a true universal application, whereas theMcCalls has two cutting edges on each blade that arebetter suited to certain areas of the mouth. The McCalls#13/14 are best suited for use on bicuspids and the#17/18 for molars (fig. 6-9).

AREA SPECIFIC.—Area specific curettes differfrom the universal curettes in several ways. First, theyare a set of several instruments designed and angled toadapt to a specific anatomic area of the dentition.Second, these curettes are designed with only onecutting edge. Area specific curettes are the best choicefor subgingival scaling and root planing because theyprovide the best adaptation to the complex rootanatomy.

each Gracey is used on the tooth surface being scaled

The Gracey curettes are paired, area-specificinstruments, that have similar blades with differentangulations and contra-angulations of the shank.Figure 6-10 i l lustrates the complete set ofdouble-ended Graceys. Next we will discuss where

Figure 6-9.—McCalls curettes. or root planed.

Figure 6-10.—Gracey area specific curette set.

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Gracey #1/2—Facial root surfaces of incisorsand cuspids.

Gracey #3/4—Lingual surfaces of anterior teeth.

Gracey #5/6—All surfaces of anterior teeth andsome bicuspids.

Gracey #7/8 and #9/10—Facial and lingualsurfaces of posterior teeth.

Gracey #11/12—Mesial surfaces of posteriorteeth and for furcations and depressions.

Gracey #13/14—Distal surfaces of posteriorteeth.

Files

Periodontal files are strong instruments used tocrush large calculus deposits and to smooth the toothsurface at the cementoenamel junction when thedentist is root planing.

Chisels

Use of the periodontal chisel scaler is extremelylimited. It is used solely for the removal of heavysupragingival calculus deposits that bridge openinterproximal spaces of anterior teeth.

Hoes

Periodontal hoe scalers are usually limited toremoval of large ledges of calculus locatedsupragingivally and slightly subgingivally. Forexample, calculus that rings the tooth on the facial,lingual, and distal surfaces of teeth that have noadjacent posterior teeth can be removed with the hoe.

Figure 6-11.—Plastic or nonmetallic scaling instruments.

Lingual scaler—Designed for cleaning thelingual side of the abutment.

Posterior scaler—Designed to enable access tothe posterior lingual abutment surfaces.

Buccal scaler—Cleans the buccal surface of theabutment.

PERIODONTAL SURGERYINSTRUMENTS

To be an effective and efficient dental assistant,you must be familiar with the instruments the dentistmay use during surgery. Some of the most commonlyused periodontal surgery instruments are periostealelevators, periodontal knives, periodontal surgerycurettes and sickles, and periodontal surgery chisels,hoes, and files.

PERIOSTEAL ELEVATORS

The periodontal periosteal elevator illustrated infigure 6-12 is very similar in shape to the prostheticlaboratory wax spatulas. It is designed with one endthat is rounded and the other pointed for delicate tissueretraction.

PERIODONTAL KNIVESDental Implant Scaling Instruments

Special scalers made of plastic or nonmetallicmaterial are designed for cleaning the abutments ofdental implants. The special material enables optimumcleaning without damaging the abutment surface.Never use metal scalers and curettes, including someand or untrasonic tips, because they may damage thesmooth surface of the implant.

Several versions of implant scales are available topermit access in all situations. We will discuss whereon the tooth the implant scalers (fig. 6-11) are used.

Universal scaler—Can be used in most areas toclean the abutment surfaces and apical portion ofthe framework.

Periodontal knives (fig. 6-13) may be double- orsingle-ended in paired sets. The knives have a slightlyangled, crescent-shaped blade. Many different typesof knives are designed to make initial incisions forgingivectomy and gingivoplasty procedures. Otherknives are used to excise (complete the removal of) thein te rp rox ima l t i s sue in g ing ivec tomy andgingivoplasty procedures.

PERIODONTAL SURGERY CURETTESAND SICKLES

These instruments are larger and heavier curettesand sickles than those used in scalings and are oftenneeded during periodontal surgery. They are designed

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Figure 6-12.—Periodontal periosteal elevator.

Figure 6-13.—Periodontal knife.

t o r emove g ranu la t ion , f ib rous t i s sue , andhard-to-remove subgingival calculus deposits.

PERIODONTAL SURGERY CHISELS,HOES, AND FILES

Because of bone loss accompanied in some casesof periodontal disease, it may be necessary for the

periodontist to recontour the bone during periodontalsurgery. In such cases, the dentist may use periodontalsurgery chisels, hoes, and files. They are also largerand heavier than those used in scaling and root planing.

ELECTROSURGERY APPARATUS

Electrosurgery equipment uses a high-frequencyelectric current to cut tissue. The electrode attachmentused will depend on the extent of the tissue removalrequired. One advantage of using the electrosurgery iscoagulation and the control of bleeding.

ROUTINE PERIODONTAL PROCEDURES

Treatment of periodontal disease and occlusaltrauma may include several nonsurgical procedures,such as equilibration, periodontal scaling, scaling androot planing, and root desensitization. Gingivalcurettage, which is considered a periodontal surgeryprocedure, is commonly performed in conjunctionwith scaling and root planing.

OCCLUSAL EQUILIBRATION

Occlusal interferences and oral habits, such asbruxism and clenching, can cause the mandible to shiftout of its normal position when the maxillary andmandibular teeth occlude. This chronic shifting of themandible during oral functions is traumatic to the joint,and may cause muscle spasms, and hypersensitivityand hypermobility of teeth. The elimination ofocclusal interferences and establishment of favorableocclusal forces on the teeth is called occlusalequilibration. The two types (limited or complete) arediscussed below.

Limited Occlusal Adjustment

Limited occulusal adjustment involves reshapingthe occlusal or incisal surfaces of the teeth by grindingto improve inter-arch tooth contact relationships. Thistype of adjustment is limited to one or more selectiveteeth being reshaped.

Complete Occlusal Adjustment

Complete occlusal adjustment involves reshapingthe occlusal and or incisal surfaces by grinding toachieve correct contact during functional movement(grinding side- to-side and sliding the jaw forward). Acomplete adjustment involves all or nearly all of theteeth.

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Materials and Procedures PERIODONTAL SURGERY PROCEDURESOF THE SOFT AND HARD TISSUES

You will need to prepare a tray with a mirror,explorer , periodontal probe, cotton forceps,articulating paper forceps, various rotary stones,rubber wheels and points, high-speed handpiece,articulating paper, occlusal waxes, and gauze sponges.An occlusal equilibration may require that a study castbe made to determine where the occlusion must beadjusted. During the procedure, the dentist usesarticulating paper or occlusal wax on the patient's teethfor an accurate registration of occlusal contacts. Youwill use the gauze sponges to wipe off marks and keepthe teeth dry to assure the accuracy of marking. Thedentist removes the occlusal interferences byselectively grinding the teeth with a diamond stone inthe high speed handpiece. The occlusion is recheckedand the adjusted tooth surfaces are polished withabrasive rubber wheels or points.

Periodontal surgery procedures involving thesoft tissue include gingivectomy, gingivoplasty,periodontal flap, and soft tissue graft procedures.Surgery of the hard tissue includes osseous surgery,metallic implants, root amputations, hemisections, andbicuspidization. Your responsibilities in periodontalsurgery are similar to those of oral surgery. To properlycarry out your duties, you must know whichinstruments and instrument packs the periodontistdesires. You should have all instruments and suppliesneeded for the particular periodontal treatment set upbefore the arrival of the patient. A typical periodontalsurgery tray is shown in figure 6-14.

GINGIVECTOMY

PERIODONTAL SCALING, ROOTPLANING, AND GINGIVAL CURETTAGE

These three procedures are often performed by thedentist or hygienist in conjunction with one another todecrease periodontal inflammation. Scalingprocedures performed independently involve thecomplete removal of supra- and sub-gingival calculusand bacterial debris with hand instruments ormechanical (ultrasonic) instrumentation. Thisprocedure is usually done by sextants or quadrants ofthe patient's mouth.

Gingivectomy is the surgical excision of the softtissue wall of suprabony pockets (above the alveolarbone) to eliminate periodontal pockets. The procedureis limited to gingival pockets where a wide band ofattached gingiva exists. This surgery results in gingivalrecession and may expose tooth roots . If agingivectomy is indicated, the gingival tissue shouldfirst be cleared of acute infection. Gingivectomy maybe performed with either a scalpel or periodontal knife.

GINGIVOPLASTY

Scaling and root planing performed togetherinvolve more extensive scaling procedures to removesubgingival calculus located in the periodontal pocketsand smoothing of root surfaces. Scaling and rootplaning procedures usually are done by sextants orquadrants of the patient's mouth with local anesthetic.

This procedure involves the reshaping of gingivaldeformities to improve form and function. Thistechnique is useful when gingival overgrowth orgingival craters exist. A gingivoplasty is done toremove excess tissue and recontour the gingiva.Gingivoplasty may be performed with a periodontalknife, a scalpel, or electrosurgery.

PERIODONTAL FLAPS

Gingival curettage is the intentional removal ofthe soft tissue wall of a periodontal pocket done underlocal anesthesia.

A periodontal flap is a technique used in an attemptto correct gingival defects. With the flap technique, asection of the gingiva and or mucosa is surgicallyseparated from the underlying tissues. The roots arethoroughly planed and the gingiva is repositioned tocorrect a gingival defect and sutured into place.

ROOT DESENSITIZATION PERIODONTAL SOFT TISSUE GRAFTS

Periodontal patients may experience rootsensitivity when elimination of periodontal pocketsexposes root surfaces. Root desensitization involvesthe application of agents or drugs to exposed rootsurfaces to reduce or eliminate dentinal sensitivity.

A soft tissue graft involves the complete separationof tissue from the donor site and placement in anotherlocation to correct periodontal or mucogingivaldefects. You must exercise special care to avoidaspiration of the tissue graft with the suctionequipment.

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Figure 6-14.—Periodontal surgery tray.

OSSEOUS SURGERY craters. Several surgical procedures are designed to

As inflammation proceeds into the deepertreat these defects.

supporting tissues, the bone resorbs, creating defectsor deformities. The most common deformities occurinterproximally as saucer-shaped defects, known as

Osteoplasty —Refers to reshaping thealveolar bone without removing toothsupporting bone.

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Ostectomy—Includes removal of toothsupporting bone in the treatment of periodontaldisease.

Osseous reconstructive surgery—This involvesprocedures involving regeneration (regrowth) oflost bone, and the reestablishment of theperiodontal ligament, cementum, gingivalfibers, and junctional epithelium.

An osseous graft is a procedure that involvesimplanting living tissue or inert material intoperiodontal osseous defects to regenerate newperiodontal attachment (bone, periodontal ligament,and cementum). Donor bone may be obtained fromadjacent cortical and cancellous bone, mixed with thepatient's blood. Other sources for bone may be fromedentulous ridges, extraction sites, or maxillarytuberosity. Bone can also be obtained from tissuebanks or various crystalline synthetic substances, suchas hydroxyapatite over a 4-6 month period. Grafts mayalso be placed in osseous defects.

METALLIC IMPLANTS

A method of tooth replacement involves thesurgical implantation of coated metal implants intothe bone ridges of edentulous areas (fig. 6-15). Theroot implant becomes firmly attached to the bone anda new crown is placed upon it to support fixed orremovable bridges. The procedures involved in theuse of metallic implants require a team approach fromthe prosthodontics, periodontic, and oral surgeryspecialties.

ROOT AMPUTATION, HEMISECTION,AND BICUSPIDIZATION

Sometimes the bone loss is so great around the rootof a mutlirooted tooth that a root or section of the tooth

Figure 6-15.—Implant placement.

must be removed. The remaining portion of the toothcan be saved if sufficient periodontal support ispresent. Endodontic treatment is required beforetreatment of the remaining portion of the tooth.

Root amputation—The complete removal of oneor more roots of a multirooted tooth, without removal ofany portion of the crown.

Hemisection—The surgical sectioning of amultirooted tooth through the furcation area so that theblocked, defective, or periodontally involved root orroots may be removed along with the associated portionof the crown. An artificial crown is required on theremaining half of the crown.

Bicuspidization—A multirooted tooth issectioned through the furcation and both halves of thetooth are retained.

SURGICAL DRESSINGS

During periodontal surgery, the dentist exposessoft tissues and sometimes bone, leaving open wounds.Surgical dressing materials (packs) are usually appliedto the wounds as a protective barrier. These packs notonly protect the area by preventing food from injuringthe surgical area, but also soothe and aid in the healingprocess. Your primary duty will be to mix theingredients and form the dressing the dentist places inthe patient's mouth. Follow the manufacturer'sinstructions for mixing. Most dressing will stay inplace for 5-7 days. During the postoperative visit, thesurgical dressing and any sutures will be removed. Thedental officer may elect to place another dressing overthe surgical area if the healing process is delayed.

INSTRUMENT SHARPENING

Periodontal cutting instruments must be kept sharpby a correct sharpening technique. To be able torecognize when instruments require sharpening isextremely important. To determine if an instrument issharp, you must be familiar with each instrument'scutting edge(s). Under good lighting, examine thecutting edge using a magnifying glass, or by lookingdirectly at the edge while slightly turning theinstrument. A sharp cutting edge will not reflect lightand appears as a line. A dull edge will reflect the light,creating a glare because the edge has been rounded off.

SHARPENING DEVICES

The correct sharpening device is critical for a goodcutting edge. Hard felt wheels are recommended for

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periodontal knives. Sharpening stones are recommendedfor curettes, chisels, and scalers.

Sharpening stones are available in various grits(textures) and designs to meet a particular need. TheRuby and Arkansas stones are the most commonlyused. The Ruby stone is fairly course, cuts rapidly, andis used primarily for initial sharpening of very dullinstruments. The Arkansas stone has a fine grit and isused to attain a sharp edge.

Depending on their design and method of use,sharpening stones are either mounted or unmounted.Some are mounted on mandrels for insertion into thedental handpiece, others are mounted in mechanicaldevices known as mechanical sharpeners. Unmountedstones may be rectangular, cylindrical, or have aspecial shape. These stones are often lubricated withwater or oil to avoid clogging the stone’s pores withmetal particles as the instrument is ground.

Regardless of the device used, instruments aresharpened by grinding or polishing the surfaces thatform the cutting edge. Instruments should besharpened after every use. If the cutting edge has beenmarkedly reduced because of sharpening, discard theinstrument rather than risking the chance of breaking itduring a treatment procedure. Keep in mind that theamount of metal ground away by mounted stones ismuch greater than that removed by unmounted stones.

PERIODONTAL KNIFE SHARPENING

The most commonly used periodontal knives arethe Kirkland #15 and #16, and the Orban #1 and #2.Both types may be sharpened with a hard felt wheelmounted on a dental lathe or handpiece. It is difficult tomaintain the knife’s functional shape and blade bevelwith either technique.

Kirkland knives have three cutting edges tosharpen, the inner, outer, and back edge (figure 6-16).The Orban knives have only two cutting edges, theinner and outer edges (figure 6-17). Apply an abrasive,such as chrome rouge, to the felt wheel to aid in thesharpening process. Sharpen both sides of each edge.Use the following technique:

Hold the knife handle between your thumbs andforefingers (both hands). Stabilize your hands or elbowson the work bench.

Hold the knife so that the felt wheel rotates awayfrom the cutting edge.

Figure 6-16 .-Kirkland knife cutting edges: inner (1), outer(2), and back (3).

Figure 6-17.—Orban knife cutting edges: inner (1) andouter (2).

Place the knife against the wheel at an angleconsistent with the bevel of the blade. Gently apply theknife to the wheel. Sharpen both sides of each cuttingedge. Check each edge for sharpness.

If using a stone, establish the same alignment aswith the felt wheel, then draw the stone across the bevelof the blade.

PERIODONTAL CURETTE SHARPENING

Curettes are the most commonly used scalinginstruments. McCall curettes (universal curettes) havetwo cutting edges and are sharpened on both sides.Gracey curettes are sharpened only on the outer curve.

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Both have a rounded tip that must be maintained duringsharpening (except the McCall #13/14).

When using a stationary stone, hold the curette in amodified pen grasp and establish a finger rest at theedge of the stone. Draw the side of the blade towardyou. Because the curette is curved, you must repeat thisprocess until the entire arc of the cutting edge issharpened. Be sure to lubricate the stone during thesharpening procedure.

When sharpening a curette on a mounted stone, besure the wheel rotates away from the side of the blade.

PERIODONTAL CHISEL SHARPENING

The No. 1 and No. 2 Ochsenbein chisels are themost commonly used periodontal chisels. They havethree cutting edges, a flat edge on the tip and a curvededge on each side of the tip. The edges to be sharpenedare up, toward you, on the convex side of the chiselhead. The cutting edges on the No. 1 Ochsenbein arereversed. They are on the concave side of the head.Another commonly used chisel, the TGO chisel, is asmaller version of the Ochsenbein chisel. Follow thesesteps when sharpening a periodontal chisel:

the tip of the chisel. Position the blade on the stone at anangle conforming to the bevel of the blade. Push theblade across the stone in the direction of the cuttingedge.

Use a flat Arkansas stone to sharpen the edge on

Use a cylindrical sharpening stone or one withrounded edges to sharpen the curved edges on the sidesof the chisel head. Position the stone on the blade at anangle consistent with the bevel of the blade. Twist orrotate the stone until the edge is sharp.

DO NOT rotate the sharpening stone over thecutting edge, it will round and dull the edge.

SCALER SHARPENING

Sickle scalers and hoes are the most commonlyused scaling instruments. Sickle scalers have twocutting edges that form a point where the facial andlateral surfaces meet (figure 6-18). Sharpen the sicklescaler by grinding the facial and lateral surfaces on astationary stone being careful to maintain the sharppoint.

To sharpen the facial surface, hold the edge flatagainst the side of the stone and draw the instrumentback and forth.

To sharpen the lateral surface, position the surfaceagainst the stone and draw the instrument across thestone in the direction of the cutting edge. Repeat thisprocedure until both lateral surfaces are sharp.

A hoe scaler has only one edge. Sharpen the hoe bygrinding only the outer surface of the cutting edge. Theouter surface and inner blade surfaces form a 45°angle, so you must maintain this angle against thestone. Draw the instrument across the stone in thedirection of the cutting edge. Repeat this procedureuntil the edge is sharp.

Figure 6-18.—Sickle sealer: A. Tip of sickle sealer; B. Crosssection.

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CHAPTER 7

ENDODONTIC ASSISTANCE

DENTAL SPECIALTY OFENDODONTICS

Before major advances in the treatment of diseasesof the dental pulp and periapical tissues were made,dentists extracted many teeth needlessly. Endodonticsis the dental specialty primarily concerned with thesediseases. In some dental clinics, an endodontist isassigned exclusively to this specialty. Often, some ofthe restorative dentists spend part of their time seeingpatients who require endodontic treatment, also knownas root canal therapy. As a basic dental assistant, youmust be familiar with the following aspects ofendodontics:

Functions, causes, and diagnosis

Types of procedures

Steps in pulpectomy and root canal treatment

Steps in apicoectomy and associated procedures

You must also be able to identify:

Endodontic instruments

Endodontic materials

Endodontic equipment

When involved with endodontic procedures, youmust follow BUMEDINST 6600.10, Dental InfectionControl Program. Strict compliance to steriletechnique, sterilization, and disinfection is absolutelyessential in endodontic treatment.

FUNCTION

The primary purpose of endodontics is thetreatment of diseases of the pulp and periapical tissues.The goal of this treatment is to retain the natural teethrather than extract them. Often, the endodonticpatient’s initial appointment is of an urgent naturebecause of the associated pain or infection.Understanding the causes of pulp disease and how adiagnosis is reached will increase your ability to be aneffective endodontic assistant.

CAUSES

The dental pulp can be injured in several ways.Some injured teeth can be treated and returned to

normal. Other injured pulpal tissue may undergonecrosis (die) after the slightest injury. Some of themost common causes of injury to the pulp includedental caries (covered in Dental Technician, Volume 1,NAVEDTRA 12572, chapter 5, "Oral Pathology"),traumatic blows to the teeth, pulp exposure (covered inDental Technician, Volume 1, NAVEDTRA 12572,chapter 6, "Emergency Treatment of Oral Diseases andInjuries"), chemical irritation, and thermal irritation.

Traumatic Blows

Traumatic blows to the teeth can result fromsituations such as common household accidents, autocollisions, or athletic injuries. A sharp blow to one ormore teeth can result in fracture of the crown or root, oreven the avulsion (forcefully knocked out of thesocket) of the complete tooth, cutting off the bloodflow to the pulp.

Chemical Irritation

Chemical irritation after placement of certainchemical substances commonly used in restorativeprocedures can cause pulp injury or death. Anothercause of chemical irritation is a faulty restoration,which allows oral fluids to leak between the restorationand dentin.

Thermal Irritation

Thermal irritation can cause pulp injury andpatients will experience discomfort when they inhalecold air through their mouths. If metallic restorativematerials are placed close to the pulp, the patient w-illexperience thermal irritation.

DIAGNOSIS

The diagnosis of pulp and periapical conditionsmust precede the treatment. Endodontic diagnosis is aresult of the skillful use and interpretation of severalmethods. Some of the more common methods arediscussed in the paragraphs that follow.

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Dental History

The patient's dental history is a valuable aid to thedentist. It provides communication between the dentistand the patient, and allows the dentist to trace thehistory of the complaint through symptoms describedby the patient. Often, patients reveal valuableinformation regarding previous injuries to the teeth,even though they may have occurred many yearsearlier.

Clinical Examination

A clinical examination of the oral cavity allows thedentist to visually inspect the patient's mouthproviding clues to the nature of the patient's problems.Such clinical signs as discoloration of the teeth, crownfracture, gross caries, swelling, abnormal soft tissue,and a draining abscess can be identified during aclinical examination.

Radiographs

Radiographs of the teeth and bone are one of themost valuable diagnostic tools the dentist has toevaluate structures that cannot be seen by clinicalexamination, such as the pulp and periapical tissues.The presence of bone loss in the periapical area inresponse to a necrotic pulp can be detected on aradiograph as a dark area surrounding the apex of theroot. The presence of this dark area, or radiolucency,on a dental radiograph is an important feature used todiagnose pulp and periapical disease. Periapicalpathology appears as radiolucencies on a radiograph.

Radiographs can also reveal possible causes ofpulpal injury before bone resorption occurs. Rootfractures, deep caries, and previous pulp exposures aresome examples of possible causes of pupal injurydetected on a radiograph. An accurate radiograph canreveal root length, abnormal root curvature, andabnormal calcification, which is helpful information indetermining if the tooth can be treated endodontically.A radiograph, properly exposed and processed, canlast indefinitely and provide a permanent record of thecondition of the patient and be used for futurereference. Comparison of the initial radiographs withpostoperative radiographs is a valuable index todetermine if the treatment was successful.

Pulp Testers

Two of the common pulp testers used primarily todetermine whether the pulp is vital or necrotic

(nonvital) are shown in figure 7-1. Electric current isused to stimulate nerve fibers in the pulp through thedentin layer. General information about the status ofthe pulp is obtained by comparing the response of asuspected tooth with that of a normal tooth (controltooth) of the same type on the opposite side of themouth. The amount of current delivered to a tooth isindicated by a numerical scale. The patient holds theends of the probe to complete the circuit. Highernumbers on the scale indicate that more current isdelivered to the tooth. As the current is increasedgradually, the patient is instructed to let go of the probewhenever a sensation is first detected within the tooth.

Generally, the sensation is described as a slighttingling or warm feeling. The number at which aresponse occurs is recorded and compared with the testresults of the control tooth. A tooth with a necrotic pulpwill not respond to even the most intense electricalstimulation. A dying pulp can produce a variety ofresponses, depending on the state of the pulp at thetime of the test. However, the number readings arerelative and cannot be used to diagnose vital pulp.

Thermal Sensitivity Test

The thermal sensitivity test exposes a tooth toextremes in temperature and provides an accuratemethod of identifying the problem tooth, as well asdetermining the status of its pulp. The two mostcommon diagnostic tests are cold and heat.

COLD TEST.—The cold test can be done easilyby placing a cylinder or stick of ice on the tooth. First,the suspected tooth is isolated and dried, then the icestick, held in a gauze square, is applied to the cervicalarea of the tooth. Healthy teeth will respond positivelyto a cold stimulus, but the sensitivity should resolvequickly. If the pulp is inflamed, the patient will

Figure 7-1.—Two common pulp testers.

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experience a lingering sensation to cold. Other coldtest materials that can be used are ethyl chloride andskin refrigerants.

HEAT TEST.—The heat test consists of isolatingthe suspected tooth with a rubber dam and applying awarm liquid (hot water or coffee) to the tooth. Thewarm liquid should not be hotter than 140°F andshould not burn your skin. If the tooth reacts with apainful response that lingers a few seconds after theheat is removed, pulpitis may be present. If the patientexperiences a violent pain reaction to the heat and isrelieved by a cold application, the pulp is irreversiblyinflamed and will need a root canal. If the patientexperiences no response to heat or cold, the pulp isnecrotic.

Percussion

Percussion is the gentle tapping of the crown of thetooth with the finger or the end of a mirror handle todetermine the presence of periapical inflammation. If apatient has an acute inflammation at the apex of theroot, percussion stimulates the already inflamed areaand pain results. An abnormal dull sound may signify aroot that has attached to the bone. Several normal,opposing, and adjacent teeth should be checked forcomparison.

Palpation

Palpation is the application of the finger with lightpressure to areas of the mouth to detect normal orabnormal tissue. Swelling, pain, and degree of rigidityof tissues are determined by palpation. When usingpalpation in the diagnosis of periapical diseases, thefingers are pressed gently against the soft tissueoverlying the bone and apexes of the teeth to comparethe tissues.

Mobility Test

The mobility test is done by moving the toothbetween the handles of 2 instruments. Abnormalmobility of a tooth when compared to healthy teethsignifies temporary or permanent loss of supportingalveolar bone or trauma. Mobility of the tooth tends toincrease if an infection or injury is long standing andhas affected the supporting periodontium tissues.

Selective Anesthesia

Selective anesthesia can be of assistance if thepatient cannot accurately determine which teeth are the

source of discomfort. If other diagnostic tests havenarrowed the choice down to two teeth, one tooth canbe anesthetized to determine if the pain disappears. Ifthe pain does not disappear until the second tooth isanesthetized, the second tooth is the probable source.Selective anesthesia is most effective when the choiceis between a maxillary and a mandibular tooth.

Transillumination

Transillumination uses fiber optic lighting toallow an intense, concentrated light to pass through thetooth from the lingual to the facial aspect. This is donemost effectively on anterior teeth because of theirstructure and location in the arch. The light transmitsthrough the enamel and dentin, permitting thedetection of caries or a fractured crown.

TYPES OF PROCEDURES

There are several types of endodontic procedures.The more common procedures include pulp capping,pulpotomy, pulpectomy, and root canal therapy.Occasionally other procedures such as incision anddrainage, apicoectomy, periapical curet tage,retrograde filling, root amputation, and bleaching ofteeth are indicated.

PULP CAPPING

In an attempt to protect the pulp against additionalinjury and stimulate pulp regeneration, an applicationof protective dressing, such as calcium hydroxide, isplaced over an exposed or nearly exposed vital pulp.This treatment is referred to as pulp capping. Whenthe pulp is exposed mechanically during toothpreparation, placing a pulp cap directly over theexposed pulp is referred to as a direct pulp cap. If deepcaries are present and a danger of exposing the pulpexists, placing a pulp cap over a layer of remainingdentin is termed an indirect pulp cap. If pulp cappingin not effective, the pulp can be treated withendodontic therapy.

PULPOTOMY AND PULPECTOMY

A pulpotomy is the surgical removal of the coronalpart (pulp chamber) of an exposed vital pulp. The pulpis retained in root canals with the exposed endscovered with applications of calcium hydroxide, zincoxide and eugenol, and zinc phosphate cement topreserve its vitality and function. If indicated, rootcanal treatment is completed at a later date.

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The most common endodontic procedure is thepulpectomy, which is the removal of the entire pulp(chamber and canal). After removal of the pulp, rootcanal therapy is performed.

ROOT CANAL THERAPY

This t r ea tmen t cons i s t s o f the in t e rna ldebridement, cleaning, shaping, and permanent fillingof the root canal system. During the therapy, the dentistmay place medications and temporary filling material.The therapy may vary slightly because of the type oftooth and number of canals in the tooth.

INCISION AND DRAINAGE

An acute periapical abscess may indicate a needfor incision and drainage to eliminate the infectionalong with endodontic treatment. Incision anddrainage can be effective when the swelling andinfection are localized in the alveolus with a clearlydefined point on the surface of the mucosa. Endodontictreatment Should be initiated at the same appointmentto remove the necrotic infected pulp. Although theperiapical abscess usually is accompanied by severepain, it is not advisable to inject a local anestheticsolution directly into the infected area when drainingthe abscess because of the danger of spreading theinfection. Instead, block anesthesia and infiltrationaway from the infected area. Local anesthesia may notbe as effective because of changes in the pH of thetissues in the presence of the infection. The patientmust be informed to expect momentary discomfortwhen the area is lanced, but the pain is immediatelyand significantly reduced after the incision is made andthe exudate (pus) is expressed. If indicated, a drain isplaced to provide short term drainage and to preventthe opening from closing prematurely until theinfected area drains. The dentist may prescribeantibiotics. Once the infection is controlled and theswelling and tenderness subside, the dentist will treatthe tooth endodontically.

APICOECTOMY AND PERIAPICALCURETTAGE

An apicoectomy (root end resection) is the surgicalremoval of the apical portion of the tooth through asurgical opening made in the overlying bone andgingival tissues. An apicoectomy usually is performedin conjunction with periapical curettage after the bodyfails to heal after endodontic treatment. Periapicalcurettage is the surgical removal of apically inflamed

tissue associated with the tooth through an openingmade in the overlying bone and gingival tissues.Treatment is limited to curettage of the area to removeall diseased material. Conditions that may indicate theneed for an apicoectomy include:

Persistent, local infection following endodontictreatment.

Canal filling materials or medications extrudedinto the periapical tissue.

A broken instrument lodged in the canalpreventing complete filling.

Obstruction caused by a calcified root canal.

Extreme curvature of the canal preventingaccess to the apex of the root.

Root canals that are unfilled or debrided.

RETROGRADE FILLING

This is a method of sealing the apical end of theroot canal by placing a restoration in the root apex.This is usually done in conjunction with theapicoectomy. Superortho-ethoxybenzoic acid (EBA)cement or an intermediate restorative material such asZinc Oxide and Eugenol (ZOE) is used as the fillingmaterial because they will not react with any moisturethat may be present in the root canal. Some dentistsprefer to use composite filling material.

ROOT AMPUTATIONS

Occasionally, a multirooted tooth requiringendodontic treatment may have a root that isimpossible to obtain an adequate apical seal or isaffected by periodontal disease. When the other rootsof the teeth are treatable, rather than extracting theentire tooth, the untreatable root is amputated andremoved. The opening to which the amputated rootwas attached is sealed with amalgam similar to that ofan apicoectomy procedure. The retained section of thetooth is treated endodontically before amputation.

BLEACHING OF DISCOLORED TEETH

The use of chemical agents may be used to removediscoloration from the crowns of vital or nonvitalteeth. Nonvital teeth may discolor because of pupalhemorrhage into the dentinal tubules after traumaticinjury of the tooth, or from the use of medications thatcause staining when used in endodontic therapy. Insuch cases, the appearance of the discolored teeth maybe improved dramatically by bleaching the tooth.

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STEPS IN PULPECTOMY AND ROOTCANAL TREATMENT

As in all efficient assisting, you will need toanticipate the dentist's needs. In endodontics, your dutiesconsist of such tasks as performing infection controlprocedures, preparing for the treatment, aiding in theplacement of the rubber clam, irrigating and aspirating toflush the area, mixing materials, and passing instruments.You will need to have knowledge of the treatmentprocedure and sequence to effectively anticipate thedentist's needs and to schedule appointments.

APPOINTMENT SCHEDULING

Root canal therapy may take one or moreappointments based on the number of canals andseverity of infection. Before a canal can be filled, thecanals must be completely cleaned. Filling the canalwhile infective organisms are still present may result innon-healing. A patient suffering from an acuteperiapical abscess may experience severe pain. Thepain is due to inflammation in the pulp canal, and/orperiapical tissues. The pressure, and therefore the pain,is relieved during the first step of endodontics when thepulp canal is opened. Once the pulp canal is opened,broaches can be used to remove intact pulp tissue fromthe canal. The canal is then irrigated, and debrided withfiles and reamers. Dry the canal and place smallmedicated cotton pellets into the pulp chamber to helpclear up the infection. Then, the dentist may place atemporary restoration.

During a second appointment, if necessary, thetemporary restoration is removed, the canals irrigated,and root canal reamers and files are used to enlarge,shape, and smooth the pulp canal. If infectioncontinues to be a problem, placement of medicationinto the canal, and placing a temporary restoration willbe required. Schedule the patient for anotherappointment. When all instrumentation is completeand infection is eliminated, gutta-percha is placed intothe canals with a sealer that acts as a cement. Then atemporary restoration can be placed.

After root canal treatment is completed, apermanent restoration is placed, usually at a laterappointment. At this time, the tooth may be evaluatedfor possible prosthodoiltics treatment to replace therestoration with an artificial crown.

During all appointments, use a rubber dam toisolate the tooth, prevent contamination of the rootcanal, and prevent the small endodontic instrumentsfrom going down the patient's throat.

ENDODONTIC MATERIALS

The main materials used in root canal therapy arevarious liquid antiseptics, paste, paper points,gutta-percha points, and sealers. The dentist uses theseto treat and fill a properly prepared root canal fromwhich the pulp has been removed.

Paper Points

Paper points are primarily used during thetreatment phase of endodontics to dry out root canals.They are highly absorbent, rolled sterile paper that arelong and narrow with a tapered point to fit into the rootcanal. Paper points are available in assorted sizes, fromcoarse to X-fine, depending on the size of the canal intowhich they are being inserted.

Root Canal Restorative Materials

Root canal restorative materials are used to fill thepreviously prepared root canals and complete the rootcanal or endodontic therapy. Root canal restorativematerials consist of tapered gutta-percha points in avariety of sizes and root canal sealers or cements. Agood root canal restorative material should beinsoluble in tissue fluids, opaque to the passage ofX-rays, easy to remove, nonirritating to periapicaltissues, nonabsorbent, and dimensionally stable afterits insertion into a root canal.

GUTTA-PERCHA. —Gutta-percha is used as atemporary restoration and as a root canal restorativematerial. Gutta-percha is the refined, coagulated,milky exudate of certain trees. It is pink or gray incolor, softens when heated, and is easily molded.When it is cool, it maintains its shape well.Gutta-percha points have been a choice for root canalrestorative materials for many years. The manyadvantages of the material are as follows:

High thermal expansion

Will not shrink unless used with a solvent

Radiopaque

Can be kept sterile in an antiseptic solution

Resistant to moisture and bacteriostatic

A poor heat conductor

The disadvantages of gutta-percha are as follows:

Shrinks when used with a solvent

Is not always easily inserted into the root canal

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Gutta-percha points are prepared for insertion by Endodontic Explorersdisinfecting them in sodium hypochlorite. They arethen air dried, condensed, compacted and inserted intothe root canal after the canal walls are coated withsealer.

TEMPORARY FILLINGS.—Temporary fillingis a temporary restorative material used to seal theaccess cavity in the tooth between appointments. Itmay be a commercially available material packaged ina tube, or an intermediate restorative material such asZOE.

ROOT CANAL SEALERS.—The root canalsealers most commonly used in dentistry are packagedin cement and paste form. The zinc oxide and eugenoltype is the cement most often used. The liquid eugenol,and a typical zinc oxide powder formula may containseveral ingredients as follows:

Zinc oxide-main ingredient

Resins-vegetable or mineral oil types

Anhydrous sodium borate

Bismuth subcarbonate or subnitrate

Besides the main ingredients, some formulascontain silver particles or barium sulfate, which addradiopaque (ability to stop radiant energy such asX-rays) qualities. These ingredients are mixed in muchthe same way as in zinc phosphate cement. Using aster i le glass s lab and noncorroding spatula,incorporate the powder into the liquid until a thick,creamy consistency is reached.

INSTRUMENTS AND ACCESSORIES

Endodontic instruments and accessories often areprepared in sterile packs or kits. A basic instrumentsetup can be established for endodontic procedures.The standardized setup can be used during each phaseof treatment and supplemented with items needed for aspecific phase of treatment. Items that make up arubber dam setup must be included since the rubberdam is essential to provide isolation and maintain asterile field. Figure 7-2 illustrates a typical instrumentendodontic tray setup. Small endodontic instrumentsand supplies are generally placed in a metalcompartmentalized box that can be sterilized andmaintained in an orderly fashion. Figure 7-3 identifiessuch an example and figure 7-4 list the contents. Avariety of accessory items, such as instruments, fillingmaterials, irrigation solutions, cements, andmedications used in the endodontic treatment must bereadily available during the procedure.

Endodontic explorers (fig. 7-5) have long, narrowworking ends. These explorers are angled from theirshank in such a way that they provide easy access to thepulp canal. They are used to locate canal openings andexplore the pulp chambers and canals.

Endodontic Cotton Forceps

These instruments resemble the cotton forceps.The major difference is that the endodontic cottonforceps are grooved to allow easy grasping andmanipulation of paper points and gutta-percha. Theyare also available in locking or nonlocking design.

Endodontic Excavators

These instruments are long, double-ended spoonexcavators designed for endodontic treatments. Theyallow the removal of coronal pulp tissue, caries, orcotton pellets that may be deep in the tooth's crown

Broaches

A root canal broach (fig. 7-6) is usually one of thefirst instruments used in the pulp canal duringendodontic treatment. Broaches are thin, flexible,usually tapered and pointed, smooth or with a series ofsharply pointed barbed projections curving backwardand obliquely. The identification symbol of barbedbroaches is an eight-pointed star formed by the barbs.

Smooth broaches can be used as explorers to getthe feel of the canal. A barbed broach is used primarilyfor the removal of intact pulp tissue from large canals.The broach is introduced slowly into the root canaluntil gentle contact with the canal walls is made. It isrotated 360 degrees in either a clockwise orcounterclockwise manner to entangle the pulpal tissuein the protruding barbs. It is then withdrawn directlyfrom the root canal. If successful, the entire pulp comeswith it. Because these instruments are fragile andprone to breakage, exercise great care in their use.There are several sizes: coarse, medium, fine, X-fine,XX-fine and XXX-fine. Discard each broach aftereach use.

Reamers

Root canal reamers (fig. 7-7) are used to enlargethe pulp canal after broaches have been used. Reamersmay be used with a reaming action (rotary cutting) or afiling action (scraping or pulling stroke). Reamers are

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Figure 7-2.—Typical endodontic instrument tray setup.

usually tapered and pointed, with spiral cutting edges.Since the cutting edges of reamers are farther apartthen those found on files, reamers are more flexiblethan files. This same distance between the cuttingedges causes reamers to cut slower than files. Reamerscan also be used to remove old, softened gutta-perchafilling, or as a paste carrier to place cement near theapex.

Reamers are available in many sizes beginningwith size 10 and continuing in intervals of 5 to size 60.Beginning with size 60, they are also available inintervals of 10 through size 140. The dentist may useseveral reamers in one operation, usually beginning

with a relatively small size, then the next larger sizeeach time the canal has been reamed to the desireddiameter.

Files

Root canal files normally are used after thebroaches and reamers. The root canal files look muchlike those of the reamers. However, the file threads orcutting edges are much finer and closer together. Filescome in two different types (H and K types) and aredifferent in terms of physical properties, such asflexibility, resistance to fracture in rotation, andmethod of manufacture. The designation of "K-type"

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Figure 7-3.—Typical enclodontic box kit with supplies.

or "H-type" is a generic classification based on a

manufacturing process and does not apply to any

single design or line of instruments.

Numerical size designations and color coding are

the same for both file types. Sizes begin with size 8 and

continue through size 140. Files come in different

lengths, including 19 mm, 21 mm, 25 mm, and 31 mm.

K-Type.—The K-type is tapered and pointed,with tight spiral cutting edges arranged so that thecutting occurs on either a pushing or pulling stroke.They are used to enlarge the root canal by a rotarycutting or abrasive action. When pulling theinstrument out of the tooth, the cutting edges scrapeagainst the wall, gouging and removing dentin in afiling action. When the instrument is turned in a

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Figure 7-4.—Items and inventory levels of endodontic box kits.

Figure 7-5.—Endodontic explorers.

clockwise, rotary action, the cutting edges scrape the

wall and widen the preparation in a reaming action.

K-type root canal files (fig. 7-8) are, size for size,

stiffer and stronger than comparable types of files. The

identification symbol for K-type files is a square.

H-Type.—The H-type are tapered and pointed,with spiral cutting edges arranged so that cuttingoccurs principally on the pulling stroke. These filesalso know as "Hedstrom" (fig. 7-9) are used to enlargethe root canal by either a cutting or an abrasive action.The series of intersecting cones forming the filebecome successively larger from the tip toward thehandle. The sharp blades of the H-type files cut morequickly than reamers or K-files. The H-type files arefrequently used for flaring of the canal from the apicalregion to the occlusal or incisal opening. Theidentification symbol for H-type files is a circle.

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Figure 7-6.—Root canal broach with enlarged view.

Figure 7-7.—Reamer with enlarged view.

Figure 7-8.—K-type file with enlarged view.

Figure 7-10.—Gates-Glidden drills.

flame-shaped shanks. As a rotary cutting instrument,they call be used with a slow-speed contra-angle andwith friction-grip straight handpieces. The number ofbands at the base of the drill indicates the size of thedrill. Their sizes are numbered 1-6. Size #1 is fragileand therefore rarely used to avoid the possibility ofbreaking off inside the canal.

Lentulo Spiral

The lentulo spiral (fig. 7-11) is designed totransport cement or paste to the finished root canalbefore the placement of the gutta-percha master cone.It is used with a latch-type handpiece and is small andflexible in design.

Endodontic Condensers

There are two types of endodontic condensers. Thefirst type is referred to as a plugger or verticalcondenser. The working end is contra-angled, andcylinder-shaped with a flat tip designed to condenseroot canal filling materials vertically into prepared rootcanals. The plugger shown in figure 7-12, hasserrations at 5-mm intervals to evaluate penetrationdepth.

Figure 7-9.—H-type file with enlarged view.

Gates-Glidden Drills

Gates-Glidden drills (fig. 7-10) are designed toenlarge the root canal. They are designed with long

Figure 7-11.—Lentulo spiral.

Figure 7-12.—Root canal plugger or vertical condenser.

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The second type of endodontic condenser is calleda spreader. The root canal spreader (fig. 7-13) has acontra-angled working end that tapers to a point(compared to the flat tip of a plugger). This instrumentis single ended. Spreaders are designed to condenseroot canal filling materials horizontally against thewall of the prepared root canal.

plugger. The finger spreader has a pointed end, thefinger plugger has a flat end.

Finger spreaders and finger pluggers have a handlelike a file and a smooth working end like a spreader or

Endodontic Measuring Gauges

are vital to the success of root canal therapy. Thedentist uses a measuring gauge to measure the workinglength of files, reamers, and broaches. Two styles ofmeasuring gauges are commonly used. The first type isshown in figure 7-14. The finger or thumb ruler is theother type used. The exact working distance can be seton the bar and is confirmed when the end of theinstrument reaches the metal plate. The example in fig.7-14 shows the working distance of a file set at 21 mm.

Precise measurements of the length of a root canal

Stops

Stops (fig. 7-15) are small, round or square piecesof rubber, plastic, or silicone placed on the files,reamers, or broaches to mark the length of the canal.This prevents injury to the apex of the root andperiapical tissues.

ANESTHESIA AND PAIN CONTROL

A local anesthetic must be administered by thedentist before endodontic therapy if the tooth is vital. If

Figure 7-13.—Root canal spreader.

Figure 7-14.—Measuring gauge.

Figure 7-15.—Stop attachments.

the tooth is hypersensitive, it may require injection ofadditional solution directly into the pulp. When a toothis nonvital, the use of local anesthetic solution is notmandatory. At subsequent visits, after the pulp hasbeen removed, local anesthesia may not be necessary.The dentist may give the patient a prescription formedication to control any anticipated postoperativediscomfort or infection.

ISOLATION

Endodontic therapy involving the removal of thepu lp and sea l ing the empty cana l r equ i re sdebridement, irrigation, and sterilization of the pulpchamber and canals as part of the procedure. Thesesteps of the procedure are necessary to ensure againstfuture infection by eliminating bacteria before thecanal is sealed. An absolutely dry field, free frombacteria-laden saliva is required to achieve suchsanitation of a root canal. Additionally, the rubber damprevents patients from swallowing or aspirating thevery small instruments used in endodontic treatment.This dry field is maintained best with a rubber damisolation. The rubber darn usually is prepared to exposeonly the tooth to be treated endodontically, therebyproviding isolation of the tooth with the rubber dam. Aradiolucent rubber dam frame made of plastic is

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commonly used and saves valuable time whenexposing radiographs. Metal rubber dam frames mustbe taken off while exposing radiographs. Remember arisk of contamination can occur while the frame is off.

OPENING THE PULP CHAMBER ANDCANALS

After the tooth is isolated, the dentist makes anopening through the crown of the tooth to gain accessto the pulp chamber and canal. The opening is madethrough the lingual surface on anterior teeth (fig. 7-16,A) and through the occlusal surface on posterior teeth(fig. 7-16, B). Friction-grip and latch-type burs ordiamond stones are used to create the endodonticopening. Sizes vary according to the preference of thedentist and the size of the chamber and canals of thetooth.

REMOVING THE PULP

After the endodontic opening is made, the dentistwill locate the root canals and remove the pulp.Anterior teeth usually have one root canal, but oftenlower incisors will have two canals. Posterior teethmay have up to four canals of different sizes.Anatomical variations exist among patients; therefore,additional canals may be found. A thin, straightexplorer can be used as a probe to locate canalopenings within the pulp chamber. The larger pulpcanals are easier to locate; whereas, smaller canals aresometimes difficult to locate.

Figure 7-16.—Access to pulp chamber and canal: A. Anteriorteeth; B. Posterior teeth.

Once the canals are located, the pulp tissue must beremoved. If the pulp tissue is still intact, the thin,flexible, barbed broach is used to remove it. Broachesare considered disposable and should be discardedafter one use, since they are subject to fracture afterrepeated sterilization. If the pulp tissue hasdisintegrated, it is simply removed when the canal iscleaned and filled.

IRRIGATION

After the root canals are accessed and the pulptissue is removed, the root canals are cleaned with anirrigating solution. Irrigation and evacuation areessential parts of endodontic treatment because theyassist in the removal of pupal remnants and tissuefluids. The irrigation solution also serves as a lubricantin the instrumentation and enlargement of the canalwalls.

The most frequently used solution for irrigation ofthe root canal is sodium hypochlorite or commonhousehold bleach. This solution is a solvent fornecrotic tissue, in effective disinfectant to destroybacteria in the canal, and acts as a bleaching agent.Sodium hypochlorite may be used full strength ordiluted with 1 to 2 parts water to reduce the chlorineodor.

A sterile, disposable, plastic Luer lock-typesyringe (5 cc to 10 cc sizes) with a disposable, blunt 20to 27 gauge needle is the comnon instrument used toinject the irrigating solution into the canals. The needlemay be bent at an angle to provide access to the canal.

The irrigating solution is injected slowly andgently into the canal to prevent the solution from beingforced into the periapical tissue. A small root canal fileor reamer can then be placed into the canal and rubbedagainst the pulp canal walls to produce a scrubbingeffect that loosens debris and bacteria. The solution isremoved with a suction tip on the oral evacuator. Anyremaining solution may be absorbed by placing sterilecotton pellets and paper point into the canal. There arenumerous times during endodontic treatment in whichyou will be required to provide thorough irrigation ofthe pulp chamber and canals. The following are themost common:

Before the use of intracanal instruments once theroot canal is accessed and the pulp tissue isremoved.

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Before the instrumentation of a previouslyopened pulp cavity to remove food particles andsaliva.

At intervals during instrumentation, often aftereach size file is used.

At the completion of canal instrumentation,before placement of medication.

When using root canal preparation type.

CANAL CLEANSING AND SHAPING

Canal cleansing and shaping is the progressiveelimination of organic and inorganic debris within theroot canal by mechanical instruments. As part of thecleansing process, the canals are enlarged and shapedwith endodontic files and reamers. Filing shapes thewalls of the root canal so that they are smooth withspecific size and shape.

The filing procedure begins by first establishingthe approximate or estimated length of the root canal.Accurately determining the length of the tooth is vitalto successful endodontic treatment. Failure todetermine an accurate length may lead to apicalperforation and overextension, with increasedpostoperative pain or incomplete instrumentation andunderfilling.

The estimated length is determined from anaccurate, preoperative periapical radiograph of thetooth being treated. Multirooted teeth may requireradiographs from various horizontal angulations todetermine the exact number and alignment of eachroot. The length of the tooth is measured using eitheran endodont ic millimeter ruler (fig. 7-17) or a file heldnear the radiograph from a reference point on thecrown portion of the tooth to the apex. Good referencepoints are the incisal edges of anterior teeth and cuspson posterior teeth. Files are measured on a millimeterruler and marked accordingly with the placement ofrubber stops. The estimated working length is recordedin the patient record for future reference andmodification. If necessary, a more accurate length isestablished as the filing process continues. Theworking length is verified by exposing and measuringa periapical radiograph with a reamer or tile in thecanal. Once the tooth length is established, you will usean endodont ic gauge to adjust the position of therubber stops on the appropriate sizes of reamers andthe files the dentist selects. It is important that therubber stops be placed at a right angle to the long axisof the instrument and not an oblique angle. When thefile is inserted into the root canal, the rubber stop

touches the reference point on the crown when the tipof the file is at the apex of the root. With the stops in

lengths.

place, arrange the reamers and files in order of theiruse. As the filing progresses, the file sizes areincreased to enlarge the size of the canal. When teethwith more than one canal are filed, it is essential thateach canal be filed to a predetermined length.Occasionally, an electronic apex locator may be usedto help verify the working length. Each canal can befiled to different diameters, as well as, different

During the filing, the root canal is irrigated withsolution to keep the dentin shavings from the canalwalls from clogging the cutting edges of the file. Afterthe filing is complete, the canal is thoroughly flushedsimultaneously with irrigating solution and suction.The canal is dried with paper points held in lockingforceps and inserted into the canal to absorb thesolution. This is repeated with several paper pointsuntil the paper points are completely dry whenwithdrawn.

MEDICATIONS

After the root canal is dried with paper points,medications are occasionally placed in the canalbetween appointments to aid in the control ofmicrobial activity within the tooth. A small cottonpellet is moistened with medication and blotted drywith a cotton roll or gauze. The small dry medicatedcotton pellet is placed on the floor of the pulp chamber(fig. 7-18) over the opening on the canal and coveredwith a larger, dry cotton pellet. More often, only a drycotton pellet with no medication is placed, or a paste ofcalcium hydroxide is placed into the canals before thedry cotton pellet is placed. A temporary filling must beplaced over the larger cotton pellet to preventcontaminating the root canal with saliva and food

Figure 7-17.—Estimated working distance using anendodontic millimeter ruler.

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Figure 7-18.—Placement of dry medicated cotton pellet.

debris between appointments. Amalgam, zinc oxideand eugenol (ZOE), or. a commercially ready-madecement may be used for this purpose.

ROOT CANAL FILLING

If a medicated cotton pellet or temporary fillingmaterials have been placed, these items must beremoved and the canals irrigated and dried with paperpoints before proceeding to fill the root canal.Gutta-percha points or cones, available in various sizesare the most common filling material for a preparedroot canal.

An appropriate sized gutta-percha point is selectedand may be shortened slightly to blunt the tip. Thepoint is placed into the canal to a depth where the pointseems snug when gently tugged. This point is referredto as the master cone. A radiograph with either theapical tile, or master cone point in place is exposed toverify the proper length. The tip of the master coneshould provide an adequate seal of the apical foreman.This radiograph often is referred to as a master coneradiograph. If adjustments are needed to achieve theproper length of the master cone, additionalradiographs may be exposed to verify the propellength. A properly titted master cone also allows spacebetween the point and the walls of the prepared canal.Before the master cone is removed, a slight mark isplaced on the point at the line where it is even with theopening of the tooth by squeezing the cotton forceps onthe gutta-percha. The master cone is now ready forcementing.

Mix the cement according to the manufacturer'sinstructions. The master cone is removed and a paperpoint is placed in the canal to absorb moisture that mayaccumulate. The consistency of the cement should becreamy but quite heavy. The dentist may choose to dip

a lentulo spiral or reamer into the cement mix, insert itapproximately halfway into the canal, and rotate it todistribute the cement onto the dry walls of the canal.With the master cone placed into the cotton pliers, theapical third of the cone is coated with cement. The coneis then inserted into the canal and seated to the markmade on the cone.

The space between the cemented master cone andthe walls of either the root canal or pulp chamber istilled with additional gutta-percha points (accessorycones) of smaller diameter alongside the master cone.Filling the canal with additional gutta-percha points isdone by inserting an endodontic spreader beside themaster cone and applying lateral pressure to condensethe cone against the walls of the canal. As the spreaderis removed from the canal, a smaller additionalgutta-percha point in inserted in the space. The processof lateral condensation and addition of gutta-perchapoints continues until the canal is filled completely.Figure 7-19 illustrates the steps in filling a root canalwith the master and accessory cones.

The excess length of gutta-percha is removed witha heated instrument. An endodontic plugger, alsoknown as a vertical condenser, is used to condense thestill warm gutta-percha vertically toward the apex ofthe tooth. More gutta-percha can be added if needed,and the process of vertical condensation continueduntil the canal is filled completely.

When a tooth has more than one root canal, eachcanal is filled individually and each requires a properlyfitted gutta-percha point sealing in it. A perfect sealingof the apical foramen in the roots of the teeth isessential to eliminate irritation of periapical tissue.Any excess gutta-percha and cement are removed fromthe pulp chamber and the chamber then sealed with atemporary restoration.

Amalgam or composite materials may be placed tofill the carnal opening and restore the tooth permanently(fig. 7-20). Teeth successfully treated endodonticallymay also be restored with prosthodontics treatment,such as onlays and artificial crowns. As a rule,follow-up appointments are scheduled periodically forradiographs of the restored tooth. The dentist uses thepost-treatment radiograph as an aid to determine theelimination of infection and progress of boneregeneration.

STEPS IN APICOECTOMY (ROOT ENDRESECTION)

The apicoectomy (root end resection) requiresteamwork between the dentist and his/her assistants.

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Figure 7-19.—Steps in filling a root canal with master and accessory cones.

Figure 7-20.—Permanent restoration in place on completedroot canal.

Along with the apicoectomy, the dentist usuallyperforms a periapical curettage and may place aretrograde filling. After the patient has been drapedand anesthetized, the dentist makes a surgical incisionon the facial aspect of the alveolar ridge and amucoperiosteal flap is elevated to expose the apex ofthe tooth to be treated. The assistant aids in retractionof the mucoperiosteal flap with the periosteal elevatorand provides suction. This reveals the cortical bone ofthe alveolus covering the apex of the tooth. The dentistthen uses a handpiece and surgical bur to remove thecortical plate covering the apex of the tooth. Once theroot is exposed, the dentist uses the bur to remove theapex as shown in figure 7-21. The assistant irrigateswith a saline solution and aspirates as needed. Thedentist uses a curette to curettage the surrounding

Figure 7-21.—Removing apex of tooth.

periapical tissue, thus removing infectious materialfrom around the root tip. Figure 7-22 illustrates thecurettage procedure. If access to the canal is obstructedfrom the occlusal or lingual aspect, debridement andfilling can now be done from the apex.

If indicated, a retrograde filling may be performedto seal the apical end of the root canal by placing a

Figure 7-22.—Apical curettage procedure.

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restoration in the root apex. The dentist may use an hemostatic agents are carefully removed to avoidultrasonic or a high-speed handpiece with a bur to dropping scraps or cement into the incision. The site

prepare the blunted apex for the filling. When the may be irrigated and aspirated again.

preparation is complete, the surgical site is irrigatedcarefully with saline solution and aspirated until it is

A radiograph is exposed to determine the absence

dried thoroughly. Hemostatic agents such as bovineof any filling particles in the tissue at the surgical site.

collagen or ferric sulfate may be placed to controlWhen it is determined that the filling is satisfactory andthat all particles of the filling material are removed,

bleeding and to catch scraps during the placement and sutures are placed to close the incision. The surgicalcondensation of the root end filling material. portion of the apicoectomy is done quickly. The longerIntermediate restorative material such as ZOE, or the patient is subjected to a surgical procedure, thesuper EBA cement (ethoxybenzoic acid) is mixed and more likely it is that there will be swelling andplaced into the recessed preparation of the root apex. discomfort. Follow-up appointments usually areThe retrograde filling is condensed and smoothed even scheduled periodically for radiographs of the restoredwith the tip of the amputated root surface. The tooth.

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CHAPTER 8

PROSTHODONTIC ASSISTANCE

To be an effective prosthodontic assistant, youneed to be familiar with the following generalinformation and basic skills. Your duties will includesome of the following:

Assisting the dentist in prosthodontic procedures

Setting up prosthodontic instrument trays

Preparing material for prostliodontic procedures

Making diagnostic impressions and casts

Trimming dental casts

Fabricating mouth and bite guards and customtrays

Performing simple acrylic repairs

A prosthodontist is a dentist with specializedtraining in replacing missing teeth; however, manygeneral dentists in your clinic will be able to provideprosthodontic care. Your prostliodontic assistingduties are very similar to those in other specialties. Theprimary differences are the types of treatment thedentist performs, the material you mix or manipulate,the instruments the dentist uses, and the coordinationrequired with the dental laboratory personnel.

Prosthodontic dentistry deals with the substitutionor replacement of oral structures. Prosthodonticdentistry can include anything from replacing onemissing tooth to constructing a complex—designeddevice to replace structures of the face such as eyes,ears, or a cleft palate. Prosthodontic treatment isconcerned primarily with replacing missing teeth withsome type of artificial substitute. Substitutes fornatural teeth are called prosthodontic prostheses.Prosthodontic prostheses are either fixed permanentlyinto the patient's mouth or removable.

TYPES OF FIXED PROSTHETICS

A fixed prosthesis is any variety of replacementsfor a missing tooth or part of a tooth that a dentistcements in place and the patient cannot remove.Restorations, such as inlays, onlays, crowns, and fixedpartial dentures fall into this category. A fixedprosthesis may be constructed entirely from a castmetal alloy, acrylic resin, or porcelain. Frequently, afixed prosthesis is made of a combination of these

materials. For example, a complete crown may have ametal substructure and a porcelain veneer (facing).

INLAY

An inlay is a dental restoration that fits into aprepared cavity, and is held there by its precision fitand a cementing medium. Inlays are, for the most part,surrounded by intact tooth structures. For this reason,they are often called intracoronal restorations. Thevarious forms of inlays are used primarily to restoreIndividual tooth contours and function. In the majorityof cases, an inlay is not a suitable anchor casting(retainer) for a fixed partial denture. Inlays are usuallycast in medium hard gold, but can be made of othermaterials (porcelain, resin).

There are five classes of inlays (class I, II, III, IV,and V) based on the location of the surfaces beingrestored. A more specific way of naming an inlay is tocite the tooth surfaces it restores; for example, MO(mesio-occlusal) inlay, or a MOD (mesio-occlusal-distal) inlay as shown in figure 8-1.

ONLAYS

Onlays are cast gold, resin, or porcelainrestorations that ordinarily cover the mesial, occlusal,and distal surfaces (MOD) of posterior teeth. Onlaysdiffer from inlays in that an onlay covers the entireocclusal surface of a tooth to include the cusps. Anonlay is the smallest of the fixed prosthetic restorations

Figure 8-1.—MOD inlay.

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classified as an extracoronal. An intracoronalreplacement like an inlay fits into a tooth. Anextracoronal restoration fits around what remains of atooth.

ARTIFICIAL CROWNS

An artificial crown is a fixed prosthetic restorationthat covers more than half of the coronal portions of thetooth. There are several types of crowns. They may bemade of gold, porcelain, acrylic, or a combination ofthese materials. Along with onlays, which areclassified as extracoronal restorations, are the variouskinds of crowns that make up the balance of theextracoronal category.

Partial Crown

A partial crown is a cast restoration made entirelyfrom metal and covers more than half but not all of thetooth's clinical crown. A partial crown is namedaccording to the fractional amount of the clinicalcrown it covers. Examples are the half, three-quarters(see fig. 8-2(A)), four-fifths, and seven-eighths crowns(see fig. 8-2 (B)). In most instances, the facial surfaceof the tooth is not disturbed for esthetic reasons.

Complete Crown

A complete crown covers the entire anatomy of atooth’s clinical crown. There are several types ofcomplete crowns. A complete metal crown isconstructed entirely of a noncorrosive metal, such asgold (see fig. 8-2(C)). A complete veneered crownconsists of complete coronal coverage of the tooth witha metal substructure overlaid with porcelain or resinfor esthetic effect (see fig. 8-2(D)). A complete crownconstructed of cast metal with a fused porcelain(ceramic) veneer is commonly called a PFM(porcelain-fused-to-metal) crown.

A post crown is a complete crown of any kind(complete metal, veneer), supported by a metalextension (post) into a tooth's root canal. Because thepulp is removed from teeth that are endodonticallytreated, the teeth eventually become brittle and areprone to fracture. In many instances, the teeth are alsodestroyed by caries or previous restorations and verylittle clinical crown is left. Often, only the root portionis left to retain the crown. To maintain anendodontically treated tooth as an abutment (anchor)capable of supporting and retaining a crown, it iscommon practice to cement a post about two-thirds ofthe way into a root canal. To do this, a gold casting

Figure 8-2.—Types of artificial crowns.

called a post and core, must be constructed. The part ofthe post that protrudes from the root canal is called thecore. The core, combined with the remains of thecoronal part of the tooth, is built to resemble acomplete crown preparation. After the post and coreare cemented into the root, a complete crown isfabricated on top of this foundation (fig. 8-3). Post andcore castings are most often associated withendodontically treated anterior teeth, but they may alsobe used on posterior teeth as well (fig. 8-4).

FIXED PARTIAL DENTURE

A fixed partial denture (FPD) (fig. 8-5) is arestoration designed to replace more than one missingnatural tooth. In contrast to a removable partialdenture, the dentist attaches an FPD to natural teeth(abutments) or roots by cementation. An FPD consistsof two types of units: retainers and pontics. The unitcastings are joined together by connectors. The overallsize of the FPD is measured in units. Each pontic orretainer counts as one unit. For example, an FPD withthree retainers and two pontics has a total of five units.The units of an FPD may be made entirely from metal,combination of metal or resin, or from a combinationof metal and porcelain. Next, we will discuss theretainers, pontics, connectors, and abutments thatmake up the FPD (fig. 8-5).

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Figure 8-3.—Post and crown.

Figure 8-4.—Post and core for anterior and posterior teeth.

from the retainer casting. A pontic occupies the space

Figure 8-5.—Components of a typical FPD. formerly filled by the crown of a natural tooth.

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Retainers

Part of the FPD will have metal castings, calledretainers. They are made to fit onto what the dentisthas cut away on the abutment teeth. Retainers alsosecure and support the FPD's artificial tooth or teeth.The most commonly used retainers are PFMs,complete metal crowns, partial crowns, and onlays.

Pontics

A pontic is an artificial tooth that is suspended

Connectors

A pontic is attached to a retainer by a connector.Connectors can be rigid or nonrigid. Nonrigidconnectors take the form of male- and female-lockingarrangements. Rigid connectors are classified as eithercast or soldered.

Abutments

The teeth that support and hold the retainer arecalled abutments. It is almost mandatory that an FPDbe supported by an abutment at both ends. Thisrequirement is waived in special situations. When apontic is suspended from only one retainer, it iscantilevered.

FIXED SPLINTS

A number of teth can share a load being placed onone of them. This helps prolong the life of loose teethor those that have lost supporting bone. Stabilizing amobile tooth or teeth is called splinting. Whenstabilizing adjacent teeth with connected castings thatare cemented in the mouth, the prosthesis becomes aform of fixed splinting. Such splints are made in thesame fashion as an FPD.

RESIN-BONDED FIXED PARTIALDENTURES (MARYLAND BRIDGE)

This type of fixed prosthesis is made of a singlepontic and thin metal retainers located both proximallyand lingually on the abutment teeth. The retainers arespecially designed metal-extensions (wings). The FPDis retained by a resin bond between the acid etchedabutment teeth and the metal surface of the retainer. Amissing left central incisor is illustrated in A of figure8-6. A fabricated Maryland bridge is illustrated in B offigure 8-6. The bridge in place from the lingual aspectis illustrated in C of figure 8-6. A posteriorresin-bonded FPD is shown in figure 8-7.

INTERIM FIXED PARTIAL DENTURE

This is a rigid, temporary restoration that replacesmissing teeth and is generally made from a self-cuttingresin. Its purpose is to protect cut tooth surfaces andhold the abutment teeth in position while the definitiveFPD is being fabricated in the dental laboratory.

Figure 8-6.—Anterior resin-bonded FPD (Maryland bridge).

Figure 8-7.—Posterior resin-bonded FPD (Maryland bridge).

TYPES OF REMOVABLE PROSTHETICPROSTHESES

The three basic types of removable prostheticprostheses are complete dentures, removable partialdentures, and overdentures. There are variations ofeach of these types.

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COMPLETE DENTURES

A complete denture (CD) is a type of removableprosthesis designed to replace all of the natural teeth inan arch and associated structures of the maxilla ormandible (fig. 8-8). However, a CD denture does notusually replace third molars.

The CD consists of an acrylic base and porcelain oracrylic artificial teeth. The base is designed to fit overthe alveolar ridge, and is composed of the saddle andgingival area. Sometimes, patients need a set of CDs;one for each arch. If a CD is constructed for insertionimmediately following the surgical removal of’ allremaining teeth, it is considered an immediatecomplete denture. Before a conventional prosthesis isfabricated, the extraction sites must be completelyhealed. Therefore, immediate dentures are oftenconsidered temporary or interim prostheses. Theimmediate denture also functions as a psychologicalaid to the patient, who will never have to be completelywithout teeth. Immediate dentures usually requirerelines 3 to 12 months after initial insertion. This isbecause of the dramatic reduction in the ridge sizeduring the healing process.

Figure 8-8.—Maxillary and mandiburlar complete dentures(CDs).

REMOVABLE PARTIAL DENTURES

A removable partial denture (RPD) is a type ofremovable prosthesis designed to replace one or moremissing natural teeth (but not all), gingival tissue, andassociated parts of the maxilla or mandible. Figure 8-9illustrates maxillary and mandibular RPDs.

There are several RPD types, based on thematerials used to construct the prosthesis. One type isa cast metal RPD. This prosthesis may have a castmetal framework with denture plastic and artificialteeth made of resin, ceramic, or metal attached. A castmetal RPD may also be constructed of all metal inwhich the entire RPD (frame, denture base, and teeth)are all made from cast metal. The dental laboratorywill use a nickel chrome-alloy (ticonium metal) forRPD framework castings.

Another type of RPD is the resin RPD madecompletely of acrylic resin. Sometimes, wrought wireclasps are added to the plastic body of a resin RPD tohelp retain it in the mouth. The resin RPD is oftenconsidered an interim RPD and is intended to betemporary in nature. Resin RPDs are used to replace ametal RPD that is broken, no longer fits, or may beprescribed to patients who lose any anterior teeth froman accident. Resin RPDs are a less expensive, and atemporary substitute for replacing missing naturalteeth.

If a partial denture is constructed for insertionimmediately following the surgical removal of naturalteeth, it is called an immediate partial denture. Theseprostheses are often considered temporary or interimprostheses because they are used for a period of time inbetween events. Once the extraction sites are

Figure 8-9.—Maxillary and mandibular RPDs.

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well-healed, a conventional RPD is constructed.In-mediate partial dentures are usually fabricatedcompletely of a resin base and denture teeth.

OVERDENTURES

These prostheses include complete, partial, andimmediate overdentures. A complete overdenturereplaces the entire dentition and is constructed forinsertion over one or more remaining prepared teeth,roots, or dental implants. A partial overdenturereplaces the partially missing dentition and isconstructed for insertion over one or more remainingprepared teeth or roots. If the overdenture isconstructed for insertion immediately following thesurgical removal of natural teeth, leaving no strategicteeth to support the denture, the prosthesis isconsidered an immediate prosthesis.

PROSTHODONTIC MATERIALS

Many dental materials are unique to prosthodonticprocedures. The improper use of any of these materialscould cause a delay in the treatment and aninconvenience to the patient. You should be familiarwith the use, handling, reaction time, and storingprocedures for these materials. This knowledge isnecessary for your successful performance as aprosthodontic assistant.

DENTAL ALLOYS

Although you do not make dental prostheses as abasic dental assistant, you must know enough about thematerials used in their construction to documentproperly the treatment patients receive. When apatient’s prosthesis is given to a dental lab for repair orchange, they need to know its history to do the workproperly, or a tragic result may follow. You shoulddocument al I laboratory requests and patient dentalrecords with information, such as alloy type used,solder type, and tooth shade if applicable.

Dental alloys can be classified as precious,semiprecious, and nonprecious. For the purpose oftraining and clarification, we will classify them asnoble metal or base metal alloys.

Noble Metal Alloys

Noble metals resist oxidation and corrosion. Thefour noble metals used primarily in dentistry are silver,platinum, palladium, and gold. Gold is very useful fordental put-poses. Although too soft for use alone, it can

be combined with other metals in varying proportionsto produce alloys of almost any desired properties.Other noble metals are used in most dental labs tofabricate crowns and FPDs because of the high cost ofgold.

Base Metal Alloys

Since base metal alloys do not contain noblemetals, they are much stiffer and harder. Thus, they areuseful for constructing RPDs and certain types ofFPDs.

IMPRESSION MATERIALS

Many types of impression materials are used in thedental clinic. However, no one material fulfills allrequirements for making a perfect negativereproduction of the oral structures. The dentist willdetermine which material will best meet therequirements for each case. The two commonly usedimpression materials are alginate hydrocolloids andsynthetic rubbers.

Alginate Hydrocolloids

Hydrocolloids that change state because ofthe rmal changes a re known as revers ib lehydrocolloids because the process can be changedback and forth by altering the temperature. Those thatare altered through a chemical change are known asirreversible hydrocolloids. Once the chemical changehas taken place, it cannot be reversed or turned back tothe previous state.

Irreversible hydrocolloids, more commonlyknown as alginates, were developed from seaweedduring World War II. Alginate impression material haslargely replaced the reversible type for impressions.The advantages of alginate material are that it is easy toprepare and handle, it does not require excessequipment and advanced preparation, it is comfortablefor the patient, and it is inexpensive. Alginate is usedin making preliminary impressions for all study castsand most final impressions for RPD working casts.

According to the American Dental Association(ADA) specifications, alginate materials are dividedinto two types based on gelling time:

Type I—Fast set material, must gel in 1 to 2minutes.

Type II—Regular set material, must gel in 2 to4.5 minutes after the beginning of the mix.

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Also, under ADA specification, the manufactureris required to include detailed instructions for use. Thedental assistant should read and follow these directionscarefully.

Synthetic Rubber Materials

Rubber impression materials are supplied aspastes in collapsible metal tubes that require mixing.One tube contains the base, while the other contains anaccelerator or a catalyst. When mixed in appropriateamounts, the mixture hardens to a synthetic rubber.Other types of materials come in the form ofdouble-barreled injector cartridges that do not requiremixing.

CONSISTENCY TYPES.—Rubber impressionmaterials can be used for almost any impression. Theycome in three consistencies and are discussed in theparagraphs that follow.

Light Bodied. —Light bodied impressionmaterials are injected with a syringe onto preparationsfor inlays, crowns, and FPDs. It is also used as a"wash" impression for full dentures, relinings, andRPDs. Its high degree of flow registers the fine detail.

Regular Bodied.—Regular bodied impressionmaterials are used in an impression tray for inlays,crowns, and FPDs.

Heavy Bodied. —Heavy bodied impressionmaterials are used in a tray to force light bodiedimpression material onto the cavity preparation or witha copper band for impressions of single teeth.

MATERIAL TYPES.—Rubber impressionmaterials can be grouped into three types depending ontheir composition: polysulfides, silicones, andpolyetliers.

Polysulficles. —The polysulfides (rubber base)can be identified by the usually dark color of one of thetwo pastes and their resulting opaque mix and sulfursmell. If the materials are improperly mixed, theimpression will have streaks in it, thereby affectingdimensional stability. Mixing time is between 45 and60 seconds with a 5-minute working time. Theimpression must not begin setting before placement inthe mouth. If the 5-minute working time is exceeded,the resulting impression will have inadequateexpansion, producing a smaller cast. The impressionmust set completely before removal from the mouthand poured no later than 1 hour after removal.

Silicones. —Silicone (vinyl polysiloxanes)materials are generally lighter in color, translucent

when set, and have a slight odor. Silicone types comein the form of a heavy putty, light, regular, and heavybodied viscosities. The silicone material is used with astock tray to make up the bulk of the impression and‘minimize distortion. Manufacturers have been able tocontrol shrinkage resulting in impressions with greateraccuracy when compared to all other rubber products.Impressions made from silicone do not have to bepoured immediately. The material will remainaccurate for several days so they can be repoured asnecessary.

Polyethers.—PoIyetliers have lighter colors thanpolysulfides, but are darker than silicones. Theworking and setting times are much shorter than theother two rubber impression materials. Polyether isjust as good to use as polysulfides to control shrinkage.Unlike polysulfide, polyether will absorb water. Thistype of impression material is very stiff, making itdifficult to remove from the mouth and a cast. Thedentist must take care when removing the tray with thematerial from the mouth, because the polyether tearseasily in thin areas like the subgingival sulcus. For bestresults, use this material with a custom tray.

GYPSUM PRODUCTS

Gypsum products are supplied in powder form.When mixed with water in the correct proportions, apaste forms that will eventually harden. This settingprocess takes place over several minutes, during whichtime the mixture is soft and pliable, and can be formedinto the desired shape. During the setting process,gypsum gives off heat, which is characteristic of all itsproducts. Each material in the gypsum group iscarefully compounded to give it the particularcombination of physical properties needed for aparticular work order. Dental plaster, stone, and diestone are the most frequently used gypsum products.

Dental Plaster

that the plaster must set within a definite time limit.

Plasters made for dental use are speciallyprocessed to provide high purity and suitable workingproperties. One of the most important requirements is

Plaster has many uses. It can be used to form casts,construct matrices, and attach mount casts to anarticulator. The initial setting time for most dentalplaster is from 7 to 13 minutes. The final set iscompleted within approximately 45 minutes.

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Dental Stone

Compared to plaster, dental stone requires lesswater in mixing and sets more slowly. When it is set, itis harder, denser, and has a higher crushing strength.These differences make stone the choice to use overdental plaster when using it as a master cast forcomplete dentures and partial denture construction.Stone is more resistant to scratching and damage andcan withstand more pressure in acrylic processing.Stone has many uses, including pouring, mountingcasts, and flasking dentures for processing. The initialsetting time of a typical stone mixture varies from 8 to15 minutes. The final set occurs within approximately45 minutes.

Die Stone

Historically, die stone was only used for makingthe first pour of a working cast for fixed prosthodontics.Improved die stone now is being used for workingcasts in removable prosthodontics.

DENTAL WAXES

Dental waxes are important in the construction ofdental prosthetic appliances. The waxes are suppliedin different types, with each designed for specificpurposes. Next we describe the waxes with which achairside prosthetic technician needs to be familiar andbe able to use.

Baseplate Wax

Baseplate wax is used to create a spacer over thecast before custom trays can be made. Another use isas a block-out wax for undercuts on casts. It isavailable in sheet and ribbon form and is pink in color.

Bite Registration Wax

Bite registration wax is a metal-impregnated waxin sheet form. It is used to record the occlusalrelationships between a patient's opposing arches andto later transfer this relationship to the cast forarticulation. Often without this record, it is impossiblefor the dentist or the laboratory technician to properlyocclude the patient's cast.

Indicator Wax

Indicator wax is usually green in color and iscoated with a water soluble adhesive on one side. It is

used for registering occlusal contacts on natural teeth,individual restorations, FPDs, RPDs, and CDs. It issometimes used by the dentist to evaluate high spots onrestorations.

Sticky Wax

Sticky wax is made of beeswax, paraffin, andresin. Its colors are orange and the darker shades ofblue, red, and violet. The resin gives the wax itsadhesiveness and hardness. An important requirementof sticky wax is that it must break under pressure ratherthan bend or distort. This property makes it useful forholding the parts of a broken denture together so that itcan be repaired.

Utility Wax

Utility wax is a red or colorless wax that comes inrope form. It is extremely pliable and tacky at roomtemperature, making it usable without heating. Its mainuse is in beading (curbing) impressions before boxingand pouring. It can also be used on the impressions traysto avoid the flow of impression material to the back ofthe throat and to avoid injury to the soft tissue.

ACRYLIC RESINS

There are a number of acrylic resins that you willuse and need to be familiar with in prosthetic assisting.Polymerization is the term used to describe theprocessing or curing of acrylic resins. Acrylic resinscan be classified by its method of curing. Some of themore common acrylic resins include the heat-cured,self-cured, and light-activated types. When handlingacrylic resins, you should be sure to read themanufacturer's instructions and safety precautionsbefore using.

Methyl Methacrylate

Methyl methacrylate is the most widely usedsynthetic resin used in dentistry. The resin is usuallysupplied in a fine powder (polymer) and liquid(monomer). They are mixed to form a gel or dough andprocessed into a rigid solid.

Clear Acrylic

Clear heat-cured acrylic resin is used to constructnight guards and surgical templates. As a surgicaltemplate (band-aid) it is used after extraction ofremaining teeth to show the possible interferencesbetween the alveolar bone and the immediate denture.

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Crown and Bridge Resin

These tooth-shaded acrylic resins are used in fixedprosthodontics to make temporary and permanentrestorations. The self-curing type is used as an interimrestoration while the permanent one is beingfabricated. This resin is normally used with a vacuumor pressure-formed matrix to sculpt the contours of theinterim crown or bridge.

Orthodontic Resin

Self-curing orthodontic resin is used to fabricatenightguards and orthodontic retainers. It is normallysupplied in the clear and pink types and can be usedwith several tinted liquids to produce different shades.

Repair Resins

These resins are used to fabricate interim RPDsand to repair any acrylic prosthesis. They are normallyonly stocked by the dental clinic in self-curing pinkand light-pink fibered shades.

oral tissues, head, and neck. Custom fluoride trays alsoare made out of this material for prescribed hometreatment with fluoride gels.

Separating Media

Separating media prevents one material frombonding to another material. The medium coats thecast and seals off the pores so acrylic resins can now befabricated on a dental cast and removed.

One type of separating media is tinfoil substitutethat when used, forms a film on the cast. To use, paintit on the cast with a soft bristle brush. The film isfragile and can easily be scuffed off. If this occurs,remove the entire film and repaint. Place the acrylicresin to the cast within 1 hour of painting the film onthe cast to avoid deterioration. Do not allow gypsumparticles to contaminate the bottle of tinfoil substitutewhen applying to a cast. Many other commerciallyprepared separators are available to prevent bonding.

Tray AdhesiveTray Acrylic

Self-curing tray acrylic is used to makecustomized impression trays. Tray acrylic is usuallylight blue or white in color. You can lengthen theworking time of this material by submersing the doughin cold water before it is ready to use.

OTHER PROSTHODONTICMATERIALS

Along with the prosthodontic materials previouslyexplained in the above categories, you need to becomefamilar with other miscellaneous materials such asalcohols, mouthguard materials, separating media,tray adhesive, and treatment liners.

Alcohols

Isopropyl, methanol, and denatured ethanol areexamples of fuels used in an alcohol torch for softeningplastic or melting wax. Of the three, denatured ethanolis preferred since it is safer to use and burns cleaner.

Mouthguard Materials

Mouthguards are made from polyvinyl materials.This thermoplastic resin is molded over a cast bymeans of a vacuum-forming machine. The use ofmouth protectors in sports is to reduce injuries to the

Custom impression trays are coated with thisadhesive before they are filled with rubber impressionmaterial. This ensures that the impression materialstays in the tray when it is removed from the mouth.Tray adhesive in spray form is also available for usewith alginate impression materials and stockimpression trays.

Treatment Liners

Treatment liners, also know as tissue conditioners,allow oral tisses to recover, improving tone andhealth, before making a new denture or reling anexisting one. The dentist changes the tissueconditioner at 3- to 4-day intervals since liners stiffenrapidly.

BASIC PROSTHODONTlCEQUIPMENT

The prosthodontic equipment that you will usewill be located in the dental laboratory and theprosthodontic DTR. Only the basic equipment ismentioned. Never operate or use any type ofequipment without first reading the manufacturer'sinstructions on use, safety precautions, andmaintenance.

8-9

ALCOHOL TORCH

The alcohol torch (fig. 8-10) is used for smoothingwax surfaces, setting teeth, and waxing. It is also usedwith a variety of tasks that require an accurate,controlled pointed flame. It draws fuel through a wickfrom a reservoir near the top of the torch. Periodicallytrim all irregular or burned areas of the wick and checkthe nozzle tip to ensure that it is free from obstructions.

CAUTION

Never overfill the fuel reservoir or attemptto fill it with the flame lit.

Before using an alcohol torch, you should checkthe fuel level. Many different types of fuels can beused with an alcohol torch. Isopropyl alcohol in asolution containing about 70-percent alcohol and30-percent distilled water by volume produces a flameof very poor quality. Further, 100 percent isopropylalcohol tends to smoke badly while burning, whichmakes it somewhat undesirable as torch fuel. The bestchoice fuel for the alcohol torch is denatured alcohol(ethenol), which produces a clear blue flame.However, care with the accountability of denaturedalcohol must be taken when used and distributed.Rubbing alcohol is unsuitable as a fuel.

Note: Methyl alcohol is highly poisonous if takeninternally.

Do not leave the torch unattended when lit.Extinguish the torch when not in use by covering thewick with the nozzle holder assembly.

Figure 8-10.—Alcohol torch.

ARTICULATOR

The articulator (fig. 8-11) is used to reproduce thepatient’s jaw movements. The dental cast made fromimpressions are mounted onto the articulator. Thisallows the dentist and the laboratory technician torecreate the normal movement of the patient’s jawduring the fabrication of the prosthesis. There areseveral types of articulators. The type of articulatorused depends upon the type of prosthesis beingfabricated.

BENCH LATHE

The bench lathe (fig. 8-12) is used during grinding,finishing, and polishing procedures. Always wearprotective glasses or goggles when working with thebench lathe. Ensure that all chucks and attachmentsare securely mounted before starting the lathe.

WARNING

Never leave an unattended lathe running,or attempt to stop the lathe by grasping theattachment with your hands.

Figure 8-11.—Articulator.

Figure 8-12.—Bench lathe.

8-10

The lathe is used with rotary instruments (burs,stones, arbor bands, and ragwheels, etc.). An adapterand/or chuck is required to attach these instruments tothe lathe.

BUNSEN BURNER

The Bunsen burner (fig. 8-13) heats wax-carvinginstruments, waxes, and modeling compound. Itrequires a balanced air and gas mixture to produce aclean blue flame. It is attached to a gas valve with anon-collapsible hose.

Inspect the unit and hose daily for looseconnections and defects. Have the hose replaced whenit shows signs of wear. When wax or similar materialdrops into the burner, the burner assembly detacheseasily for boiling out and cleaning.

WARNING

Never leave an unattended burner lit orreach over an open flame, because theflame is almost invisible and can causeserious harm.

CAST TRIMMER

The cast trimmer (fig. 8-14) is used to trim andcontour casts. A cast should present a neat, attractiveappearance. This electrically operated machine has a10-inch abrasive wheel, a small work table, and awater-dispensing mechanism to keep the abrasivewheel rinsed clean and clog free.

Before using the trimmer, ensure the water supplyis on. Allow the water to run for at least 1 minute after

Figure 8-13.—Bunsen burner.

Figure 8-14.—Cast trimmer.

the procedure is complete. This will flush most of theparticles from the trimmer drain and help preventclogging.

WARNING

When operating the trimmer, be sure tokeep your fingers away from the wheel.Always wear safety glasses or goggles.

Using light pressure, press the cast against thetrimming wheel. Ensure that the water spray issufficient to contain the grindings.

Check the unit for water leaks and the power cordfor wear or damage. If the unit it does not operatecorrectly, contact the dental equipment repairtechnician. Clean the trimmer at least quarterly, ormore frequently, depending on the amount of usage.

Figure 8-15.—Face-bow.

8-11

FACE-BOW

The face-bow is a mechanical device (fig. 8-15)used to duplicate the position of the maxilla to anarticulator. The face-bow rests on the patient's faceand a wax bite plate is inserted into the oral cavity torecord the patient's bite. Several types of face-bows areavailable for use.

IMPRESSION TRAYS

Impression trays hold the impression material inplace while it sets. The impression may include aportion of the arch or the entire arch. Generally, theimpression tray is shaped to match the natural contourof the arch. The two basic types of trays are stock andcustom trays. With either type, the tray used for themandibular impression differs from the maxillary traybecause it allows free tongue movement.

Stock Trays

Stock trays come in many sizes for both themaxillary and mandibular arches. As figures 8-16 and8-17 illustrate, stock trays may be rimlocking or mesh.Both stock trays are available in regular, edentulous,and orthodontic styles. Generally, the size of a traywill be identified on the handle tray.

Custom Trays

Rimlock trays are easily identified by a rim thatresembles a metal wire soldered along the inner part ofthe tray at the edge of the outer borders. The maxillaryimpression tray has a U-shaped wire soldered to apalatal area on the tray. Semiliquid impression

Figure 8-17.—Maxillary and mandibular mesh stock trays.

material flows into the undercuts (ledges) formed bythe rim and sets (hardens). This locks the material in

the tray.

Use liquid tray adhesive or the spray type on

impression trays to ensure that the impression material

does not separate from the tray. Stock trays are used for

hydrocolloid impression materials. Unless disposable,

stock trays must be cleaned and sterilized after each

patient use.

Custom trays are made in the dental laboratoryfrom tray acrylic. Since custom trays are made for

individual patients, you must have a dental cast of the

patient's teeth. The fabrication of custom trays isdiscussed later in this chapter.

Figure 8-16.—Maxillary and mndibular rimrock stock trays.

8-12

MIXING BOWL

The mixing bowl is made of flexible material,either rubber (fig. 8-18) or flexible plastic, and used tomix alginate impression material and dental stone. Itcomes in small, medium, large, and extra large sizes.All sizes are used in the dental laboratory. A spatula isused to blend the powdered alginate or dental stone andwater together. You may also find that a regular tableknife may be used as a mixing spatula. In either case,the rounded ends on the spatula or table knife shouldapproximate the contour of the mixing bowl.

PNEUMATIC CURING UNIT

The pneumatic curing unit (fig. 8-19) is commonlycalled a pressure pot . I t is used during thepolymerization of self-curing acrylic resins. It is usedto cure relines and repairs of complete and removablepartial dentures. The unit has a compressed air inletthat allows air pressure to fill the pot. Curing of theresin under pressure significantly reduces thepossibility of pores or voids with the resin. Lukewarmwater (115°F) is usually placed in the pot to hastenpolymerization. To use, place the appliance that is tobe cured in the pot. Ensure the appliance is completelysubmerged in the water. Secure the pot top. Fill the potwith compressed air. The normal curing time is 30minutes at 20 psi.

WARNING

You must never exceed the maximum airpressure indicated in the manufacturer'sinstructions. Excessive pressure may causethe pot to explode.

Curing time may vary depending on the thicknessof the resin being cured. After curing, use the air reliefvalve to let the air escape. Ensure that no air pressureremains in the pot when retrieving the cured prosthesisfrom the pot.

Figure 8-19.—Pneumatic curing unit.

Periodically check the seals, air inlets, and outletsfor malfunction. Activate the pressure relief valve toensure it is operational. When necessary, lubricate the"O" ring inside the lid with petrolatum.

VACUUM ADAPTER

The vacuum adapter (fig. 8-20) is used for therapid fabrication of custom trays, stents, mouthguards,and bite guards. This unit is also referred to as thevacuum former. The vacuum former will soften asheet of plastic or acrylic resin and then draw it onto thecast with suction.

Figure 8-18.—Rubber mixing bowl. Figure 8-20.—Vacuum adapter.

8-13

Clean the exterior of the unit and inspect the electricalcord and plug before each use.

The heating element is housed inside a metalassembly at the very top portion of the unit. Thissection will become extremely hot when in use. Usecaution. Before use, inspect the vacuum holes in theplatform to make sure they are not obstructed. Inspectthe rubber sealing gasket for cracks and deterioration.

VIBRATOR

The vibrator (fig. 8-21) is used to move dentalplaster or dental stone mixes when pouring a cast. Thevibrator also increases the density of the mix byeliminating air bubbles. A rheostat control is used toadjust the intensity of the vibration from a gentleagitation to a vigorous shaking.

To maintain the vibrator, cover the rubberplatform and body of the unit with a plastic cover. As asafety precaution, check the power cord and plug fordefects before use.

BASIC PROSTHODONTICINSTRUMENTS

Some of the common prosthodontic instrumentsyou and the dentist will use during patient treatmentand in the fabrication of dental prostheses areexplained in the following paragraphs.

CROWN REMOVER

To remove a crown from a tooth, the dentist uses acrown remover instrument (fig. 8-22). The handle onthe crown remover is encircled with a heavy-steelweight that slides from one end of the handle to theother. Two interchangeable points make up theworking end. One of these points is contra-angled andthe other is straight. Both points have a right-angle

Figure 8-21 .-Vibrator.

Figure 8-22.—Crown remover.

projection at the top. When the crown remover is usedproperly, the tip is placed over the margin or junctionof the crown and tooth first. Then the sliding weight onthe handle is tapped against the bottom part of thehandle.

ROACH CARVER

The roach carver (fig. 8-23) is a double-endedinstrument used to cut, smooth, and carve dentalwaxes. At first glance, it appears to look like a waxspatula. A closer look reveals a spear-shaped blade atone end, with a deep-welled, very small spoon at theother end. Both ends have very sharp edges. Thedeep-welled end may al so be used to carry melted wax.

PROSTHODONTIC KNIVES

Usually, two kinds of knives are used in theprosthodontic treatment room: the compound knifeand plaster knife. As the names imply, one is used withcompound, and the other with plaster.

Compound Knife

The compound knife (fig. 8-24) has a fairly large,red plastic handle and detachable blade. Routinely the#25 blade is used to trim impression compound, wax,and other materials that require an extremely sharpcutting edge. The blade is almost identical to a largerversion of the #11 surgical blade. Your primaryconcern with the compound knife is to replace brokenor dull blades.

Figure 8-23.—Roach carver.

8-14

Figure 8-24.—Compound knife with #25 blade.

Plaster Knife

Figure 8-27.—Wax spatula, #7.

The plaster knife (fig. 8-25) is a heavy-duty knifeused to trim and chisel gypsum products andimpression compound. It has a large flat blade at oneend with a wide projection shaped Ii ke a screwdriver atthe other end. The handle is made of wood and isriveted in place. You must keep its blade sharp.

Figure 8-28.—Wax spatula, #31.

PRELIMINARY IMPRESSIONS

PROSTHODONTIC SPATULASPreliminary impressions are a three-dimensional

record of a patient's dentition and anatomy of thealveolar process. Almost all prosthodontic treatmentrequires preliminary impressions be taken so that adental cast can be made and used by the dentist as adiagnostic tool and to fabricate various prosthodonticappliances.

MATERIALS REQUIRED

Spatulas are used in prosthodontics for handlingdental waxes and mixing impression materials. Thelaboratory spatula shown in figure 8-26 is used to mixthe various impression materials. It has a 2-1/2 inchflexible blade, which is about 1-inch wide with arounded end. The handle is usually made of wood orplastic.

The wax spatulas commonly used are the #7 (fig.8-27) and the #31 (fig. 8-28). Both spatulas are used tohold small bits of wax over a Bunsen burner flame thatdelivers liquid wax.

Figure 8-25.—Plaster knife.

Figure 8-26.—Laboratory spatula.

The dentist may direct you, under supervision, totake preliminary impressiom of the dental arches of apatient. You will need the following materials:

Alginate

Impression trays

Rope-style utility wax

Mixing bowl, spatula

Mouth mirror

Mouthwash

Water

IMPRESSION PROCEDURES

Once you have all your materials standing by, takea few minutes and explain to the patient what isinvolved in the impression procedure. The key totaking good impressions is to have the correct sizeimpression tray fit the arches, to mix the alginate,position the tray correctly in the mouth, have thepatient relax and breathe through the nose, let the

8-15

alginate set, and correctly remove the impression tray.Use the fol lowing steps to take prel iminaryimpressions:

1. Select the correct size impression tray andensure its fit in the patient's mouth is correct. Allow 3-4mm of space between the tray, teeth, and soft tissueswhen the tray is positioned in the mouth.

2. Place utility rope wax around the top border ofthe maxillary and mandibular trays to extend theirheight. This will also act as a "pad effect" on the softtissues. Place the trays in the mouth again to ensure thefit.

3. Mix the alginate and water together in themixing bowl with a spatula. Follow the manufacturer'sinstructions. Mix into a creamy, smooth consistency.Use the sides of the mixing bowl and press the mixtureagainst it to eliminate air bubbles. Total mixing time isusually 1 minute depending on the type or manufactureof alginate used.

4. Have the patient rinse with mouthwashvigorously. This aids in removing food particles andthick saliva that may cause voids in the impression.

5. As the patient is rinsing, load the maxillary traywith the mixed alginate. Load the tray with one largeportion of alginate on the spatula using a wipingmovement to avoid air being trapped in the material.

6. Wipe off any excess alginate, and smooth thesurface of the tray with your index finger. Use theexcess alginate from the mixing bowl and place somedirectly onto the palate with your index finger beforeseating the impression tray. This prevents a large voidwithin the palatal vault.

7. Have the patient open his/her mouth abouthalfway. Using your left index finger, retract thepatient’s right cheek. Carefully place the filled tray intothe patient's mouth and use the tray to move the leftcheek out of the way.

8. Guide the tray in the mouth and center it over themaxillary teeth. Pressing up with the posterior border ofthe tray, raise the tray to the hard palate area to form aseal.

9. Keeping the posterior border of the hard palatein place, next raise the tray up over the maxillary teeth.The tray should be seated so that it is parallel with theocclusal plane.

10. Holding the tray in place with your right hand,use your left hand to gently lift the patient's lips andcheeks away from the tray until it is completely seated.

The maxillary arch should now be completelyem bedded in the alginate material.

11. While keeping the tray parallel with the occlusalplane, pull the upper lip over the anterior border of thetray to form the anterior section of the impression. Theaverage working time from mixing the alginate materialto this step is 1 1/2 minutes. After this time, the alginatebegins to gel and set up.

12. Still holding the tray in place, look in thepatient's mouth and ensure that no alginate material isrunning down into the throat area. If needed use amouth mirror to remove any excess. Have the patientrelax and tilt the head down and breathe through thenose as the material is setting up. A saliva ejector orpatient napkin needs to be in place to catch any excesssaliva while the alginate is setting up.

13. After the alginate has set, place one of yourindex fingers along the lateral border of the tray andpress down to break the seal formed by the set alginatematerial. Once the seal is broken, carefully remove thetray from the patient's mouth and wrap the tray in amoist paper towel. Have the patient rinse his/her mouthout to remove any excess material left from theimpression. Have the dental officer inspect themaxillary impression for accuracy.

14. Next, take the mandibular arch impression usingthe same basic steps as with the maxillary archtechnique. When seating the mandibular tray onto thelower arch, have the patient raise the tongue to allow thealginate in the tray to take an accurate impression of thelingual aspects of the alveolar process.

15. Once the tray is seated, gently pull the lower lipover the anterior border of the mandibular tray to formthe anterior section of the impression.

16. After the alginate has set, remove themandibular tray in the same fashion as with themaxillary arch, except push up to break the seal.

17. Have the patient rinse his/her mouth again, andhave the dental officer inspect the mandibularimpression for accuracy. Wrap in a moist paper towel.

18. The dental assistant will now disinfect themaxillary and mandibular impressions. While in theDTR, remove the moist paper towels. Rinse anddisinfect using an accepted phenyl disinfectant on theimpression material and trays. Wrap in moist papertowels again and place impressions in a headrest coverfor transportation to the dental laboratory.

8-16

FABRICATING CAST

The laboratory technicians will usually pour mostof the impressions, but there will be times when youmust perform this task. To fabricate a quality cast, youmust first start with a quality impression.

PREPARING TO POUR IMPRESSIONS

Once you have an accurate impression, producingan accurate cast is simple if the impression andmaterials are prepared correctly. A minor mistake inany of these areas could cause a distorted cast.

IMPRESSION

Pour the impressions as soon as possible becauseall impression materials are subject to distortion.Cleanse impressions to remove mucous and saliva.This helps to ensure accurate surface detail and

eliminates the chance of soft spots in the cast. Tocleanse the impression, rinse it under cool tap water, orlightly sprinkle stone into the impression andthoroughly rinse the stone away. If there is heavymucous and blood in the impression, you might need tobrush it lightly with a large soft sable paint brush.Remove excess moisture by gently shaking theimpression. Never dry an impression or use an air blastto remove moisture because you might distort or tearthe, impression material. Figure 8-29 illustratescommon problems with alginate impressions.

MATERIALS AND MIXING

To produce a good cast from the impression, youneed to use a properly mixed gypsum product. Mostoften you will use hydrocal (dental stone). To assure agood cast mix, perform the following steps.

Figure 8-29.—Common problems with alginate impressions.

8-17

1. Always use a clean mixing bowl and spatula.The best time to clean a bowl and spatula is immediatelyafter pouring the impression while the material is stillsoft and easy to remove.

2. Measure the volume of water and weigh thepowder before you mix any gypsum material. Anaccurate water-to-powder ratio is a must to preserve theproperties of any gypsum product.

3. Always add the powder to the water, never thewater to the powder.

4. Spatulate thoroughly by hand, incorporating althe powder evenly throughout the mix until creamyAvoid whipping the mix; doing so will cause the finalproduct to have excessive air bubbles.

5. Vacuum mix using a power mixer-investorwhenever possible. Vacuum mixing helps to eliminateincorporation of air into the mix. If you can't vacuummix, tap the mixing bowl against the bench top or hold iton the vibrator for a few moments to express any air thatmight be trapped in the mix.

6. Never add water to a mix that is too thick; thisinterferes with the setting properties. It would be betterto discard the mix and start over again.

POURING IMPRESSIONS

The primary objective when you pour a cast is tocapture all the surface detail of the impression, and asbubble-free as possible. This is done using a vibratorto make a thick gypsum mix, which flows into all thecrevices of the impression. There are several ways topour impressions, such as the upright, two-step, andboxed methods. We will only discuss the two-stepmethod of pouring a cast, because it is the mostsuccessful method of pouring preliminary and finalimpressions.

First Pour

Begin by holding the impression tray so that thehandle rests against the vibrator. Start at one end of thearch and flow a small amount of stone into theimpression, letting it slowly advance to the other sideas shown in figure 8-30. Flow the stone slowly enoughto watch the progress of the stone as you fill each toothimprint. This should eliminate bubbles. If a bubbleappears and does not go away with vibration, pop itwith a small instrument. Use an acrylic mixing spatulato place small amounts of stone into minutepreparations or teeth with wide incisal and narrow

cervixes. Touch the impression to the vibrator to floweach addition of stone.

After covering all the critical surfaces of theimpression, you may safely add progressively largeramounts of the mix. There is a rate of vibration that isbest for each mix's ability to flow. The vibrationintensity should be set high enough to make thematerial move across the surface of the impression.The vibrator is set too high if the impression "jumps" inyour hand, moves so fast that it skips over surfacedetail, or if vibration wave patterns develop on thesurface of the mix. Continue filling the impressionstone to a level slightly above the height of theimpression walls (about 2 mm thick). Do not flowstone over the outside of the tray because it must beremoved before the impression can be separated fromthe cast.

Lastly, add retention nodules to this first pour asshown in figure 8-31(A). Stone retention nodules areused between the first and second pours so the twostone layers can be locked together mechanically.Place the handle of the tray in a holding device; do notlay the impression on the counter or the cast will bedistorted. Now let this first pour set for about 45minutes, or at least until the stone loses its glazedappearance before making the cast base.

Second Pour

It is now time for you to make the cast base. Usethe cast trimmer to grind down the long retentionnodules (if completely set), reduce the base of thecast's thickness, and make the top of the tray parallel tothe cast's bottom. In general, the length of the retentionnodules should equal the height of the trav flanges.

Figure 8-30.—Pouring the first pour of an impression.

8-18

Figure 8-31.—Two-step method of cast fabrication.

With a second mix of stone, form a patty for the base.Add stone around the retention nodules and invert thefirst pour into the patty. Now use you spatula to shapethe sides of the cast base as shown in figure 8-31(B).Take care not to bring stone up onto the trayembedding the tray into the base. With a mandibularcast, you must take time to smooth and contour thetongue space while the second mix is still soft.

TRIMMING CAST

Casts should present as neat and attractive aspossilbe. After the heat generated by the final settingreaction dissipates completely (about 45 minutes),trim any stone from the outside of the tray with aplaster knife and separate the cast from the impressionas shown in figure (8-31(C). Do not hurry and force thetray or you may break off some teeth, especially if thetray is embedded in the base. If a cast is not separatedfrom an alginate impression before the alginate showssigns of dehydration, the cast will probably showunacceptable surface damage.

PRELIMINARY STEPS

Before trimming the cast, you must soak it in asaturated dihydrate solution (SDS). Never trim a drycast because the slushy debris coming off the trimmingwheels will fall on the dry surface and become

permanently attached to the cast surface. Mark the castwith trimming lines. These lines will help youdetermine the base thickness; align the base plane tothe occlusal plane of the teeth; and trim the outerboundary alongside the posterior teeth, the anteriorteeth, and the posterior border of the cast.

TRIMMING

Figure 8-32 shows the desired cast dimensions of atrimmed cast. Start trimming the cast by grinding thecast bottom parallel to the occlusal plane of the teeth.The cast should be about 15 mm (5/8 inch) thich at itsthinnest place (usually the palatal vault of the upperand the tongue space region of the lower). Make surethe cast includes all the denture support areas and all ofthe features that define denture borders. Keep the castfree of nodules or voids. When trimming a maxillarycast, make it as much like the general shape shown infighre 8-32. Trim a mandibular cast to correspond withthe shape shown in the same figure. Fully represent thesulci area in the cst, but not more than 3 mm deep. Thesulci are routinely protected by a peripheral "land"area or ledge extending 4 mm outward. Make sure thecast extends 5 mm beyond the hamular notch area ofthe maxillary arch and 5 mm beyond the retromolarpads of the mandibular notch.

8-19

Figure 8-32.—Trimmed maxillary and mandibular cast.

FABRICATING CUSTOM IMPRESSION method and the vacuum method. We will limit thisTRAYS discussion to the more frequently used dough method.

Prefabricated trays are made to fit everyonemoderately well, but will not fit anyone very well. Onthe other hand, a custome tray provides a dentist with animpression material carrier that permits the dentist tomake a more accurate impression that they could makeusing a stock (prefabricated) tray. The custome tray ismade on a diagnostic cast. The dentist draws theborder outlines of the proposed custom tray on thediagnostic cast, as shown in figure 8-33(A), and givesother directions, such as handle position and the needfor vertical stops. You may then make the tray so itconforms to the design. Two of the most popular waysof making custom trays are self-curing resin dough

SPACERS

The dentist will usually prefer a custom tray thatprovides room for a controlled thickness of impressionmaterial. Spacers used to develop vertical tissue stopsaccomplish this purpose. The stops are made to holdthe tray off the cast by a distance equal to the thicknessof the spacer. When the spacer is removed and the trayis placed in the patient's mouth, the stops hold the innersurface of the tray out of contact with the patient'stissue. The subsequent space between the tray andtissue is then later filled with impression material.

Figure 8-33.—Design and blockout for a custom tray.

8-20

FABRICATING TRAYS WITHOUTSPACERS

Custom trays for complete denture patients areoften made without spacers and adapted directly to theridge. If a spacer is not used for tray construction, theundercuts on the cst must be eliminated very carefullyusing baseplate wax. Failing to do so will result in adamaged cast or tray when you attempt to remove thehardened tray.

Preparing the Cast

First, paint the cast with two layers of tinfoilsubstitute to prevent the acrylic resin from sticking.Next, use baseplate wax to generously block out (fillin) all undercuts within the tray area outlined on thecast as shown in figure 8-33(B).

Mixing the Resin

Using premeasured amounts of monomer andpolymer, add the powder to the liquid and mix thematerials. Allow the mix to set until it reaches thedoughy stage.

Adapting the Resin

Use a simple stone mold to control the shape andthickness of the resin dough. This preshaped resinmass results in a tray of consistent quality whenadapted to the cast.

Lightly coat your fingers with petrolatum beforeplacing the dough in the stone mold. Be sure the moldis also coated with petrolatum. Cover the dough with amoistened polyethylene sheet. Quickly roll out theresin to match the mold's shape and thickness as shownin figure 8-34(A). Trim away the excess dough and liftthe acrylic resin blank from the mold.

Center the resin over the cast and rapidly adapt thedough by hand to the cast's surfaces. Be careful not tocreate thin spots by pressing too hard. Shape the resinto the borders and cut away the excess with a sharpknife as shown in figure 8-34(B).

Next, attach the handle to the tray, ensure thehandle is strong enough to withstand considerableforce, and that its shape will not interfere with lipmovement. Mix another small amount of tray resin.When polymerization reaches the dough stage, form itinto an L shape. Use a few drops of monomer tomoisten the attachment site between the handle and thetray. Press the handle onto the moistened area. Thefluid ;monomer should provide good bonding. If youwork fast enough, you should be able to use theunpolymerized excess from the first mix for the handleas shown in figure 8-34(C).

Finishing the Tray

After the acrylic has set, remove the tray from thecast and remove any wax adhering to the inside of thetray. Trim the tray's flanges back to the peripheral

Figure 8-34.—Fabricating custom trays using the dough method.

8-21

border markings as drawn by the dentist and shown infigure 8-34(D). Use the bench lathe with an arbor bandto remove bulk. The posterior border of the maxillarycustom tray is supposed to extend a short distance ontothe soft palate. Mandibular custom trays cover theretromolar pads. Use acrylic finishing stones and bursfor finer details. Be sure there are no sharp edges on thetray's borders.

FABRICATING A TRAY WITH SPACERS

The preceding paragraphs described trays thatwere closely adapted to the diagnostic cast. Incontrast, custom trays for fixed restorative patientsare always made over wax spacers. The design for thistype of tray appears in figure 8-35(A). With theexception of the tray's design and the use of a waxspacer, the procedures for fabricating a fixed customtray are the same as we mentioned before. Let's brieflylook at the differences.

Applying a Wax Spacer

After the dentist traces the outline on thediagnostic cast, you can fill the undercuts, and adapttwo layers of baseplate wax to the tray area on the cast.Adapt each layer of wax, one layer at a time. Cut outfour small pieces of the baseplate wax over the crest ofthe ridge areas outlined in the molar and cuspid regions

for tissue stops as shown in figure 8-35(B). Removethe spacers from the cast and apply a tinfoil substituteto the gypsum surfaces of the cast to prevent the acrylicresin from sticking. Place the spacer back on the castand apply a thin layer of petrolatum to the surface ofthe baseplate wax. This will make removal of the waxfrom the polymerized tray easier.

Fabricating the Tray

Use the self-curing dough method to make the tray.After the resin is hard, remove the tray from the castand pull the baseplate wax off the tissue surface of thetray. (Four tissue stops should appear on the ridgeareas where the four pieces of baseplate wax wereoriginally cut out.) Trim any excess acrylic resin to theoutline border on the cast. Round and smooth theborders of the tray. Your finished trays should appearlike those in 8-35(C). Be certain to clean away alltraces of petrolatum that might be present on thetissue surface of the tray. (Sandblasting does thisvery effectively.) Clean and disinfect the tray, place iton the cast for storage.

FABRICATING MOUTHGUARDS ANDVACUUM-FORMED TEMPLATES

In addition to pouring and trimming study casts,and fabricating custom trays, you may be called upon

Figure 8-35.—Fabricating custom trays over wax spacers.

8-22

to fabricate mouthguards and vacuum-formedtemplates. Many of the steps involved in fabricatingthese devices are similar and fairly simple to learn.

FABRICATING MOUTHGUARDS

Mouthguards are constructed of acrylic resin orvinyl-like material that covers and protects all of theteeth in the arch. The purpose of a mouthguard is toreduce the potential for injury to the teeth andsurrounding tissues. Although a mouthguard does notprevent the teeth from fracturing, it does keep thefragments from lacerating or embedding in the oraltissue. The mouthguard also reduces the risk ofconcussion by acting as a shock absorber. If the head isimpacted, the guard cancels part of the force, reducingthe risk of concussion.

Preparing the Cast

The first step in fabricating a mouthguard is todraw the outline of the mouthguard on the cast with asoft lead pencil. Design the mouthguard by drawing orscribing a line around the maxillary arch in the buccalflange area to the highest point to which you want thematerial to extend. Normally, the mouthguard extendsto the point where the soft tissue meets the attachedgingiva. Next, trim the working cast as close to theoutline as possible as seen in figure 8-36(A). Thethickness of the cast base should not exceed 6 mm. Thereason for trimming the cast as specified is to facilitatethe cacuum formation and to minimize stretching andthinning of the vinyl plastic during the molding. Forthe same reason, drill a hole in the palate with a largepear-shaped bur. Soak the cast in water for a couple ofseconds to prevent the hot thermoplastic material fromadhering to the cast. Remove excess water from thecast. Place the wet cast on the perforated plate of avacuum-forming device.

Vacuum-Forming the Mouthguard

Several different types of vacuum-formingmachines can be used to adapt thermoplastic material.Most machines consist of a perforated plate connectedto a source vacuum, an electrical heating element, anda metal frame in which the vinyl plastic blank can beclamped. Regardless of the machine's manufacturer,the procedures used to adapt the material are basicallythe same. The construction procedures, in general,consist of the following steps:

1. Clamp a vinyl plastic blank in the frame, andplace it in position to be heated. The moldingtemperature usually is estimated by the amount thesheet of vinyl plastic material "sags" as it softens (fig.8-36(B)). Excessive heating of the material will causethe mouth protector to stretch and thin out. Sharpreproductions of the surface detail are not necessary.

2. When the material is ready, turn the vacuum onand move the frame to the molding position (fig.8-36(C)). Hold it in this position until the vinyl plastic iscompletely adapted to the contours of the cast.

3. Turn off the vacuum. Release the clamp on theframe and set the cast with the mouth protector asideuntil it cools completely.

Completing the Mouthguard

Trim excess material away with scissors as shownin figure 8-36(D). Heat a Bard-Parker blade and trimthe outl ine of the mouthguard. Remove themouthguard and reduce the borders to approximately5-7mm. A large bur, arbor band, or finishing stonemay be used to reduce the border thickness. Polish theedges with pumice, or lightly flame the mouthguardwith an alcohol torch. Flaming has the benefit ofclearing any cloudy areas in the material. Wash anddisinfect the mouthguard, then place it in a prostheticdenture bag for delivery to the patient.

The completed mouthguard should conform to thegeneral outline presented in figure 8-36(E). Noticethat the posterior border of the maxillary mouthguardends on the hard palate, and that the facial flanges donot restrict the movement of any frena. The posteriorborder may end in the rugae area to increase thepatient's speech and comfort.

FABRICATING VACUUM-FORMEDTEMPLATES

Provisional fixed restorations (temporaries) areusually made using some type of matrix or template.Two methods more commonly used for providingthese templates are the impression method and thevacuum-forming method. Basically, the template orimpression is a shell that will be filled later withtooth colored resin and seated on the prepared teeth,forming the provisional restoration. For this purpose,we will only discuss making a template using thevacuum-forming method since you are alreadyfamiliar with how to make an impression.

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Figure 8-36.—Fabricating mouthguards.

Vacuum-formed templates are made using clear Heat the material until it sags about 1 1/2 to 2 inches,splint material (.020-inch), a vacuum-forming and vacuum-form the clear splint material over themachine, and a cast. If the teeth that the dentist intends cast. At first, the material appears cloudy and then willto prepare have large cavities, fill in the defects with become clearer. You know the material is overheateddental cement and carve the cement to the proper when you begin seeing small bubbles appear.shape. If the temporary prosthesis is for a proposedFPD site, also adapt spare resin denture teeth to theedentulous space as shown in figure 8-37. Sticky waxthem in place and if needed, adjust the occlusion.

Splint material is not pliable like mouthguardmaterial, making it difficult to remove from the grosssoft tissue undercuts that may be present on the cast.Use a heated Bard-Parker knife to cut away the excessmaterial in the sulcus areas and around the base of thecast. You should now be able to pry the arch form

Place the cast on the vacuum-forming machine andmount the plastic sheet below the heating element.

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space.Figure 8-37.—adapting a denture tooth to the edentulous

template off the cast for final trimming with scissors.Cut out the section needed for the provisionalrestoration plus one or two uninvolved teeth anteriorand posterior to it as shown in figure 8-38. When youare finished, clean and disinfect the template; andplace it and any of the unused arch sections back on thecast so they won't distort. Often, subsequentrestorations are made for the same patient, and theunused arch sections are kept in case they will beneeded at a later date.

SIMPLE ACRYLIC REPAIRS

Occasionally, you will be required to performminor repairs on complete and removable partialdentures. These repairs may include fractureddentures, or replacing fractured, missing or loose teeth.These repairs may be caused by changes in the oraltissues, careless handling, etc. The dentist will decidedif any impression of the patient's mouth is needed forthe repair, and will tell you what needs to be done tocomplete the repair. Since every repair is a littledifferent, these next procedures describe some, but notall, of the possible repair solutions. If you needassistance, refer your questions to the dentist orprosthetic technician.

DENTURE BASE REPAIRS

Figure 8-39 shows a simple denture base fracture.The repair procedures will include aligning thefractured parts, pouring a plaster cast (matrix),

Figure 8-38.—Trimming away excess material with scissors.

Figure 8-39.—Simple denture base fracture.

widening the fracture line and making retentivegrooves, applying self-curing acrylic resin, adjusting,and polishing. When the pieces of the denture basecannot fit against one another in a precise relationship,or one or more fragments have been lost, this type of afracture is classified as complex. Since complexfractures should be repaired by prosthetic technicians,they will not be covered in this chapter. To repair asimple denture base fracture, perform the followingsteps (A-H) shown in figure 8-40:

1. Align the fractured denture parts and applysticky wax over the fracture line on the external surfacesof the denture.

2. Stabilize the parts by positioning denture burswith sticky wax as shown in step A.

3. Block out all undercuts on the internal surfacethat will be exposed to the plaster with a wet pumice mixor block out wax (step B). Do not block out undercutsalong the fracture line. Blocking out the undercutsenable you to remove the plaster cast after it sets.

4. Prepare a plaster mix.

5. Slowly pour the plaster into the internal surfaceof the denture. The plaster cast should cover the fractureline, but not the entire denture. This procedure isaccomplished by holding the denture in you hand andgently resting it against the vibrator.

6. Place the denture in an upright position (step C)and allow the plaster to cure.

7. Once the plaster is set, gently remove it from thecast.

8. Remove the denture burs and all traces of thesticky wax and pumice.

9. With a new denture bur, widen the fracture lines(step D) on the denture and place retentive groovesalong the fracture line.

10. Paint two thin, even coats of tinfoil substitute onthe cast (step E).

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Figure 8-40.—Denture base fracture repair steps.

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11. Align the denture parts on the cast and hold themin place with sticky wax at the posterior edges (step F).

12. Prepare the self-curing acrylic resin.

13. Moisten the brush with monomer and dip it intothe polymer (powder), and apply it to the fractured area.Repeat this procedure until the fracture is covered andslightly overfilled.

14. Allow the denture to stand for a few minutesuntil the sheen of the resin disappears from the surface.

15. Place the denture and the cast in a pneumaticcuring unit (step G).

16. Cover the denture with lukewarm water (115°F)and secure the lid.

17. Attach the rubber tubing to the air valve on thelid and till with compressed air to 20 psi.

18. The curing process will take 30 minutes.

Note: If a pneumatic curing unit is not available, placedenture and cast in a bowl of lukewarm water for 30minutes or until the resin hardens. This is not therecommended procedure but may be used inemergencies.

19. Gradually turn the air release valve on the lid torelieve the inside pressure. When the pressure gaugereads zero, carefully remove the lid.

20. Remove the repaired denture base from thepressure pot.

21. Using a denture bur, trim all excess acrylic fromthe denture (step H).

22. Polish the external surfaces with pumice and amuslin or brush wheel that is mounted on a bench lathe.If a lathe is not available, you may use a mandrel-mounted wheel on a straight handpiece.

23. Disinfect and place denture in a prosthetic bagwith water for delivery.

DENTURE TOOTH REPAIRS

The original tooth can be reattached if it is stillintact, but some repairs will require a new denturetooth. The following procedures describe simpledenture tooth repairs that do not involve the facialdenture base plastic (complex fracture). The examplegiven is of an anterior tooth that fell out. If the facialdenture base plastic needs repair, a prosthetictechnician or a dental officer will perform the repair.To accomplish a denture tooth repair, perform thefollowing steps (A-F) as shown in figure 8-41:

1. Roughen the lingual aspect of the acrylic teeth toguarantee good chemical bonding with the repairmaterial. Use an inverted bur to undercut a hollowopening in the lingual aspect of the acrylic tooth.

2. Make a box preparation (step A) in the denturebase, lingual to the tooth to be repaired.

3. Position the tooth (step B) in its seat and stickywax it in place from the lingual.

4. Construct a plaster cast facial matrix to hold thetooth in position during repair. It should include thetooth that is being repaired and the tooth on each side(step C).

3.clean all wax from the box preparation (step D).

After the plaster has set, remove the matrix and

6. Paint the matrix with a tinfoil substitute (step E).

7. Reassemble the denture, the tooth, and thematrix in correct aligment. Sticky wax the tooth to thematrix, and the matrix to the denture (step F).

8. Place self-curing resin to the repair area in thesame manner as described in the denture base repairsection. Build up the repair resin slightly higher than thesurrounding denture base.

9. Place the tooth repair in a pneumatic curingunit and follow the same steps as described in thedenture base repair section for curing, finishing, andpolishing.

10. Disinfect and place the repaired denture in aprosthetic bag with water.

PROSTHODONTIC CHAIRSIDEASSISTING

The basic clinical procedures are essentially thesame as in all direct patient care in dentistry. Theprosthodontic procedures, sequence of treatment, andmaterials required vary with the specific treatmentrequirements for the patient and the individual dentist.This section covers the basic chairside duties aprosthodontic assistant performs with a dentist.In-depth techniques and procedures should be learnedfrom on-the-job training.

Most prosthodontic cases require a series ofappointments. It is your duty as the assistant toschedule these appointments. Two basic factorsinfluence the scheduling of prosthodontic patients:

The procedures to be done during theappointment

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Figure 8-41.—Anterior denture tooth repair steps.

The laboratory t ime required between

appointments

These factors will, of course, dictate the timeallocation and date for which you should reschedulethe patient. Each new prosthodontic patient requires

an evaluation that may include complete oralradiographs. The dentist uses the radiographs todiagnose cysts, residual roots, unerupted and impactedteeth, periodontal conditions, caries, bone density, ortoher conditions requiring restorative or surgicalcorrection before prosthodontic treatment is started.

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At the evaluat ion appointment, prel iminaryimpressions are made and diagnostic casts are thenpoured from the preliminary impressions

USE AND COMPLETION OFDD FORM 2322

Whenever dental laboratory work is required tosupport prosthodontic treatment, a DD Form 2322,Dental Laboratory Work Authorization (figs. 8-42),must be completed. This triplicate form has severalpurposes. It contains patient information andfabrication instructions, and is used as a preciousmetals voucher and an entry from for compositelaboratory value (CLV) codes.

The responsibility for initiating the patient data forthis form is usually delegated to the dental assistant. Indoing so, you must take care to fill out the formcompletely and accurately. The dentist will fill inblocks 15-28. It advises the laboratory, in writing,exactly what materials to use and the services to beprovided. An incomplete or inaccurate form mayresult in the lact of necessary items required tofabricate the prosthesis.

FIXED PROSTHETIC PROCEDURES

Most steps in tooth preparation for crowns andFPDs are similar. The number of appointments tocomplete the fixed prosthesis will vary depending onwhat is being fabricated. A single metal crown can bedelivered in 2 to 3 appointments; whereas, a porcelainfused to metal crown or bridge usually requires 3 to 4appointments. A basic prosthodontic tray setup isillustrated in figure 8-43. You should becomethroughly familiar with each instrument andunderstand its use. The basic steps involved at thisappointment involve selecting a shade (if porcelain isused), preparing the tooth or teeth, making the finalimpression, and preparing and cementing thetemporary restoration.

Shade Selection

Before any tooth preparation, it is best if the dentistselects a tooth shade. Each manufacturer provides anumber of different colors in its porcelain system and ashade guide for use in the selection of the tooth color.One the shade is selected, ensure that you or the

Figure 8-42.—Dental Laboratory Work Authorization, DD Form 2322 (Front and back).

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Figure 8-43.—Basic instrument tray setup for prosthodontic treatment.

dentist record the information in block #13 of DD

Form 2322.

Preparation

The primary purpose of the initial tooth or teeth

preparation appointment is to remove tooth structure,

and provide adequate space for the crown or bridgebeing made. The initial preparation of the tooth is

accomplished with a tapered diamond bur in an

ultra-speed handpiece. The dentist must reduce the

tooth for the crown or bridge so that it is thick enough

to provide for an adequate amount of strength, without

increasing the size of the tooth. The basic procedures

of tooth or teeth preparation you will assist in are:

If the tooth or teeth have not been endodonticallytreated, the dentist will administer dental anesthesia.

Isolate the working area by using cotton rolls andretract the cheek, lips or tongue, and evacuate debrisduring the removal of tooth structure.

Assist in placing gingival retraction cord whenthe dentist creates the margin of the preparation so asnot to damage the supporting structures of the freegingival margin. The dentist may have you take a pieceof retraction cord and place it in a hemostatic agent thatassist with control of hemorrhage.

The cord is placed into the gingival crevice witha flat-bladed instrument (fig. 8-44) and then the end ofthe cord is cut and the preparation finalized.

Final Impression

After the dentist is satisfied with the preparation,you will prepare the materials for the final impression.A custom tray has usually been fabricated for thisappointment. Preparation for the tray impression

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Figure 8-44.—Placing gingival retraction cord into gingivalcrevice.

actually begins during tooth preparation at the stagewhen the gingival area is isolated with retraction cord.A properly positioned cord serves two functions:

It displaces the free gingiva for completing thetooth preparation.

It opens the gingival sulcus for the impression.

Before you prepare the impression materials, youmust paint the custom tray with a tray adhesive that iscompatible with the impression material. Be sure toaccomplish this well in advance to allow the adhesiveto set.

At this stage, one end of the cord should protrudefrom the sulcus so it can be easily grasped with cottonforceps for removal before injecting the impressionmaterail into the gingival sulcus. Additionalpreparation of the mouth for the impression includes,irrigation, aspiration, and isolation of the preparationsite with clean dry cotton rolls.

The impression materials that the dentist willselect for use may be light-cured, or supplied as atwo-paste base and catalyst system that is mixed inequal length. Some manufacturers market thetwo-paste impression materials in a manner thateleminates the need to manually mix the material.These materials are mixed using a gun-l ikedispenser, which is loaded with twin tubes ofcatalyst and base. Whatever material the dentistchooses, always refer to the manufacturer 'sinstructions to mix the material.

Usually, impression material of two differentviscosities (bodies) are used. You will prepareregular-bodied material and load it into the customtray, and also prepare a light-bodied material and loadit into a syringe (if not using the gun-like dispensermethod). As the retraction cord is removed, the dentistinjects the light-bodied material around the sulcust ofeach individual tooth preparation. During thisprocedure, you assist with retraction of the lip, cheeksand/or tongue, and have the impression filled custom

tray ready for insertion. Once the dentist seats the tray,you will place a saliva ejector in the patient's mouth toremove excess saliva while the impression materialsets. Once set, the dentist removes the impression andinspects it for quality. Allow you patient to rinse withwater, and provide a hand mirror and tissue to allowthem to clean excess material from the face. Beforeyou take the impression to the laboratory, be sure todisinfect it according to current infection controlstandards.

Bite Registration

The dentist may determine that an accurate biteregistration is necessary to establish the properocclusal relationship during mounting. A biteregistration can be made in many ways. Some of thecommon methods use reinforced bite registration wax,or dental stone mixed with slurry water (water frommodel trimmer).

Interim (Temporary) Crown or FPD

The last step in this appointment is that atemporary crown or FPD must be made to cover andprotect the prepared tooth or teeth while the permanentprosthesis is being fabricated. To protect toothsensitivity, the temporary should extend to the marginof the tooth preparation but not beyond it. A temporarythat extends beyond the margin into the gingivaltissues will become an irritant to the tissue. A properlyconstructed temporary will have the followingcharacteristics:

Provides the appropriate occlusal form andrelationship to any opposed teeth.

Smooth and polished so it does not irritate thetongue, lips, cheeks, or gingival tissues.

Provides appropriate proximal contactrelationships with unprepared adjacent teeth toprevent drifting.

Provides acceptable esthetics if placed in ananterior area.

Temporary crowns or FPD's can be constructedfrom preformed acrylic resin and aluminum shells.Plastic stints and alginate impressions can also be usedwith self-curing acrylic resin to make an interimprosthesis.

When the temporary is finished, a temporarycement such as zinc oxide and eugenol is used todeliver the interim restoration onto the prepared toothor teeth. Consult the manufacturer's instructions for

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proper mixing of the material. After the temporarycement has set, use the mirror and explorer to gentlyremove all excess cement from the crown and gingivalarea. Check the patient's occlusion again and allowyou patient to rinse his/her mouth with water toremove any debris or loosened excess cement.

A t t h e e n d o f t h i s a p p o i n t m e n t , m a k earrangements for future visits before dismissal of thepatient. Be sure to annotate the DD Form 2322 with thedate, time, and step of the next treatment planned. Thisinformation is essential to the dental laboratory forfabrication of the requested work.

INSERTION OF FIXED PROSTHETICS

The basic steps involved in inserting crowns andfixed FPDs are the same. Your instrument tray setupfor insertion is the same as shown in figure 8-43. Youwill need to include assorted stones and burs foradjustment of the prosthesis. Usually, local anesthesiais not required since most patients can tolerate theminimal discomfort associated with the insertion of theprosthesis. The basic steps in delivery of the finalprostesis include removal of the temporary, try-in andadjustment, s tain and glaze, and permanentcementation.

Removal of the Temporary

The removal of the temporary is usually delegatedto the dental assistant. Do this gently since your patientusually does not have anesthesia and may experiencesome slight sensitivity. Use the following steps whenremoving a temporary:

1. Use an instrument, such as a stellite, to loosenthe temporary bond at the margin of thetemporary.

2. Once removed, clean any debris or retainedtemporary cement on the tooth or teeth with acotton pellet and cotton forceps.

Try-In

One of the first steps in the try-in of the prosthesisis the adjustment of the proximal contacts. Proximalcontacts between adjacent teeth should exist, but benonwedging. The proper amount of contact existswhen there is a slight snap of dental floss as the dentistpasses it through the contact areas. The dentist willcheck other aspects of the prosthesis as follows:

Ensures the prosthesis is fully seated.

Evaluates the pontic adaptation visually, andthen passes dental floss between the pontic tip and thetissue ridge to ensure very little, if any, pressure is on theresidual ridge mucosa.

Uses articulating paper to mark any areas ofinterference between the prosthesis and the opposingteeth, and then reduces them with dental stones and bursin a dental handpiece.

If the prosthesis is completely metal, any surfaceroughness resulting in clinical adjustments iseliminated, and the metal is highly polished beforecementation.

Stain and Glaze

If the prosthesis involves porcelain, the dentist willstain and glaze the porcelain to characterize theporcelain for maximum esthetics. Unstained andunglazed porcelain is referred to as being in a bisquebake state. Before the prosthesis can be cemented, itmust be returned to the laboratory to fire the stain andglazed porcelain. After glazing, the laboratory willhighly polish the exposed metal of the prosthesis. Theprosthesis is now ready for cementation.

Cementing the Prosthesis

The final step in this appointment is the cementingof the prosthesis. The treatment site must be kept cleanand dry throughout the procedure.

Zinc phosphate (ZnPO4) and glass ionomercement have been recognized as excellent permanentcementing agents for fixed prosthetics. ZnPO4,however, is highly acidic during the initial settingstage because of the presence of phosphoric acid.Therefore, ZnPO4 can be quite irritating to the pulptissues if the cementation process is not handledproperly. Some dentist prefer to coat the preparationwith copalite varnish before cementation with ZnPO4.Other permanent cements such as reinforced Zincoxide and Eugenol (ZOE), ethoxybenzoic acid (EBA),and polycarboxylate (PCA) cements are less irritatingto the pulp tissues, but have not proved to be clinicallysuperior to glass ionomer as a permanent cement. Youmust follow the manufacturer's instructions fordispensing and mixing the particular cement selected.

To accomplish cementation of FPD, performthe following steps A through C shown in figure 8-45:

1. Isolate the treatment site with clean, dry cottonrolls, and gently dry the prepared tooth or teeth with agentle blast of warm air or cotton pellet (step A).

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2 . P repare the cement accord ing to themanufacturer's instructions.

3. Carefully place mixed cement into each retaineror crown in a manner that eliminates the possibility oftrapped air.

4. The dentist seats the prosthesis over theprepared tooth or teeth and applies firm finger pressurewith a cotton roll to the occlusal or incisal surface toexpress the excess cement (step B).

seating.

5. For posterior areas, the patient is instructed tobite firmly into balsa wood, orange wood stick, or acotton roll that is placed over the prosthesis for the final

6. While the cement is still fluid, the dentist uses asharp explorer tip to examine the marginal fit and verifythe seating of the completed restoration.

7. Place a saliva ejector in the patient's mouth toensure the area remains dry while the cement sets.

8. Do not attempt to remove excess cement until ithas set to the point of being "brittle-hard".

9. When hard, use an instrument such as aperiodontal curette, to remove all cement from aroundthe restoration, tooth, and the gingival sulcus area (stepC).

10. Gently floss the area, irrigate, and evacuate thearea to ensure it is clean.

Before dismissing patients with fixed prosthetics,instruct them in procedures for cleaning therestorations.

REMOVABLE PARTIAL DENTURES

Some of the basic procedures for RPDs are thesame as FPDs, but require much more laboratory andappointment sittings. The following is a typicaltreatment plan you may be involved with if assistingwith the fabrication of an RPD. Each bullet representsa secheduled appointment.

Prosthetic examination and alginate impressionsfor study casts.

Mouth preparations for RPD framework andfinal impressions.

Framework try-in and adjustment.

Final impression of edentulous ridges forfabrication of the acrylic denture base, occlusalregistration, and denture tooth selection.

Figure 8-45.—Steps in cementing a permanent FPD.

Deliver RPD and make initial adjustments asnecessary.

Follow-up adjustment RPD appointments asrequired.

COMPLETE DENTURES

As with FPDs and RPDs, many of the basicprocedures are the same. With increased publicawareness on proper oral hygiene, personnel whorequire complete dentures are becoming a very smallpopulation of the armed services. The procedures thatyou will assist in are interocclusal registration, toothand tooth shade selection, tooth arrangement,impressions, and CD delivery.

STANDARD OPERATINGPROCEDURES PROSTHETICS

LABORATORY

As a chairside prosthetic assistant, you mustbecome familiar with the procedures of the prosthetic

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laboratory. If you do not know these procedures,patient cases can be lost or routed improperly. If youhave any questions about different procedures, ask thedentist or prosthetic technician.

CASE REQUESTS

Cases entering the laboratory are required to beaccompanied with a work authorization request (DDForm 2322). Requests are to be filled out withinstructions, signed by the requesting doctor, and mustindicate desired completion date. The case is thenentered into the Prosthetic Log and assigned a casenumber. This entry must be made by the persondelivering the case to the laboratory.

IMPRESSIONS

Before entering the laboratory ALL impressionsare to be sprayed with an approved disinfectant inaccordance with BUMEDINST. 6610.10, chapter 6,and covered with a plastic wrap (head rest covers workgreat). The laboratory technician is to be informed ofthe arrival of the impressions.

Alginate Impressions

Alginate impressions are to be placed into the trayholder at the plaster bench to prevent distortion of theimpression (a moist paper towel should be placed overthe impression to prevent dehydration of the material).

Final Impressions

This includes complete dentures, removablepartial dentures, crowns, and bridges. Theseimpressions are poured as prescribed by the doctor; ifno instructions are provided, they will be poured withstone mixed with liquid stone hardener.

Study Casts

Study casts are fabricated for diagnostic purposesand poured as prescribed by the doctor. If noinstructions are provided, they will be poured inplaster.

STONE OR PLASTER CASTS

Trim the casts once they are separated from thetray. Casts are trimmed to remove excess material byuse of the model trimmer.

You are required to don protective ear andeyewear.

Turn on water supply to desired flow.

Activate the model trimmer.

Trimmed casts will be rinsed, dried, and markedwith the patient's last name and case number (if spaceis available). The case will then be routed according tothe work authorization request.

CASES WHILE IN THE LABORATORY

Casts will be kept in case pans, protected in plastic(when available). Case pans will be labeled withpatient's name, doctor, date started, and prothesisbeing fabricated.

Pumice and polishing procedures for thefabrication of new protheses will not require specialprecatutions. Repairs, relines, rebases, or adjustmentsof any prosthesis that has had contact with patient'sbody fluids are considered old cases and will requireprecautions. Lathe instructions for pumice andpolishing are as follows:

The technician is required to ensure correctplacement of the protective shield is in the downposition before activating the lathe.

Pumice is to be replaced after each use.

Wheels/brushes used for pumice and polishingare to be removed from machine and sent toCSR.

Prostheses should be put into a glass beaker orziplock bag containing cleaning solution, thenplaced into ultrasonic.

Ultrasonic Cleaner

The prosthetic ultrasonic cleaning machine is thesame as the CSRs except that dental prostheses are runthrough. The following are guidelines for its use:

Ultrasonic to contain water approximately 1 to1-1/2 inches. Special solutions to be used inziplock bags or glass beakers.

General-purpose cleaner or stone and plasterremover solutions can be reused when used onnew cases. Once solution is used for an old case,the solution is to be discarded.

Stain and tarter solution is used for old cases andwill be used one time then discarded.

Once the ultrasonic cleaning procedure iscompleted, the prosthesis is then brushed and rinsedwith water. It is then bagged and replaced into theassigned case pan.

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Completed Cases EPA-registered disinfectant. Also disinfect pliers andother special instruments after each use, even if they donot come in contact with blood or saliva. An alternatemethod is immersing the instruments in anEPA-registered intermediate or high-level disinfectantsuch as iodophor or 2 percent glutaraldehyde.

The work authorization request will be closed outin the Prosthetic Log by entering the date ofcompletion. This is done by the delivering dentist orthe technician. The work authorization request will beretained in the laboratory for two years. The case panand its contents will be placed on the plaster bench forcleaning. Cleaning includes the emptying of usedmodels and the spraying down of the case pan.

GUIDELINES FOR INFECTIONCONTROL IN THE DENTAL

LABORATORY

When you are working in the prosthet icdepartment or the laboratory, infection control is still amajor concern. Follow BUMEDINST 6600.10, DentalInfection Control Program, for complete guidance andinstructions. Prostheses or impressions may carry amultitude of bacteria in dental plaque, blood, or saliva.To protect everyone from cross contamination andpossible infection, dental personnel must use propertechniques for disinfection of material before sendingit to the laboratory from the DTR and vice versa.

BARRIER CONTROL

Place barriers wherever possible to prevent crosscontamination. Establish a designated area in thedental laboratory where technicians disinfect allincoming and outgoing items.

DTR INFECTION CONTROL

Wipe contaminated shade guides, face-bows,a r t i c u l a t o r s , a n d a l c o h o l t o r c h e s w i t h a n

Instrument Sets

When possible, use trays to allow sterilization ordisinfection of multiple instruments.

Unit Dose Concept

Use o f the un i t dose concep t p reven t scontamination of bulk supplies. Dispense enough tocomplete the entire procedure when using such itemsas petroleum jelly, impression materials, waxes,pressure disclosing or indicator paste, disposablebrushes, and orthodontic brackets and wires.

Processing and Transfer to the Laboratory

When possible, rinse and disinfect impressions,prostheses, and intraoral devices before transfer to thelaboratory to reduce chances of cross contamination.If the integrity of the item or material is compromisedby this disinfection, a waiver should be requestedthrough the command on the item (for example,procelain-stained crown before bake). Place casts andprostheses in self-sealing plastic bags to preventcontact with adjacent materials, the shipping box,foam insulation, or paper work. Consider everythingreturned from a dental laboratory as contaminated.The receiving facility must disinfect these items.

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CHAPTER 9

DENTAL TREATMENT ROOM EMERGENCIES

INTRODUCTION

Medical emergencies can and do occur in dentalclinics. They can be life threatening as a result of amedical condition or an accident (e.g., chemicals orscrap amalgam getting in eyes). Most accidents arepreventable if you observe and follow safetyprocedures. All dental patients must wear approvedsafety glasses with side shields. Also, passing ofinstruments and medications over a patient’s face,should be avoided to prevent injuries. The dentalofficer will always be in charge of an emergency. As adental assistant, you must know how to react and treatthe injured until the medical department arrives andassumes responsibility. Since each command mayhave slightly different equipment and procedures, youshould become familiar with these emergencyprocedures as soon as possible.

PREVENTING MEDICALEMERGENCY SITUATIONS

The best means of handling medical emergenciesis to take every precaution to prevent them.Precautions taken in the dental treatment room orfacility include: close review of the Dental HealthQuestionnaire, checking a patient’s vital signs, andknowledge and use of emergency equipment.

VITAL SIGNS

The physical condition of a patient can bedetermined by checking the following vital signs: bodytemperature, pulse, blood pressure, and respiratory rate.

Body Temperature

An adult’s normal body temperature may range from97°F to 99°F (36.1°C to 37.2°C). A person with a bodytemperature above 99°F has a fever, and a person with abody temperature below 97°F has a subnormaltemperature. Most dental clinics commonly use anelectronic thermometer that displays body temperature asnumbers in a digital display. It uses a disposable plasticcover that goes over the temperature probe and is placedunder the tongue. Always discard the plastic cover after

each use. Follow the manufacturer’s instructions foruse and maintenance.

Pulse

As the heart pumps blood through the arteries, theyexpand and contract, producing a regular heart beat orpulsation. The number of beats per minute is the pulserate. For adults, a normal pulse rate ranges from 60 to80 beats per minute; for a child, it ranges from 80 to110 beats per minute.

Normal site for taking the pulse is the carotidartery, located on either side of the neck (fig. 9-1). Youshould always check the carotid pulse on the same sidethat you are on. Never reach across a patient’s larynx.To locate the carotid pulse, slide your index and middlefingers into the groove between the trachea and themuscles at the side of the neck where the carotid pulsecan be felt. Do not use your thumb because it has a

DTV2f901

Figure 9-1.—Locating the carotid pulse.

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pulse of its own and will confuse your counting. Todetermine the pulse, once you feel the artery beating,count the beats for 30 seconds, multiply by 2, and thenrecord the results.

If you notice any irregularity, take the patient’spulse again. This time, however, count the beats for afull minute. If the pulse is still irregular in rate orrhythm, inform the dental officer.

The other common site for taking the pulse is theradial artery on the thumb side of either wrist (fig. 9-2).If you are taking the pulse at the radial artery, have thepatient place his arm in a relaxed position on the arm ofthe dental chair. Lightly rest your index and middlefinger on the patient’s radial artery to determine pulse.

Blood Pressure

Blood pressure is the force that the blood exertsagainst the walls of the arteries as it flows through thearterial system.

The maximum blood pressure occurs when theheart contracts. This is referred to as the systolicpressure. Norma1 blood pressure range for thesystolic reading for an adult is 90 to 140 millimeters ofmercury (mm Hg).

The minimum blood pressure occurs when theheart relaxes. This is referred to as the diastolicpressure. Normal blood pressure range for thediastolic reading for an adult is 60 to 90 mm Hg.

Take the blood pressure of each patient over theage of 5 at the initial and annual examinations, or whendirected by the dentist. Record the results on the

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Figure 9-2.—Taking the radial pulse.

patient’s Dental Exam Form. An entry of 120/80 wouldindicate the systolic pressure is 120 mm Hg(millimeters of mercury) and the diastolic pressure is80 mm Hg.

Blood pressure is measured with a sphygmo-manometer and a stethoscope or an electronic unit thatprovides a digital reading. Follow manufacturers’instructions for use and maintenance of your particularequipment.

Respiration

Respiration is the act of inhaling and exhaling.One inhalation and one exhalation is a complete cycle.The respiration rate for an adult may range from 12 to15 cycles per minute; for a child the rate is 15 to 18cycles per minute; and for an infant the rate is 18 to 20cycles per minute.

Respiration can be controlled by the patient. Toobtain an accurate respiration rate without the patient’sknowledge, watch the chest rise and fall, and count therespirations.

EMERGENCY RESPONSE TEAM

Your command will have an emergency responseteam that is appointed by the commanding officer orbranch director. This team responds to all emergencieswhen called upon. It consists of at least one dentalofficer and two dental technicians. It is activated bythe front desk personnel and announced over theclinic’s loud speaker system. An example of this maybe as follows: attention in the clinic, code blue in dentaltreatment room five. The front desk personnel shouldrepeat this message twice. Your command instructionwill have specific guidelines for announcing theemergency.

When activated the appointed dental officer goesdirectly to the emergency and the techniciansappointed retrieve the medical emergency equipmentand bring it to the scene. A mobile crash cart isbrought to the emergency and will consist of anautomated external defibrillator and emergency drugs.A portable unit of oxygen is also brought. The oxygentank is an E size cylinder that provides approximately78 liters of oxygen per minute for one-half hour. Anextra cylinder should be standing by if needed. A clearoxygen mask or hand operated resuscitator will beattached to the oxygen unit.

Once the dental officer assesses the emergency, hemay direct a member of the team to notify the front

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desk to activate the medical clinic’s emergencyresponse team to take over the emergency. Dentalpersonnel should be standing by at the entrance wheremedical personnel will arrive in order to direct them tothe emergency.

Please note that not all dental commands have thesame procedures as described above. You must readyour own command’s instruction on emergencymedical procedures for your specific command.

BASIC LIFE SUPPORT

Respiratory failure and cardiac arrest occur when a

victim’s heart suddenly stops beating, causing the

blood to cease circulating.

A victim of respiratory and cardiac arrest mustreceive cardiopulmonary resuscitation (CPR) within 4to 6 minutes after the heart stops beating. You must beable to recognize what is wrong and provideimmediate emergency medical treatment includingbasic life support (BLS) until the medical departmentarrives. BLS is the attempt to restore lung and heartfunction. These procedures can be summarized interms of the ABC’s of basic life support. The primaryemphasis is placed on maintaining an open airway tocounter upper airway obstruction, restoring breathingto counter respiratory arrest, and restoring circulationby chest compressions to counter cardiac arrest.

MEDICAL EMERGENCY GUIDELINES

The guidelines for medical emergencies are as

follows:

Get organized

Remain calm

Take charge of the situation

Act quickly but efficiently

Get assistance from other staff personnel so theycan notify the emergency response team ifneeded

Make a preliminary assessment of the victim’scondition in the position you found him in ifpossible

Determine the foremost life-threateningcondition

Maintain treatment until qualified assistancearrives

CPR COURSE CERTIFICATIONS

There are three types of CPR courses, each relateddirectly to the curriculum:

Heartsaver course—teaches learners in one-rescuer CPR, management of foreign-body airwayobstruction, and the use of barrier devices forventilation.

Pediatric BLS course—teaches learners how toadminister CPR and first aid for choking infants andchildren.

Healthcare provider course—teaches healthcareprofessionals in one-rescuer CPR, management offoreign-body airway obstruction, two-rescuer CPR, theuse of barrier devices, and (optionally) the use of anautomated external defibrillator (AED).

All dentists, dental technicians, and auxiliarydental personnel must be certified in the healthcareprovider course for BLS if directly involved withpatient care.

RESUSCITATING DEVICES

Among the standard emergency equipment in theDTR is the hand-operated resuscitator (fig. 9-3), alsoreferred to as a bag-valve mask. It allows the operatorto rescue breathe for the patient without mouth-to-mouth contact. This device consists of a face mask andan inflating bag joined by a valve. A connector at theend of the bag allows the resuscitator to be connectedto an oxygen supply. The mask is clear so the operatorcan see the patient’s mouth in case regurgitationoccurs. If this happens, gently turn the patient’s entirebody on the right side, wipe out the mouth, return thebody to its original position, and continue to rescuebreathing with the hand-operated resuscitator.

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Figure 9-3.—Pediatric and adult resuscitators.

The resuscitator is very difficult to use. Theprimary problem is keeping an effective seal betweenthe patient’s face and the mask. Due to this, it isrecommended that the resuscitator be used only whenthere are two rescuers available to operate theresuscitator. One to maintain an air tight seal while theother rescuer squeezes the bag.

USE OF OXYGEN SUPPLY

At the dentist’s direction you may hook up theresuscitator to an oxygen supply. Oxygen tanks arealways painted green. Attach the oxygen hose from theoxygen bottle to the connector on the end of theresuscitator.

On the top of the oxygen tank is the cylinder valve.A yoke is used to attach the liter gauge and pressuregauge to the oxygen tank. When directed, turn theoxygen supply cylinder valve counterclockwise (fig.9-4) until it is completely open. Next, turn the regulatorcontrol adjust handle clockwise until the proper flowrate in liters per minute is established on the litergauge. The normal flow rate is 6 liters per minute.Once the oxygen is turned on, place the mask over thevictim’s nose and mouth. Pump the inflating bag onceevery 5 seconds for an adult, once every 4 seconds for achild, and once every 3 seconds for an infant.

NOTE: Oxygen in the atmosphere occurs in anapproximate concentration of 21%, commercialoxygen is pure 100% oxygen.

Safety Precautions

Combustible materials must never come incontact with the oxygen cylinder

No smoking in any area where there are oxygencylinders or where oxygen is being administered

Use only a properly fitting regulator valve

Close all valves when the cylinder is not in use

Secure cylinder(s) upright in a proper storagerack or carrier for transportation

Always stand to the side of the cylinder

OTHER MEDICAL EMERGENCIES

Other medical emergencies may occur in thedental operatory, X-ray, or even the reception area.You must always be prepared to recognize and treatthese emergencies.

ANGINA PECTORIS

Angina pectoris, also known as angina, occurswhen there is a narrowing of the coronary arteries withdecreased blood flow to the heart. The constriction ofblood flow may cause the patient to experience similarsigns associated with a heart attack such as painradiating in the arms and chest. Some of the majorcauses are as follows:

Extreme physical exertion

Emotional stress

Signs and Symptoms

Pain from under the sternum

Heavy feeling or pressure on the chest

Burning feeling between the shoulder blades

Cyanosis, shortness of breath

Anxiety

Treatment

Place patient in a 45-degree angle (sitting up).

Administer 100 percent oxygen and onenitroglycerin tablet sublinually (beneath thetongue).

NOTE

minutes until relief is obtained. If the pain persists

One additional sublingual nitroglycerin tablet ortranlingual spray dose may be repeated every five

after a total of three tablets of spray doses in a 15-minute period, the patient should be brought to medicalfor an evaluation by a medical officer. Also check tosee if the patient is wearing a transdermal form ofnitroglycerin. If they are, a second dose is not usuallyrecommended unless prescribed by a medical or dentalofficer.

SHOCK

Shock is a syndrome (a collection of symptoms)that results from a rapid decrease in blood circulationdue to a loss of blood and/or vascular collapse, andfrom the body’s attempt to compensate for thesedecreases. Some major causes of shock are as follows:

Allergic reactions

Severe or extensive injuries

Bites or stings from poisonous snakes or insects

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Figure 9-4.—Turning on cylinder valve.

Severe pain or burns

Loss of blood

Digestion of poisons

Exposure to extreme heat or cold

Electrical shock

Emotional stress

Gas poisoning

Certain illnesses

Signs and Symptoms

Restlessness, anxiety, weakness, anxious or dull

expression, and disorientation

Weak, rapid pulse

Shallow, irregular breathing

Vacant, dull eyes with dilated pupils

Treatment

Activate clinic’s emergency response team

Lay the victim down

Elevate the feet

Keep victim warm

Keep victim calm

Maintain an open airway

SYNCOPE (FAINTING)

Syncope is a self-correcting, temporary form ofshock. Usually, the serious problems related tosyncope are injuries that occur when falling down fromthe temporary loss of consciousness. Fainting may becaused by stressful situations. Dental patients who

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experience this may tell you they feel weak and dizzywhile getting out of the dental chair after a procedure.If a patient is still conscious, have him sit back in thedental chair and place him in the Trendelenburg’sposition (fig. 9-5). Place the patient in a positionslightly lower than supine with feet elevated slightlyabove the head.

Signs and Symptoms

Weakness, dizziness, black spots in vision

Pale face, blue lips

Cold perspiration

Rapid, weak pulse

Shallow breathing

Treatment

Activate clinic’s emergency response team ifdeemed needed by the dental officer

Lay victim down

Elevate feet (Trendelenburg style)

Loosen tight clothing

Maintain an open airway

Use an ammonia ampule

ANAPHYLACTIC SHOCK

Anaphylactic shock is the result of a severeallergic reaction. It is a life-threatening emergency andusually occurs within seconds after the victim isexposed.

Signs and Symptoms

Itching and burning of the skin with flushing

Cyanosis around the lips

Swelling of the face and tongue

Paleness

Swelling of the blood vessels just underneath the

skin

Weak, rapid pulse

Low blood pressure

Dizziness

Restlessness

Painful, squeezing sensation in the chest

Difficulty breathing

Respiratory wheezing

Nausea, vomiting

Abdominal cramps

Diarrhea

Treatment

Activate clinic’s emergency response team.Provide treatment according to BLS procedures(including CPR).

HYPOGLYCEMIA

Hypoglycemia is caused by low blood sugar in thebody. Anyone can be affected by hypoglycemia. It canoccur if a victim has not eaten for a long period of time,

Figure 9-5.—Trendelenburg’s position.

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has overexerted themselves (such as overexercising),or has vomited. A victim can become unconscious—often referred to as insulin shock.

Signs and Symptoms

Extreme weakness

Pale, moist skin

Normal or shallow breathing

Normal blood pressure

Normal or rapid pulse

Double vision

Apathy and irritability

Drooling

Tingling and numbness in fingers or feet

Dizziness

Headaches

Fainting

Profuse sweating

Eventual unconsciousness and coma

Treatment

If severe, or victim is unconscious, activate theclinic’s emergency response team

Never give an unconscious victim oral liquids

If the victim is conscious, give the victim a drinkof (soda or presweetened juice) or a piece ofcandy containing sugar

If the victim is unconscious, place a sugar cubeunder the tongue

Pounding feeling of

Tired or weak

Feeling of impending doom

Rapid breathing

Fainting

the heart (tachycardia)

Tightness or a lump in the throat

Shortness of breath

Tingling of the hands, feet, or area around themouth

Hyperventilation is an abnormal respiratorycondition where the victim overbreathes or breathestoo rapidly. This condition usually occurs whenapprehensive patients breathe more rapidly inresponse to their own anxiety.

Signs and Symptoms

Treatment

Calm the victim and provide reassurance

Try to get the victim to slow his breathing down

Place a paper bag over the victim’s mouth andnose

ASTHMA ATTACKS

Anxiety, nervousness, fear

Dizziness or lightheadedness

Blurred vision

Dryness or bitterness of the mouth

Asthma attacks interfere with normal breathingand occur when the airways constrict making thepatient produce a wheezing sound as he or shebreathes. A patient who has been diagnosed as havingasthma, will usually carry an inhaler containingmedication to treat there mild attacks.

Signs and Symptoms

Coughing spasmodically and unproductively

Cyanosis

breathe

Difficulty in breathing

Wheezing, gasping sounds when attempting to

HYPERVENTILATIONTreatment

Sit the victim down

Calm and reassure the victim

If the victim carries medication, help him takethe medication

Activate clinic’s emergency response team ifneeded

SEIZURES

In a conscious, healthy individual, muscularmovements are usually smooth and coordinated. If the

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normal functions of the brain are upset by injury,infection, or disease, the electrical activity of the braincan become irregular. This irregularity can bring aboutsudden uncontrolled muscular contractions known asseizures.

Signs and Symptoms

Body becomes rigid and then jerks violently

Jaw clamped shut

Foaming at the mouth

Loss of consciousnes

Treatment

Activate clinic’s emergency response team

Lay the victim down

Loosen or remove tight clothing

Turn victim on her side with the head extendedand face turned slightly downward

Maintain airway

Do not restrain the victim unless she is inimmediate danger

After the seizure is over, reassure and reorient

the victim and allow her to rest

DUTIES DURING ADMINISTRATIONOF MEDICATION

After the patient has been anesthetized orpremeditated with a drug, you should observe thepatient to ensure that the drug is working and bewatching for signs of an adverse reaction. Never leavea pat ient alone that has be anesthet ized orpremeditated with a drug.

SIGNS AND SYMPTOMS OF ADVERSEREACTION

Raised, hive-like patches with severe itching

Wheezing, difficulty in breathing

Nausea, vomiting

TREATMENT

if necessary administer basic life support andactivate clinic’s emergency response team immediately.

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CHAPTER 10

FORENSIC DENTISTRY

INTRODUCTION

Forensic dentistry may be defined as that branchof forensic medicine that applies dental knowledge tocivil and criminal problems. The military simplyexpands this definition to include the unique needs ofthe military services. While it is true that our primarymission is to support requests for aid in forensic dentalidentification, you must understand that dentalidentification is only one of a number of major areasin forensic dentis try. These include: dentalidentification, bite mark analysis, human abuse andneglect, dental malpractice and negligence, and dentalanthropology and archaeology.

As a basic dental assistant, your primary dutieswill be assisting dental officers and civilian dentistswith the dental identification section in forensicdentistry when directed. The other major areas inforensic dentistry will not be covered in this bookbecause they pertain mainly to dental officers anddentists.

PURPOSE

The primary reason we in the Navy have beendirected to establish a forensic dental identification(ID) capability is to assure our ability to assist in the IDof human remains. In most cases this meansidentifying members of the Armed Forces, butoccasionally it may include civilians. We are tasked todo this to meet both the civilian needs and the uniquemilitary needs for positive ID of individuals. The firstfour of these needs are common to both the militaryand civilian communities and include estate,insurance, legal, and psychological considerations.The last two needs are military considerations andinclude manpower and intelligence needs.

ESTATE

Positive ID is necessary to allow probate of the lastwill and testament and transfer of any inheritance tothe deceased's next of kin. Without positive ID, thisprocess could be delayed until the person is declaredlegally dead, or up to 7 years.

INSURANCE

Positive ID also is necessary to allow survivors toproperly claim any life insurance held by the victim.Again, if a positive ID is not accomplished, thepayment of insurance to the beneficiaries could bedelayed for years. This would defeat the purpose forbuying the policy in the first place and could deny anysurvivors the funds needed to adjust to the loss of theprovider's income.

LEGAL

A less common but important consideration is thepossibility of legal action such as malpractice orwrongful death litigation. Obviously, it would be verydifficult, if not impossible, to prove wrongful death ina court of law if one cannot prove that an individual isdead. This would not only eliminate any possibility forcompensation for loss of a loved one, but also couldaffect the legal handling of the deceased's estate as wellas payment of any life insurance benefits.

PSYCHOLOGICAL

The last of the common needs is the psychologicalaspect of an individual's death. The loss of a loved oneis frequently psychologically devastating to those leftbehind. In fact, many persons are not able to accept thedeath of their child, parent, or spouse until long afterthe occasion. Not knowing positively their loved oneis dead complicates this process leading to false hopesand preventing the survivors from getting on with theirlives. A graphic example of this was the tremendousagony experienced by the next of kin of our Vietnammissing in action.

MANPOWER

Simply stated, you need to know who thecausalities are so you can rapidly replace them. If wedo not know who the Sailors are, it will be impossibleto replace them with persons of similar training andskills in their areas of expertise to restore full combatreadiness.

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INTELLIGENCE

You also must know the location and condition ofour personnel familiar with sensitive operationalinformation. If a Sailor who knows the details of anupcoming operation is missing, you need to knowwhether he is wounded, dead, or captured, and if theoperation plans have been compromised.

OTHER METHODS OF IDENTIFICATION

Now that we have established the purpose forforensic dental identification and explained why wehave been tasked to do so, we need to look at whydental techniques have become so important inforensic identification operations. To do this we needto look at some of the other different methods offorensic identification. Various methods of ID havebeen used depending on the individual situation.

Body Characteristics

Many body characteristics can be used to identifyan individual. Recognition includes using visual,scars, deformities, and tattoos methodologies.

Visual recognition—this is the most commonmethod. It is reserved for instances in which no real

doubt exists about the identity of the individual anddeath did not occur under unusual circumstances. Itsdrawbacks occur when changes in appearance becauseof illness, fire, water immersion, or decompositionmake ID quite difficult. Figures 10-1 and 10-2 showsoft tissue trauma from fire and water. Visualrecognition, therefore, is considered an unreliablemeans of identification in medico-legal deathinvestigation and not usually acceptable as positiveproof on the identity of the deceased individual.

Scars—this method is useful in some cases.Surgical scars are probably the most commonly foundbut are of the least value since they are seldomdistinctive. Like visual recognition, scars can change orbe destroyed by the same processes affecting visualrecognition.

Deformit ies —may be either soft tissuealterations or because of bony abnormalities.Radiographs of the deformity on file in the medicalrecord can be useful in the ID process. The bonydeformity must be significantly distinctive, however, tobe of value as a means of ID.

Tattoos —can assist in the identificationprocess. Figure 10-3 shows a tattoo on an arm. Multipletattoos would increase the likelihood of positive

Figure 10-1.Charred remains from fire.

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Figure 10-2.—Remains from immersion in water for two weeks.

identification. Again tattoos are soft tissue evidence assist in establishing the identity of the individual.and therefore are prone to easy destruction by Drivers' licenses, credit cards, ID cards, ID badges, andenvironmental effect. For many reasons, tattoos should passports are just a few such items. In the military, dogbe used only as a secondary means to a positive ID. tags are used specifically for this purpose. Other

Personal Effectsexamples of personnel effects that may be helpful inestablishing an identity include name tags sewn intoclothing, distinctive jewelry, inscribed jewelry, andfamily photographs. Personal effects, however, are the

Personal effects may include anything that isfound on the body of the deceased that can be used to

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Figure 10-3.—Tattoo on an arm.

least reliable means of establishing an identity. Theyare not a physical part of the body, and, therefore, theymay easily be transferred from one individual toanother. In addition, lost or stolen items, and jewelryin particular, are very likely to be found in thepossession of an individual other than its owner.Falsified documents may be found improperlyidentifying an individual as someone else. In mostinstances, the identity established by the personaleffects will prove to be the actual identity of thedeceased, but this must still be verified by a moreobjective, definitive means of ID.

Skeletal Remains

Identification by skeletal remains may be anexcellent means to identify an unknown individual. Insome cases, it can provide positive proof of identitythat is acceptable in a court of law. Identification byskeletal remains requires matching of postmortemradiographs with radiographs that were taken beforedeath. Features that can be used for ID by skeletalremains would include healed fracture sites,pathologic lesions, and medical hardware.

The main problem with ID by skeletal remains isthe fact too few individuals in the general populationhave such characteristics. This makes it difficult torely on as a routine method of ID of an unknown body.

Fingerprints

Of all the methods of ID, fingerprints are probablythe best known. Fingerprints are an excellent meansof positive ID. Figure 10-4 demonstrates a finger-printing technique used by the FBI. Many individualswill argue that fingerprint ID is the most definitivemeans of identifying an unknown set of humanremains, and it is generally accepted that no twoindividuals have the same set of fingerprints.Fingerprint ID, therefore, is always acceptable in acourt of law.

DNA Analysis

DNA analysis, also known as DNA fingerprinting,is a fairly new technology that may replace dentalidentification and fingerprint identification as the mostdefinitive means of identifying unknown remains. Itwill be fully implemented when an adequate databaseof DNA specimens can be established.

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Figure 10-4.—Fingerprinting

DENTAL IDENTIFICATION

Dental ID, like fingerprint ID, is a definitive meansof positive identification of unknown human remains.It also is routinely acceptable as evidence in court. Ithas several significant advantages, and only a fewdisadvantages when compared with fingerprintidentification. The bulk of the remaining chapter willcenter on dental ID.

WHY DENTAL IDENTIFICATION WORKS

Dental evidence tends to survive much better thandoes soft tissue evidence such as facial characteristicsor fingerprints. Teeth are calcified structures and arethe hardest substance in the human body, even harderthan bone. Because they are calcified, they areresistant to the environmental effects that destroy softtissue evidence. Thus teeth are not destroyed byimmersion in water, by desiccation (drying up), or bydecomposition. Even in cases of skeletalization ofremains, teeth are available for ID purposes. Inaddition, teeth are relatively resistant to destruction byfire. However, teeth can be destroyed in rare instancesby heat if the temperatures are greater than 1000°F andthe teeth are unprotected by the soft tissues of thecheeks and lips. Figure 10-5 shows intact dentition of a

charred mandible. Teeth are further protected by thesoft tissue mass of the tongue. The roots of the teeth areencased in the alveolar bone, providing an additionallayer of protection. Therefore, even in fires wheretemperatures approach 1600°F, teeth are ordinarilyfound intact within the oral cavity and can be used forID when all other means have been destroyed. Inaddition to the teeth, the materials used for dentalrestorations are also resistant to destruction by theenvironment, even more so than the natural teeththemselves. Gold alloys, as shown in figure 10-6,fused porcelain, synthetic porcelain, and porcelaindenture teeth all will withstand temperaturesexceeding 1600°F. Silver amalgam, the mostcommonly used restorative material, will resisttemperatures up to 1600°F.

Large Number of Potential Points ofComparison

The human dentition is composed of 32 teeth, eachof which may be restored, unrestored, or missing.When restored, any of the 5 different surfaces may beinvolved in the restoration. The number of potentiallydifferent dental chartings, considering even onerestorative material, is astronomically large (1 x 1048).In addition to restorations, the tooth crown form, root

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Figure 10-5.—Charred teeth.

Figure 10-6.—Gold fixed partial denture from a fire.

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canal, and root form provide numerous other potentialpoints of comparison that make each set of teethunique. Therefore, it can be said with completeconfidence that, given sufficient data, no two sets ofteeth are identical.

Antemortem Database

A decided advantage of dental ID over fingerprintID is the relatively comprehensive nature of theantemortem database. An extremely high percentageof the general population has visited the dentist at sometime in their life. Dentists routinely create dentalrecords for these patients that detail the antemortem(before death) dental condition. These records areoften maintained for long periods of time. Mostimportantly, dental radiographs are generated onalmost every patient. Radiographs are hard evidencethat is not subject to human error to the same extent thata written dental record might be. The radiographs alsoprovide multiple additional potential points ofcomparison for establishing ID. With adequate dentalrecords available to the forensic dentist, nearly 100%of unknown remains can be identified.

PROBLEMS IN DENTALIDENTIFICATION

The dentist and you, the Dental Technician, mayencounter many problems with dental ID. Theseproblems can waste numerous hours or days before thefinal determination of ID.

Illegible Dental Records

Because in many cases the dental records arehandwritten, the task of determining what treatmenthas been provided can be quite difficult.

Inadequate Dental Radiographs

Radiographs may not be found useful forcomparison purposes for a variety of reasons. Mostoften this is because of poor quality of the radiographobscuring the features necessary for comparison. Itmay also be because of a lack of positioning of theradiograph or absence of a date on the radiograph.

Lack of Adequate Charting

Many civilian dentists do not record the status ofthe dentition at the first appointment as required in theNavy. Pre-existing restorations, therefore, may not be

Dentists might use multiple systems to record thetreatment provided for a patient and to indicate whichtooth was treated. Unless the forensic dental team isfamiliar with every possible charting and numberingsystem, a dental record may be unintelligible despitebeing legible. Luckily, most of the civilian and Navydentists use a single system for charting andnumbering teeth in the United States.

Changes in Dentition

Teeth are not fixed in the jaws. Small changes inposition are constantly occurring in addition to thenormal functional wear produced by chewing. Thesechanges are not distinct over a short period of time, butover an extended time period these small changes canaccumulate to produce significant differences.

Human Error

No matter how conscientious and persistent adentist or Dental Technician might be about theaccuracy of their dental records, errors in the writtenrecord will occur on occasion. This can causediscrepancies in the comparison and problems inestablishing the ID.

PRINCIPLES OF DENTALIDENTIFICATION

The principles of dental ID are identical to thoseused in any other ID method. The postmortem (afterdeath) remains are examined and documented, then theantemortem records are obtained and reviewed, andfinally the two are compared to establish similaritiesand discrepancies. In evaluating the comparison, theforensic dental team looks first at discrepancies.Discrepancies are more important than similaritiessince a single discrepancy can negate a whole list ofsimilarities. It is important for the dental team toconsider the source of the discrepancy. If thediscrepancy is found in the written dental record, itmay be possible to explain it on the basis of humanerror. However, if the discrepancy is in a radiographiccomparison, it is extremely difficult to ignore.Discrepancies may be classified into two broadcategories, relative and absolute.

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documented in the dental record, leading to confusionin the final analysis.

Lack of Uniformity of Charting andNumbering Systems

Relative Discrepancies

These represent differences between the antemortemand the postmortem dental exam findings that can beexplained by continued dental treatment. For example,an unrestored tooth may have been restored in the timeinterval between the last dental record entry and thedeath of the individual. Or, a small restoration may beenlarged because of additional decay. In any case,these discrepancies do not necessarily negate anidentification if there are enough similarities in theremaining evidence.

Absolute Inconsistencies

These represent differences between the antemortemrecords and the postmortem exam findings that arephysically impossible and prove the remains cannot bethose of the individual under consideration. Forexample, an unrestored tooth is found in the unknownremains. On examination of the antemortem records,however, the radiographs reveal the tooth in questionhad previously been restored. Since natural toothstructure can never be replaced once it has beenrestored, this finding would verify that the remainswere not of those of the suspect individual.

Once discrepancies have been examined, thedental team will compare the number and degree of anysimilarities found in comparing the antemortem andpostmortem records. No minimum number ofsimilarities are required or accepted for positive ID. Inmany cases a judgment decision on the part of theexaminer may be required regarding the certificationof the ID.

RADIOGRAPHIC COMPARISONS

At some point in the ID process, as shown in figure10-7, the dental team will use dental radiographs andcompare with the dental remains of the deceased.There are four categories in radiographic comparison.

Exact Match

The postmortem radiographs show a restorationthat in every respect is identical to a restoration in thesame tooth in the antemortem radiographs as shown infigure 10-8. In some cases, the radiographs may be laidon top of each other to compare. Multiple distinctivepoints of comparison are normally documentable in asingle restoration.

Figure 10-7.—Forensic dental team comparing dental remains with radiographs.

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Figure 10-8.—Postmortem and antemortem exact match periapical X-ray.

Similarity which the antemortem and postmortem radiographswere exposed.

The restoration in the postmortem radiographs isnot identical to the restoration seen in the ante-mortem radiograph. The restorations occupy thesame position in the tooth and many similarities inform are present, but there is no exact match.Similarities are caused by differences in the angulation at

Relative Discrepancy

A significant difference exists between therestorations in the antemortem and postmortemradiographs. Little or no similarity can be found

10-9

between them. However, the difference is explainable

by continued treatment and no absolute inconsistency

is present.

Unidentified

Absolute Inconsistency

A significant difference between restorations or

teeth in the antemortem and postmortem radiographs

are presented that are not explainable by continued

treatment. In fact, they are found to represent an

impossibility in treatment.

CLASSIFICATION OF THE DENTALIDENTIFICATION

Classification is the last and most important step in

the dental ID process. Five classifications can be used

to establish identity.

Positive Identification

The forensic dentist is positive they havedetermined the identity of the individual. Radio-graphic comparisons have been used in the ID process.

Positive Identification byCharting Only

The forensic dentist feels confident in identifying

the individual, but radiographic comparisons have not

been used in the ID process. The ID is based solely on

the written dental record. This category of ID leaves

open the possibility that errors in the written dental

record may be present and could affect the ID process.

Consistent With

A good probability is the remains are those of the

suspect individual. However, the findings are such

that the forensic dentist is not confident enough to

certify the remains. In this situation there is usually a

deficiency in either the antemortem or postmortem

evidence with which to make a comparison. It may

also be because of a lack of similarities or because of

the presence of too many discrepancies.

Exclusion

Absolute inconsistencies are present. The remains

cannot be those of the suspect individual.

No sufficient evidence exists to determine theidentity of the remains. While it could possibly be thesuspect individual, it could just as easily not be theindividual. Additional information, either antemortemor postmortem, is required before an identification canbe established.

MANAGEMENT OF MASS CASUALTYOPERATIONS

Although each mass casualty operation is uniquein many ways, some basic principles are common to allsuch missions. First and foremost is recognition thatthese operations require a team effort by allparticipating parties. Figure 10-9 shows the forensicteam receiving a victim to start the ID process.

While many specialty areas may be represented,all must work together and exchange information if theoperation is to be a success. For our purposes, we willdivide the participants into members of command/support elements or members of identificationelements. The command/support elements consist ofthe following:

Commander Facilities support

Public affairs

Communications Storage/handling

Regis t a r Mortuary affairs

Data processing

Security

Graves registration

Recovery/transportation

The identification elements consist of the following:

In processing

Photographic

Personal effects

Finger/foot print

Medical radiology

Dental

Medical exam/lab

Anthropology

Facial reconstruction

THE DENTAL TEAM IN MASSCASUALTY OPERATIONS

Like the other elements of the operation, thedifferent sections of the dental team work togetherwith a common goal. The basic steps in forensic dentalidentification are (1) postmortem examination and

10-10

charting, (2) antemortem record acquisition and recordreconstruction, and (3) antemortem and postmortemrecord comparison. The dental elements of the teamare described next.

DENTAL TEAM LEADER

The dental team leader (dental officer) performsthe same tasks as the operations chief, only withinthe confines of the dental team. He brings backinformation to the dental sections and takes inform-ation to the operations commander and other membersof the ID operation.

DENTAL REGISTRAR

The registrar is one of the most important membersof the dental element because he must control andprotect all dental evidence coming into and going outof the dental area. He logs in and out all evidence,antemortem and postmortem, keeps track of workloadfigures (IDs per day, X-rays taken, photographs made,etc.), and coordinates with other areas of the operationto ensure that all potentially valuable sources of dentalinformation are made available for review by the

Figure 10-9.—Receiving a victim.

dental officer or dentist. Figure 10-10 shows a dentalregistrar updating a forensic tracking board. He makesparticular efforts to coordinate with personal effects,medical radiology, and medical examination sectionsand keeps the operations registrar updated withinformation the dental section needs. He alsomaintains and updates the dental exclusion matrix foruse at the close of the operation.

ORAL SURGERY

The surgeon's primary job, if needed, is to exposemaxilla and mandible so that the postmortemexamination team can examine and chart the dentalarches. Figure 10-11 shows a maxilla and mandiblethat have been completely removed from a casualty.This is accomplished by removing tissue from aroundthe oral cavity to expose the teeth, sectioning the ramusof the mandible and the pterygoid muscle to allow therelease of the lower jaw. Also, making an incision inthe floor of the mouth will release the mylohyoidmuscle to ensure an accurate anatomical placement ofthe dental films. This is made by the Dental Technicianwho will take radiographs of the appropriate areas.

10-11

Figure 10-10.—Dental registrar.

DENTAL RADIOLOGY

Postmortem dental radiology plays a critical rolein the process of identifying unknown human remains.The procedures used are basically identical to thosethat would be performed on a living patient, withcertain adaptations necessary to each specificsituation. The actual exposure of postmortemradiographs poses some special problems that must berecognized and considered to ensure the production ofadequate, useful radiographs for comparison with theantemortem dental records. These problems will varydepending on the number of remains to be identified,the condition of those remains, the completeness of thedental structures recovered, and the availability ofantemortem dental records. In general, the smaller thetotal number of remains to be processed, the fewerproblems with postmortem radiology. As the numberof remains increases, the problems encountered inperforming postmortem radiology will increase bothin total number and complexity.

Access

Access to dental structures for placement andexposing of the radiographs is entirely determined bythe condition of the remains. Normally no problems

are associated with skeletalized remains. The lack ofsoft tissue allows easy visualization for placement of

film and angulation. Positioning of the tubehead canalso be readily determined and adjusted as needed.The same is true for fragmented remains, which areeasily positioned against the X-ray film on a flatsurface, as shown in figure 10-12.

Problems with access to dental structures arisemost commonly with intact full body remains. This isparticularly true if it is a recent death and rigor mortis(stiffing of a dead body) is still present. Opening the

jaws more than just a few millimeters can beexceedingly difficult in the presence of rigor mortis.Problems with access are also routinely encountered inindividuals killed by fire, because of the loss offlexibility of the muscle fibers as they are cooked in theextreme heat. Drowning victims will also presentproblems with access to the dentition. If the individualremained in the water for a prolonged period of time,the soft tissues around the teeth begin to swell withfluid and thereby obstruct accurate film placement.When access to the dentition for postmortem dentalradiology is a problem, the dental officer will be able toassist you with proper access.

10-12

Figure 10-11.—Exposed maxilla and mandible.

Equipment

In small operations with minimal number of

remains to be processed, equipment is not a major

consideration. However, as the number of remains

increases, the availability of equipment becomes a

major determining factor in the efficiency of the dentalId section. In situations where hundreds of remains

require ID, you should have as many X-ray machines

available as possible to speed up the initial processing

of the remains. Postmortem radiographs are obtained

will normally require approximately 20 minutes toexpose a complete series of postmortem radiographs.Therefore, a maximum of 3 sets of remains per hourcan be processed with a single X-ray machine. Careful

The forensic X-ray section must realize thatexposure of postmortem dental radiographs is the timelimiting step for the dental ID section as a whole. It

from regular floor-mounted, mobile endodontic, andportable military field types of dental X-ray units.

Exposure of Postmortem Radiographs

10-13

Figure 10-12.—Positioning dental fragment on X-ray film for exposure.

planning is required to prevent confusion in the flowand tracking of the remains as they are processed.

The dental radiology section's job is to get, asnearly as possible, a full mouth series of periapicalradiographs. On occasion, the forensic dentist mayrequest occlusal and lateral jaw films. The propertechnique to use is to expose of the films in the properanatomical orientation to prevent overlap, shorting, orelongation of exposed dental films. This is necessarybecause the postmortem films will be compared withthe antemortem films that were exposed on a livepatient using appropriate anatomical placement andangulation. Always expose a full mouth series usingduplicate film packets even if areas appear edentulousor teeth are missing, fractured, or avulsed. Shootdifferent films at several angles and take care to exposeall fragments in their proper anatomical orientation. Itmay not always be easy to take X-rays of teeth becausepostmortem dental remains may be fractured. Thefollowing supplies may be needed to assist you inexposing radiographs: hemostats, gauze, clay, andrope wax.

Developing

Any X-ray developer can be used to processradiographs. The use of a daytime loader is

recommended to speed up the process. When multipleremains are being processed at the same time, thefollowing procedures are normally prescribed.

The entire series of postmortem radiographs isexposed before any has been developed.

The series is placed into a labeled carryingcontainer for transport to the developing area.

Each series is developed at a single developingsite or machine. Films from one series are neverseparated from one another for developing.

Mounting

In forensic dental operations, it is not importantwhich method is used for mounting periapical andbitewing X-rays, as long as the method selected isuniform. The raised dot on the film can be facing in orout. All postmortem radiographs should be mounted inthe same manner so there will be no confusion by theexaminers as to which side is which. The policy shouldbe well publicized so that everyone working in thedental ID section, not just those in the dental radiologysubsection, are aware of the standard.

FILM ACCOUNTABILITY.—One primaryarea of concern is the ability to determine, at any point

10-14

in time, if a film is missing from the film mount. Thismight occur because of its falling out of the mount orbecause an examiner has purposefully removed it forsome reason. When dental evidence is incomplete anda complete series of postmortem radiographs has notbeen taken, there are two methods by which theexaminers know for sure what films are available fortheir use. The first, and best method, is to fill all holesin the mount with undeveloped, unexposed film onceall films from a set of remains are developed. Anexaminer who picks up a mount will immediatelynotice the green, opaque films in the mount and realizethat no radiograph is available for this particular area.If an empty space is present in any of the mountingslots, the examiner immediately knows that a film wastaken out of this site. The second method is to maintaina written inventory list of postmortem films exposedon each set of remains.

ELIMINATION OF ERRORS. —A routinemounting procedure is quite useful and involves takingthe following actions:

Have one viewbox per developer and co-locatethem so that loss of films in transport from developer toviewbox is not possible.

Use viewboxes that can be laid flat to preventdropping of films.

Orient all dots in the correct position.

Orient the entire series as it will appear in the

mount before actually mounting any films.

Remember whatever is in the center of the film

determines its position in the mount.

Have all series reviewed by a dental officer or a

dentist at the postmortem examination station for

correctness in mounting.

DENTAL POSTMORTEM EXAMINATION

The postmortem examination team you may be onis responsible for examining and charting the dentalremains to include the presence or absence of teeth,restorations, pathology, and any other feature thatmight be useful in the ID process. Figure 10-13 showsa forensic dental examination of a casualty.

The process starts with gentle cleaning of thedental remains with a tooth brush using sodiumhypochlorite (bleach) and hydrogen peroxide.Remember that incinerated (burnt) teeth are brittle andwill shatter if not handled carefully. Next, a teamprocess including either a team of three dentists or ateam of two dentists and a dental hygienist or a DentalTechnician, chart all dental evidence on a postmortemdental record form. Figure 10-14 is an example of acompleted postmortem dental record form.

Figure 10-13.—Forensic dental examination.

10-15

Figure 10-14.—Completed postmortem dental record form.

10-16

The entire dental team must agree to be consistentin charting methods. This is a slow process and muchattention must be paid to details. Remember to checkand double check each step. The team will decidewhich charting system they will use. The differentbranches of the service and civilian dentists all usedifferent charting systems and abbreviations. TheManual of the Medical Department, chapter 6,desc r ibes the Navy ' s cha r t ing sys tem andabbreviations used to complete all dental informationfor the different forms used in forensic dentistry. Otherdental abbreviations used for charting, such as theComputer Assisted Postmortem Identification, may beused and will be covered later in this chapter underComputer Support. The use of a fiberoptic light isinvaluable in the examination process. The examinerbegins by evaluating tooth #1 and associatedradiographs. The second dentist on the examinationteam evaluates tooth #1 and confirms the findings ofthe first dentist. The recorder charts the findings oftooth #1 and all three members confirm the charting.Tooth #2 is examined and the process is repeated untilall 32 teeth have been charted. The approach isredundant, but errors are corrected as they are made.Charting should be done in pen, not pencil. Findings to

be recorded during the postmortem examination are asfollows:

Dental restorations

Missing teeth

Prosthetic appliances

Pathology

Unique anatomy

Age estimate

References to possible gender and racial group

Teeth missing because of the trauma of the mishapshould be specifically noted to avoid confusion overextracted or congenitally missing teeth. A prostho-dontist should be available to examine and describedental prosthetic appliances. In some cases, theappliance may have been specifically marked foridentification as shown in figure 10-15. It is wise tosolicit from the victim’s family study models or extraprosthetic appliances that may be available. Suchevidence is important in providing antemortem dataregarding ridge shape/size, rugae, and general oralanatomy. The antemortem dental record will becovered next.

Figure 10-15.—Maxillary denture with SSN embedded in acrylic.

10-17

ANTEMORTEM DENTAL EXAMINATION

Another major section in forensic dentistryinvolves the antemortem dental record examination.Dentists, hygienists, and Dental Technicians caneffectively operate this section. The task of thissection will always be the most difficult in the entireforensic dentistry arena. They will be required todetermine who was involved in the disaster, locate andprocure all military or civilian dental records andradiographs, arrange for the delivery of thesematerials, and undertake the process of developing acomposite antemortem record for each victim for theevidence supplied. You may not have all existingantemortem dental records for the victim from outsidesources. This may lead to discrepancies in thean temor tem record and pos tmor tem recordcomparison. The quality, quantity, and variety ofdental record documentation of this antemortemevidence present the major obstacles in this section.Clearly, all antemortem evidence must be compiled toa single antemortem dental record form as shown infigure 10-16, to provide a composite antemortempicture. The latter (computer/description codescolumn) may be easily compared to the postmortemfindings recorded on a postmortem dental record ofsimilar format. Comparing dental records sent directlyfrom dental offices with a postmortem record is a nearimpossible task. At least two members of theantemortem dental record staff should review eachcomposite antemortem dental record as a qualitycontrol mechanism. Figure 10-17 shows a dental staffreviewing antemortem dental records. The completedantemortem composite form should also be qualitychecked against antemortem dental radiographs.

COMPUTER SUPPORT

In this day of data management and wordprocessing, computers can now play a major role inforensic dental ID. The software we use is called theComputer Assisted Postmortem Identification(CAPMI) referenced in figure 10-18.

The basic principle is one in which antemortemand postmortem databases are built using theinformation charted on the antemortem andpostmortem forms. These two databases are runagainst each other and the possibilities of matches areranked to produce a most likely identities list. This listis then used by the forensic team to assist in the final IDprocess. The list does not make an ID, but merelyminimizes the number of records that must be

compared manually by the team. The advantage isthat, instead of having to look at every record to make acomparison, the dental officer or dentist who isreviewing the record is initially guided to the mostlikely match. This is tremendously efficient and offersa significant savings in time. CAPMI may be installedeither on a portable or desktop computer. Yourcommand can obtain copies of CAPMI software andinstructions free of charge by writing to the followingaddress:

The DirectorArmed Forces Institute of PathologyAttn: AFIP-AMS14th & Alaska Ave, NWWashington, DC 30306-6000

ANTEMORTEM/POSTMORTEMRECORDS COMPARISON

The last section in the dental forensic ID processcompares the antemortem and postmortem records.Here the results of all previous work are seen. Armedwith the antemortem record and radiographs,postmortem record and radiographs, CAPMI printout(if used), and a summary sheet, the forensic team startsthe process of comparing records and films. The sizeof the section is dependent on the number of fatalities,since there is a requirement to place all postmortemdental records face-up on tables in numerical order fora comparison with the antemortem composite dentalrecords, as shown in figure 10-19.

After all postmortem dental records have beenplaced as described, the staff can systematicallycompare- the antemortem dental composite recordsas they are received with the postmortem dentalrecords placed on the table. This is done by handcarrying the composite antemortem record andwalk ing a longs ide the t ab les v i ewing thepostmortem dental records looking for a significantpoint of comparison, such as a crown on tooth #30.Once significant points of comparison are notedbetween the antemortem and postmortem dentalrecord forms, the radiographs of the respectiverecords can be reviewed and a possible matchestablished. Figure 10-20 shows dental teammembers reviewing radiographs.

If it is possible to determine the gender of thedisaster victims, it is possible to reduce the manualcomparison task by placing the postmortem records in

10-18

Figure 10-16.—Completed antemortem dental record form.

10-19

Figure 10-17.—Reviewing antemortem dental records.

numerical order on table by gender. Postmortem time. Figure 10-21 shows an example of a completed

records of children may also be individually managed. dental ID summary sheet.

To provide quality control, provide the team leaderof the forensic dentistry section the antemortem andpostmortem dental records of potential positive IDestablished by the staff. The leader must reconstructthe positive dental ID. A dental identification formthat summarizes the ID data can be completed at this

This form is a tool in the decision-making anddocumentation process. It is used to provide rapidanswers to questions when the team leader of theforensic dentistry section meets with the IdentificationCenter chief at which time evidence regarding eachcase is presented. Only after all sections have

10-20

Figure 10-18.—Computer Assisted Postmortem Identification (CAPMI).

presented their evidence and all inconsistencies havebeen explained or addressed should the IdentificationCenter chief sign the case out as a positive ID. Afterthe case has been signed out as a positive ID, theantemortem and postmortem dental records andassociated evidence should be combined with thesummary sheet into a single completed file. Theantemortem composite dental record should be placedin the completed file only if the full dentition waspresent with the remains or if all dental/oral fragmentshave been recovered. If this is not the case and anadditional oral fragment is recovered, thepostmortemfragment may go unidentified since the necessaryantemortem dental record was placed in the completedfile. This mistake is made in almost every disaster.Please avoid it! In the consolidation process, theantemortem and postmortem dental radiographs thatprovided the conclusive evidence of the positive dental

identification should be photographed. Thesephotographs or slides are indispensable for recordkeeping purposes and provide a superior method ofdisplaying the evidence in court.

EQUIPMENT, SUPPLIES, ANDFACILITIES

The fol lowing equipment, supplies, andfacilities as listed in Tables 10-1, 10-2, and 10-3 arerecommended for use in forensic dental operations.The items mentioned below are only a recommendedlist. Most of the equipment and supplies can bemaintained in a medium-size tackle box and canvasbags for immediate availability and easy transport tothe ID site. Your command should plan to add orsubtract items or change quantities according to yourlocal requirements.

10-21

Figure 10-19.—Postmortem dental records.

Figure 10-20.—Reviewing radiographs.

10-22

Figure 10-21.—Dental identification summary sheet.

10-23

Table 10-1.—Equipment for up to 50 casualties

DESCRIPTION QUANTITY

50 KVP Endo X-ray unit, portable, self-contained

Portable lead screens

X-ray badges

X-ray film processor, with daylight loader

Fiberoptic light

Surgical saw (autopsy)

Headlamps

X-ray view boxes

Slide duplicator

Extension cords, 50 ft

CAPMI software and computer

35mm camera

Camera with self-developing film

Security badges

File cabinets, 4 drawer

Tables or gurney carts

1

4

9

1

1

1

2

3

1

3

1

1

1

15

1

As needed

Table 10-2.—Forensic Dentistry Kit (Supplies)


35mm film, 36 exposure

Paper pads

Identification forms:Postmortem, Antemortem, and Summary reports

Tags with string or wire

Manila envelopes for case records

Masking tape

Stapler with staples

Large felt tip markers

Felt tip pens (black ink)

Plastic denture bags

Pencils

Clip boards

Paper cups

10 rolls

1 0

100 each

125

100

2 rolls

2

1 2

1 2

1 box LG

1 box SM

2 boxes

1 0

1 box

10-24

Table 10-2.—Forensic Dentistry Kit (Supplies)—Continued


Work gloves, leather

Scrub suits

Surgical gowns, disposable

Surgical gloves, sizes 7 1/2 & 8

Surgical mask

D e n t a l X - r a y f i l m , d o u b l e e x p o s u r e

Chemicals for film processing

Self-developing film

Magnifying glass

L o o p s

Sodium hypochlorite

Safety glasses

Flashlights

Handsaw

Straight and curved retractors

Scaple handles

S c a p l e # 1 0 , # 1 5 , # 2 0

Large scissors, surgical

Small scissors, surgical

Large hemostats

Mouth props, large and small

Tongue blades

Cotton applicators

Mouth mirrors

Explorers

Periodontal scalers

Cutting pliers

Straight pliers

Straight chisel

M a l l e t

Millimeter rule

Spatula, #7 wax

Disclosing solution

Hydrogen peroxide solution

4 pairs

20 pairs

3 0

3 boxes each

1 box

10 boxes

as needed

5 rolls

1

2

1 gallon

5

6

1

1 set

4

1 box each

2

2

4

1 each

1 box

1 box

1 2

1 2

3

1

1

1

1

3

1

2 bottles

1/2 gallon

10-25

Table 10-2.—Forensic Dentistry Kit (Supplies)—Continued


4 x 4 sponges 10 boxes

Toothbrushes 20

Computer terminal paper 1 box

Ribbon for terminal printer 1

Occlusal X-ray film 1 box

Soap, antibacterial 6 bottles

Towels 10

Scrub brushes

Rubber aprons

5

10

Trash can liners 1 box

Table 10-3.—Office Facilities

Office facilities:

Room for antemortem records

Room for postmortem records

Postmortem exam area

Access to:

Copy machine/computer

Watts/DSN telephone lines

Refrigeration

10-26

APPENDIX I

REFERENCES USED TO DEVELOPTHIS TRAMAN

Dental Assistant Journeyman, Volume I, Dental Administration, Management, andSupply, CDC 4Y051A, Extension Course Institute, Air Education and TrainingCommand, Air University, Maxwell Air Force Base, Montgomery, AL.

Dental Assistant Journeyman, Volume 2, Dental Equipment and Instruments, CDC4Y051A, Extension Course Institute, Air Education and Training Command,Air University, Maxwell Air Force Base, Montgomery, AL.

Dental Assistant Journeyman, Volume 3, Basic and Dental Sciences, CDC 4Y051A,Extension Course Institute, Air Education and Training Command, AirUniversity, Maxwell Air Force Base, Montgomery, AL.

Dental Assistant Journeyman, Volume 4, Applied Dental Sciences, CDC 4Y051A,Extension Course Institute, Air Education and Training Command, AirUniversity, Maxwell Air Force Base, Montgomery, AL.

Dental Assistant Journeyman, Volume 5, Radiology and Dental Health, CDC98150, Extension Course Institute, Air Education and Training Command, AirUniversity, Maxwell Air Force Base, Montgomery, AL.

Dental Assistant Journeyman, Volume 6, Infection Control and EmergencyProcedures, CDC 98150, Extension Course Institute, Air Education andTraining Command, Air University, Maxwell Air Force Base, Montgomery,AL.

Dental Assistant Journeyman, Volume 7A, Clinical Procedures, CDC 98150-07A,Extension Course Institute, Air Education and Training Command, AirUniversity, Maxwell Air Force Base, Montgomery, AL.

Dental Assistant Journeyman, Volume 7B, Clinical Procedures, CDC 4Y051,Extension Course Institute, Air Education and Training Command, AirUniversity, Maxwell Air Force Base, Montgomery, AL.

Dental Assistant Journeyman, Volume 7C, Clinical Procedures, CDC 4Y051B,Extension Course Institute, Air Education and Training Command, AirUniversity, Maxwell Air Force Base, Montgomery, AL.

Dental Infection Control Program, BUMEDINST 6600.10A, Department of theNavy, Bureau of Medicine and Surgery, Washington, DC, 1996.

Dental Records Treatment Manual, MED-631, Department of the Navy, Bureau ofMedicine and Surgery, Washington, DC, 1997.

Forensic Dentistry Manual, 32nd Annual Course, Armed Forces Institute ofPathology, Washington, DC, 1996.

Instructor's Manual for Basic Life Support, American Heart Association, NationalCenter, Dallas, TX, 1994.

Manual of the Medical Department, US. Navy, NAVMED P-117, Change 112,Department of the Navy, Bureau of Medicine and Surgery, Washington, DC,1996.

AI-1

NAVMED 6600/3, Dental Health Questionnaire, BUMEDINST 6600.12,Department of the Navy, Bureau of Medicine and Surgery, Washington, DC,1993.

Resuscitation Training, BUMEDINST 1500.15A, Department of the Navy, Bureauof Medicine and Surgery, Washington, DC, 1996.

Trial Implementation of Dental Examination and Associated Forms, BUMEDNotice 6600, Department of the Navy, Bureau of Medicine and Surgery,Washington, DC, 1997.

AI-2

INDEX

A

Accession examination, 2-4Acrylic repairs, 8-25

denture base repairs, 8-25denture tooth repairs, 8-27

Additional dental treatment forms, 2-25Consultation Sheet, SF513, 2-25

Air polishing unit, 3-7Alveolar Osteitis, 5-5Alveoloplasty, 5-4Amalgam restorations, 4-2Anatomical landmarks, 1-38Anesthetic, local, 4-19Antemortem dental examination, 10-18

computer support, 10-18Aspirating syringe, 4-7Aspirating syringe needle, 4-7Assembling matrices, 4-13Assisting in dental surgery, 5-20

circulating assistant, 5-20scrub assistant, 5-20

Automatic film processors, 1-27with daylight loaders, 1-27without daylight loaders, 1-27

B

Basic dental procedures, 4-19Basic life support, 9-3

CPR course certifications, 9-3oxygen, use of, 9-4resuscitating devices, 9-3

Biopsy, 5-4Bisecting-angle technique, 1-14, 1-23

guidelines, 1-21

C

Calculus removal, 3-12cement and insulating base instruments,4-6

Cast fabricating, 8-17impression, 8-17materials and mixing, 8-17preparing to pour impressions, 8-17

Cast trimining, 8-19preliminary steps, 8-19trimming, 8-19

Cement and insulating base instruments, 4-6Charting, general, 2-6Charting markings, 2-6, 2-9

abbreviations/acronyms, 2-6general, 2-6

Circulating assistant, 5-20Composite resin instruments, 4-5Comprehensive examination, Type 1, 2-3Computer Assisted Postmortem

Identification (CAPMI), 10-18Consulatation Sheet, SF513, 2-25Current status form, 2-19Custom impression trays, 8-20

fabricating a tray with spacers, 8-22spacers, 8-20trays without spacers, 8-21

Cutting instruments used in dental surgery, 5-9

D

Darkroom procedures, 1-29Dental classifications, 2-4

class 1, 2-6class 2, 2-6class 3, 2-6class 4, 2-6

Dental examinations, 2-1examination duties, 2-21patient preparation, 2-1pre-examination duties, 2-1

Dental floss, use of, 3-17Dental Exam Form (EZ603), 2-21

completing the back, 2-22Dental Exam Form (EZ603A), 2-22Dental identification, 10-5

classification, 10-10principles, 10-7problems, 10-7radiographic comparision, 10-8why dental identification works, 10-5

Dental radiology, 1-1Dental X-ray machines, 1-3

control panel, 1-4cylinder, 1-3machine operation, 1-5operational check, 1-4securing the machine, 1-5tubehead, 1-3user maintenance, 1-6Cavity preparation, 4-23

INDEX-1

Dentifrice, 3-18Designations, charting, and abbreviations, 2-6DTR infection control, 8-35

E

Electrosurgery apparatus, 6-9Elevators, surgical, 5-10Emergencies, DTR, 9-1

emergency response team, 9-2preventing, 9-1vital signs, 9-1

Emergencies, other, 9-4anaphylatic shock, 9-6angina pectoris, 9-4asthma attack, 9-7hyperventilation, 9-7hypoglycemia, 9-6seizures, 9-7shock, 9-4syncope, 9-5

Endodontic procedures, 7-3apicoectomy and periapical curettage, 7-4bleaching, 7-4incision and drainage, 7-4pulp capping, 7-3pulpotomy and pulpectomy, 7-3retrograde filling, 7-4root amputations, 7-4root canal therapy, 7-4

Endodontics, 7-1accessories, 7-6anesthesia, 7-11apicoectoiny, 7-4, 7-14appointments, 7-5bleaching, 7-4canal cleansing and shaping, 7-13causes, 7-1diagnosis, 7-1function, 7-1incision and drainage, 7-4instruments, 7-6irrigation, 7-12isolation, 7-11materials, 7-5medications, 7-13periapical curettage, 7-4pulp capping, 7-3pulp removal, 7-12pulpotomy and pulpectomy, 7-3retrograde filling, 7-4root amputations, 7-4root canal filling, 7-14root canal therapy, 7-4

Endodontic therapy, 7-11anesthesia, 7-11apicoectoiny, 7-14canal cleansing and shaping, 7-13isolation, 7-11irrigation, 7-12medications, 7-13opening the pulp and canals, 7-12removing the pulp, 7-12root canal filling, 7-14

Equipment preparation, 2-2dental chair, 2-2

Examination and informed consent,surgery, 5-1

Examination duties, 2-2Examination types, 2-3

antemortem, dental, 10-18antemortem/postmortem, records

comparison, 10-18comprehensive examination, Type 1, 2-3oral examination, Type 2, 2-3other examination, Type 3, 2-3postmortem examination, 10-15screening evaluation, Type 4, 2-4

Exostosis, 5-4Explorer, 3-10Exposure factors, film alignment, variations, 1-14

F

Faulty radiographs, 1-34Film positioning devices, 1-26Film processing, 1-29

automatic processing, 1-29darkroom procedures, 1-29faulty radiographs, 1-34film viewers, 1-36mounting radiographs, 1-36safety precautions, 1-29

Finger rest, 3-10Fixed prosthetics, 8-1

artificial crowns, 8-2inlay, 8-1insertion, 8-32interim fixed partial denture, 8-4onlays, 8-1partial denture, 8-2procedures, 8-29resin-bonded fixed partial denture, 8-4splints, 8-4

Foreign body removals, 5-5Four-handed dentistry, 4-15

zones and positions, 4-15Forceps, tooth extraction, 5-13

INDEX-2

Forensic dentistry, 10-1equipment, supplies, facilities, 10-21estate, 10-1identification, other methods, 10-2insurance, 10-1intelligence, 10-2legal, 10-1manpower, 10-1psychological, 10-1

Forensic examination, 2-8charting and markings, 2-9

Forensic form, 2-8hard and soft tissue remarks section, 2-18

Forms, EZ603A, 2-21Frenectomy, 5-4Fundamentals of dental radiology, 1-1

H

Hand-cutting instruments, 4-1Home care, 3-16

I

Incision and drainage, 5-5Identification of operative instruments. See operative

instruments.Implants, 5-5Indications and contraindications, surgery, 5-1Infection control, 1-26

automatic film loader with daylight loader, 1-27automatic film loader without daylight loader, 1-27barrier control, 8-35darkroom, 1-26disposable plastic film packets, 1-27DTR infection control, 8-35film positioning devices, 1-26handwashing, 1-26intraoral film packets, 1-27panoramic unit bite blocks, 1-26X-ray chair, 1-28X-ray tubehead and controls, 1-28

informed consent, 5-1Instrument exchange, 4-16Instrument grasp, 3-10Instrumentation, scaling, 3-12Instrument preparation, 2-2Instrument sharpening, 6-14

periodontal chisel, 6-14periodontal curette, 6-13periodontal knife, 6-13scalers, 6-14sharpening devices, 6-12

Interproximal (bitewing) examination, 1-22mounting, 1-37parallel placement techique, 1-23

Intraoral film, 1-27, 1-6disposal plastic film packages, 1-27precious metals recovery program, 1-7storage, 1-6

Intraoral radiographs, 1-6Impressions preliminary, 8-15

impression procedures, 8-15materials required, 8-15

Irrigation and aspiration, 4-20

M

Mass casualty operations management, 10-10dental radiology, 10-12dental registrar, 10-11dental team leader, 10-11oral surgery, 10-11

Mandibular occlusal examination, 1-25Maxillary occlusal examination, 1-25Matrix retainers, 4-12

assembling, 4-13Medical emergency guidelines, 9-3Medical examination (SF88), report of,

2-23Medication, administration, 9-8

adverse react ion, 9-8treatment, 9-8

Miscellaneous instruments, material and equipment,4-7

surgical forceps, 5-8surgical instruments, 5-5

Modified pen grasp, 3-10Mounting radiographs, 1-36

anatomical landmarks, 1-38full mouth, 1-38interproximal, 1-37procedures, 1-39

Mouthguards, 8-22fabricating mouthguards, 8-23

Mouth mirror, 3-9

O

Occasions for dental examination, 2-4accession, 2-4overseas screening, 2-4periodic examination, 2-4physicals, 2-4separation, retirement, and special programs,

2-4

INDEX-3

Occlusal examination, 1-24Operative dentistry, 4-1

areas of, 4-1four-handed dentistry, 4-15operative procedures, 4-21supply procedures, 4-27

Operative instruments, 4-1amalgam restoration instruments, 4-2composite resin instruments, 4-5oral examination, Type 2, 2-23

Operative procedures, 4-21Oral hygiene instructions, 3-15

aids, 3-19Oral prophylaxis, 3-1

patient and operator positioning, 3-2procedures, 3-11system approach to systematic scaling, 3-11

Oral surgery assistance, 5-1assisting in dental surgery, 5-20post-operative procedures, 5-25surgical instruments, 5-5surgical procedures, 5-24

Oral surgery function, 5-1examination and informed consent, 5-1indications and contraindications, 5-1

Oral surgery procedures, 5-3tooth extractions, types, 5-3

Osteotomy, 5-4Other examination, Type 3, 2-3Overseas screening, 2-4

P

Pain and anxiety control, surgery, 5-3Palm grasp, 3-10Panoramic radiographs, 1-40

labeling, cassette, 1-42operating machine, 1-42operational check, machine, 1-40preparing the film, 1-42requirements for a good result, 1-42user maintenance, 1-42

Paralleling placement technique, 1-23Paralleling technique, 1-8Passing and receiving instruments, 4-16Patient and operator positioning, 3-2Patient dismissal, examination, 2-27

Patient preparation, X-ray, 1-7Pen grasp, 3-10Pericoronitis, 5-5

Periapical examination, 1-8bisecting-angle technique, 1-21full mouth, 1-10

Periapical examination—Continuedguidelines for taking, paralleling technique,

1-10infect ion control, 1-26interproximal (bitewing) examination,

1-22Periapical mounting, 1-38Periodic examination, 2-4Periodontal equipment, 3-4

air polishing unit, 3-7sonic scaler, 3-9ultrasonic scaler, 3-4

Periodontal instruments, 6-5furcation probes, 6-5periodontal probes, 6-5scaling and root planing, 6-5

Periodontal procedures (routine), 6-9gingival curettage, 6-10occlusal equilibration, 6-9periodontal scaling, root planning, and root

desensitization, 6-10Periodontal procedures (surgery), soft and hard

tissues, 6-10bicuspidization, 6-12gingivevtomy, 6-10gingivoplasty, 6-10metallic implants, 6-12osseous surgery, 6-11periodontal flaps, 6-10periodontal soft tissue grafts, 6-10root amputation, hemisection,surgical dressings, 6-12

Periodontal scaling, 3-11calculus removal, 3-12

Periodontal scaling, instruments, 3-9, 6-5root planing instruments, 6-5

Periodontal surgery instruments, 6-8electrosurgery apparatus, 6-9occlusal equilibration, 6-9periodontal chisels, hoes and files, 6-9periodontal curettes and sickles, 6-8periodontal knives, 6-8periosteal elevators, 6-8routine periodontal procedures, 6-9

Periodontics, 6-1charting, 6-2contraindications, 6-1examination, 6-2function, 6-1indications, 6-1treatment plan, 6-5

Periodontic assistance, 6-1Physicals, 2-4

INDEX-4

Pin amalgam set, 4-15Pits and tissures sealants, 3-19Polishing teeth, 3-13Precious metals recovery program, 1-7Pre-examination duties, 2-1

patient preparation, 2-1instrument/equipment preparation, 2-2

Presurgical procedures, 5-21patient scrubbing procedures, 5-21preparing the surgical room, 5-21receiving the patient, 5-21surgical team, scrubbing, gloving, and draping,

5-21Preventive dentistry, 3-1

instrument grasp, 3-10oral hygiene instruct ions, 3-15oral prophylaxis, 3-1periodontal scaling instruments, 3-4, 3-9sealants, 3-19technician, 3-1types, uses, and maintenance of periodontal

equipment, 3-4Preparation for oral prophylaxis, 3-1

contraindications to, 3-2Prosthetics appliances, maintenance of,

3-19Prosthetics laboratory, 8-33

case request, 8-34cases while in the laboratory, 8-34impressions, 8-34infection control, 8-35stone or plaster cast, 8-34

Prosthodontic assistance, 8-1chairside, 8-27DD Form 2322, 8-29DTR infection control, 8-35

Prosthodontic equipment, 8-9alcohol torch, 8-10articulator, 8-10bench lathe, 8-10bunsen burner, 8-11cast trimmer, 8-11face bow, 8-12impression trays, 8-12mixing bowl, 8-13pneumatic curing unit, 8-13vacuum adapter, 8-13vibrator, 8-14

Prosthodontic instruments, 8-14crown remover, 8-14knives, 8-14roach carver, 8-14spatulas, 8-15

Prosthodontic materials, 8-6acrylic resins, 8-8dental alloys, 8-6dental waxes, 8-8gypsum products, 8-7impression materials, 8-6other prosthodontic materials, 8-9

Post-operative procedures, 5-25common postsurgical complications, 5-27control of bleeding, 5-25postsurgical instructions, 5-25

Pulpectomy and root canal treatment, 7-5suture removal, 5-27

appointments, 7-5endodontic materials, 7-5instruments and accessories, 7-6

R

Radiation safety, 1-2assistant protection, 1-2patient protection, 1-2X-ray film log, 1-2

Radiology, postmortem, 10-12Recording dental treatment, 2-7

current status form, 2-19dental exam form, 2-21forensic examination, 2-8instructions for completing the EZ603-A, 2-22

Removable prosthetic prostheses, 8-4complete dentures, 8-5

Report of Medical Examination, (SF88), 2-23Reserve Dental Assessment and Certification,

NAVMED 6600/12, 2-27overdentures, 8-6removable partial dentures, 8-5

Rubber dam instruments, 4-7application, 4-10

S

Scaling instruments, 3-12, 6-5Screening evaluation, Type 4, 2-4Screening examination, 3-4Scrub assistant, 5-20Sealants, 3-19Separation, retirement, and special programs, 2-4Sensitivity, 3-18Sequestrectomy, 5-5Sonic scaler, 3-9Standard abbreviations and acronyms, 2-6Supply procedures, 4-27Surgical air drill, 5-18Surgical instruments, 5-5

INDEX-5

Surgical procedures, 5-24

instrument setup and materials,5-25

rules of aseptic technique, 5-24

U

T

Terminology and classification of cavities,

4-21

Toothbrushes, electric, 3-16

Toothbrushing, effective, 3-16

evaluation, 3-18Tooth surfaces, 2-6

Tramautic wound repair, 5-5

Ultrasonic scaler, 3-4maintenance, 3-7

V

Vacuum-formed templates, fabricating, 8-22, 8-23

X

X-ray chair, 1-28X-ray film log, 1-2X-ray, patient preparation, 1-7X-ray tubehead and controls, 1-28

Z

Zones and positions, 4-15

INDEX-6

A S S I G N M E N T 2

Textbook Assignment: "Dental Examinations," chapter 2, pages 2-1 through 2-27.

2-1. Which of the following procedures is one of thebasic professional services provided on an annualbasis to Sailors by the Navy dental team?

2-7. What is the primary purpose for conducting annualdental examinations?

2-2

1. Dental examination2. Medical screening3. Prosthetic treatment4. Orthodontic treatment

When seating the patient for a dental exam, whereshould you position the dental light to avoid shiningthe light in the patient's eyes?

1. To qualify personnel for special pay2. To qualify personnel for special duty3. To qualify personnel for special programs4. To access the readiness status of active duty

personnel

2-8. What form should you use to document the findingsof a dental examination for overseas screening?

2-3.

1. Above the patient's mouth2. Beneath the patient's chin3. Above the patient's forehead4. Beneath the patient's chest

Which of the following dental instruments and/ormaterials should be included in a basic dentalexamination instrument setup?

2-9.

1. NAVMED 1050/32. NAVMED 1300/13. NAVMED 6000/24. NAVMED 6600/12

A member's commanding officer can approve amember for overseas assignment even when thedental officer recommends disapproval.

2-4.

1. A mouth mirror and explorer2. A periodental probe and cotton forceps3. A tongue depressor, cotton rolls, and gauze4. All of the above

Dental examinations are classified by what totalnumber of examination types?

2-10.

1. True2. False

All active duty members and reservists should havemedical examinations at which of the followingevents or intervals?

2-5.

1. One2. Two3. Three4. Four

What type of examination is a comprehensive hardand soft tissue examination routinely done withstudy models?

1. Annually after age 602. Every 5 years through age 503. Upon entry to enlisted or commissioned active

duty

2-11.

4. All of the above

What dental classification indicates that the patient'sdental condition, if not treated or followed up, couldhave the potential, but is not expected to, result indental emergencies within the next 12 months?

1. Type 1 1. Class 12. Type 2 2. Class 23. Type 3 3. Class 34. Type 4 4. Class 4

2-6. Which of the following personnel may perform atype 4 dental screening evaluation?

1. A dental officer2. A dental hygienist3. A qualified dental assistant4. All of the above

8

2-12. When identifying and locating caries or existingrestorations, how should you refer to an 8-MIDdesignation?

1. Distal, incisal, mesial aspects of a leftmaxillary central incisor

2. Distal, incisal, mesial aspects of a leftmandibular incisor

3. Mesial, incisal, distal aspects of a rightmaxillary central incisor

4. Mesial, incisal, distal aspects of a rightmandibular incisor

2-13. When recording the use of copal varnish in thedental treatment record, which of the followingabbreviations should you use?

1 .

2.

3 .

4.

1. CV2. Cop3. Copal4. Cop Var

2-14. What abbreviation should you use when recordingthat the patient was informed of examinationfindings and treatment plan?

1. PTINF2. PTINFTX3. PTINFTXPL4. Pt info tx plan

2-15. When charting the top section of the ForensicExamination form, what symbol should you use toindicate missing teeth or teeth not visible in thepatient's mouth?

1. O2. / /3. X4. =

2-16. Which of the following terms is often used whenreferring to a double occlusal restoration?

2-17.

1. Ace2. Duce3. Snake eyes4. Double ace

Nonmetallic restorations are made of which of thefollowing types of materials?

1. Acrylic resin2. Glass Ionomer3. Fissure sealant4. All of the above

2-18. A nonmetallic permanent restoration is annotated bydrawing an outline of the restoration showing size,location, shape, and inscribing vertical lines withinthe outline.

1. True2. False

2-19. When charting a Forensic Examination form, whatmethod, if any, should you use to describe thedifferences between gold and chrome alloyrestorations?

only

Indicate in the "Remarks" section that therestoration is chrome alloyInscribe horizontal lines in the chrome alloy

Inscribe horizontal lines in the chrome alloyand vertical lines in the gold restorationNone

2-20. When charting, how should you indicate that goldmaterial was used in a fixed partial denture (FPD)?

1. Inscribe vertical lines2. Inscribe horizontal lines3. Inscribe diagonal parallel lines4. Outline each aspect of the FPD only

2-21. What procedure should you use to chart the presenceof supernumerary teeth?

1. Insert a "D" in the location on the toothnumber line

2. Insert a "S" in the location on the toothnumber line

3. Draw an outline of the tooth in its approximatelocation

4. Both 2 and 3 above

2-22. The Forensic Dental Examination form is completedusing black ink.

1. True2. False

2-23. The Remarks section of the Forensic DentalExamination form is used to differentiate betweenwhich of the following types of dental materials?

1 . Sealants2. Temporaries3. Composites4. All of the above

9

2-24. What number of Angle classifications could beused on the Forensic Examination form?

1 . One2. Two3. Three4. Four

2-25. On the Forensic Examination form, what methodshould you use to indicate that a patient does NOThave a soft tissue condition?

1. Write "none" in the Soft Tissue Remarkssection

2. Write "none" in the Hard Tissue Remarkssection

3. Write "no existing conditions" in the SoftTissue Remarks section

4. Leave blank if a condition does not exist

2-26. Where in the occlusion section of the ForensicExamination Form should you document andrecord any other occlusal condition not listed?

1. Section A2. Section B3.4.

RemarksHard Tissue Remarks

2-27. Which of the following non-pathologic findingsshould you annotate in the Hard Tissue Remarkssection on the Forensic Examination form?

1. Tori2. Rotated teeth3. Intrinsic staining4. All of the above

2-28.

2-29.

2-30.

2-31.

2-32.

What procedure should you use when a patientrequires the completion of a new Current Statusform?

1. Complete box 1 of the Current Status formonly

2. Complete boxes 1 and 2 of the Current Statusform

3. Transfer the information from the previousforms to the new Current Status form

4. None, a patient's Current Status form shouldnever need to be replaced

Which of the following conditions should beannotated in pencil in box 1 of the Current Statusform?

1. Carious lesions2. Periradicular lesions3. Indications for root canal treatment4. All of the above

The same charting symbols are used in boxes 1 and2 on the Current Status form.

1. True2. False

What does an even line drawn on the root of thetooth indicate?

1. Fractured tooth2. Underfilled root canal3. Resorption of the root4. Periapical radiolucency

You should be able to chart the information for theSF-88 by using what box of the Current Statusform?

1 . 12. 23. Both 1 and 2 above4. 4

2-33. Pencil entries are authorized for use in box 2 of theCurrent Status form.

1. True2. False

10

2-34.

2-35.

2-36.

2-37.

2-38.

2-39.

What method, if any, should you use to indicate thematerials used for existing restorations annotated inbox 2 of the Current Status form?

1. Indicate in the "remarks" section the materialsused

2. Indicate in the "remarks" section if thematerial used was an alloy

3. Indicate in the "remarks" section if thematerial used was made out of gold

4. None; there are not any remarks made toindicate materials used

What new dental form provides a record of initialaccession exam and all subsequent periodic, annual,recall, and separation exams?

1. SF 882. SF 6033. EZ 6034. EZ 600

What part of the S.O.A.P includes the reason for thevisit and a statement of the chief complaint?

1. Subjective2. Objective SF 60334:

AssessmentPlan

What part of the S.O.A.P includes the healthquestionnaire review findings?

1. Subjective2. Objective3. Assessment4. Plan

Which part of the S.O.A.P. includes the patient'streatment needs?

1. Subjective2. Objective3. Assessment4. Plan

Which of the following references should you use tocomplete the Dental Examination form?

1. MANMED, Chapter 62. MANMED, Chapter 1634:

BUMEDINST 6100.1NAVMEDCOM 6600.1

2-40.

2-41.

2-42.

2-43.

2-44.

2-45.

The back of the EZ 603 Form may be overprintedwith a command specific format.

1. True2. False

Which of the following forms should you use todocument dental treatment completed from thetreatment plan, dental emergencies, and any othernarrative dental findings?

1. SF 882. SF 5133. EZ 6004. EZ 603A

What color ink should you use for the medical alertentry on the EZ 603A Form?

1. Red2. Blue3. Black4. Green

What form should you use to record the dentalexamination completed in conjunction with amedical physical?

1. SF 882. SF 5133. SF 6004. EZ 600

Which of the following entries should you annotatein the space marked "Remarks and AdditionalDental Defects and Diseases" on the report of theMedical Examination form?

1. Dental classification2. Type of dental exam3. Qualified "YES" or "NO"4. All of the above

What form should you use to refer a patient toanother specialist or to medical for furtherevaluation or treatment?

1. SF 882. SF 5133. SF 5154. EZ 600

11

2-46. Which section on the Consultation Sheet should youleave blank for the person receiving the form todocument his or her findings?

1. Reason for request2. Provisional diagnosis3. Consultation report4. Place of consultation

2-50.2-47. Voluntary Training Unit personnel or Selected

Reserve personnel could require which of thefollowing forms to be completed in conjunction withtheir Type 1 or Type 2 dental exam?

2-49. The dental chair should be placed in which of thefollowing positions to dismiss the patient?

1. SF 5132. SF 6003. NAVMED 6600/124. NAVMED 6150/10

2-48. The Naval Reserve Type 1 or Type 2 dentalexamination should be performed at a minimum ofwhat event or time period?

1. Every year2. Every 5 years3. With any required physical examination4. Both 2 and 3 above

1. Arm raised, lowest, down right position2. Arm raised, lowest, upright position3. Arm lowered, lowest, down right position4. Arm lowered, lowest, upright position

When patients complete their dental examination,you should direct them to make future dentalappointments at which of the followingdepartments?

1. Front desk2. Operative3. Oral Surgery4. Oral Diagnosis

12


Textbook Assignment: "Preventive Dentistry," chapter 3, pages 3-1 through 3-20; and "Operative Dentistry," chapter 4, pages 4-1through 4-27.

3-1. The formulation, supervision, and execution of thePreventive Denistry Program is found in whatSECNAV instruction?

3-2.

1. 6600.12. 6600.23. 6600.34. 6600.5

Which of the following meanings best describes theterm prophylaxis?

3-3.

1. Prevention of disease2. Prevention of calculus3. Prevention of bone loss4. Prevention of stain

Patients with subgingival calculus will have anappointment with which of the following dentalpersonnel?

1. Expanded duty preventive dentistry technician2. Dental hygienist3.4.

DentistBoth 2 and 3 above

3-4. When positioning a patient for an oral prophylaxis,at what degree should the back of the patient’s chairbe angled?

1. 1 52. 2 03. 2 54. 3 5

3-5. What phase, if any, is included in the screeningexamination of a scaling procedure?

1. Periodontal charting2. Examination of patient’s personal tooth brush3. Examination of the teeth and gingival tissues4. None

3-6. Cavitation aids in the mechanical removal of whattwo substances by the vibrating tip?

1. Plaque and carries2. Calculus and carries3. Plaque and calculus4. Calculus and gingivitis

3-7. The water supply pressure of an ultrasonic scalingunit has a maximum range of how many psi?

1. 6 02. 4 03. 2 54. 15

3-8. What ultrasonic tip is most commonly used forsupra and subgingival calculus deposits?

3-9.

1. Beaver-tail2. Chisel3. Universal4. Periodontal probe

The working end of the instrument tip of anultrasonic scaler should be adapted to what degreeangle to the long axis of the tooth?

3-10.

1. 0 to 52. 10 to 153. 15 to 204. 20 to 25

The air polishing unit uses which of the followingmaterials to operate?

1. Air2. Water3. Sodium bicarbonate4. All of the above

3-11. Which of the following areas should be avoidedwhile using the air polishing unit?

3-12.

1. Enamel2. Soft tissue3. Heavy stained teeth4. Middle one-third of the tooth

Which of the following sonic scaler tips isrecommended for patients who experiencesensitivity?

1. Sickle2. Perio3. Beaver4. Universal

13

3-13. Fogging of the mouth mirror can be prevented bywhich, if any, of the following methods?

3-20. Tooth polishing removes what types of materialsfrom the teeth?

1. Using a disinfection solution2. Having the patient breathe through the mouth3.4.

Running the mirror under cold waterNone of the above

3-14. Which of the following is NOT an instrumentgrasp?

1. Pen2. Palm3.4 .

FingerModified pen

3-15. What teeth of the mouth are scaled last using asystematic routine?

1. Maxillary anterior2. Mandibular anterior3.4.

Left maxillary posteriorRight maxillary posterior

3-16. Dental technicians are only allowed to removecalculus in what areas of the mouth?

3-17.

1. Sublingual2. Submandibular3. Subgingival4. Supragingival

Which of the following methods is the easiest wayto detect supragingival calculus?

1. Visually2. Tactile3.4.

Disclosing agentDisinfection agent

3-18. How many basic scaling strokes are there?

1.2.3.4.

OneTwoThreeFour

3-19. Which scaling stroke is made at a 45° angle to thelong axis of the tooth?

1. Oblique2. Vertical3. Horizontal4. Exploratory

3-21.

3-22.

3-23.

3-24.

3-25.

3-26.

1. Overhangs2. Plaque and stains3. Plaque and calculus4. All of the above

At what speed should a handpiece with aprophylaxis attachment run?

1. Slow2. Medium3. Fast4. Both 2 and 3 above

When polishing teeth, what type of motion should arubber cup be in to keep contact with the tooth?

1. Bouncing2. Constant3. Vertical4. Horizontal

After a fluoride treatment, patients should not rinse,drink, eat, or smoke for at least how many minutes?

1. 1 02. 2 03. 3 04. 4 0

To prevent dental disease, at least how often duringa 24-hour period should bacterial plaque beremoved?

1. Once2. Twice3. Three times4. Four times

Which of the following toothbrushing techniques iseffective for a patient to perform?

1. Electric2. Overhand3.4.

Modified BassModified Tooth

To properly floss, about how many inches of flossshould you cut off?

1. 1 22. 1 83. 2 44. 3 6

14

3-27.

3-28.

3-29.

3-30.

3-31.

3-32.

3-33.

What device is used to direct floss in betweenabutments and beneath pontics?

1. Toothpick2. Oral irrigator3. Floss threader4. Interdental proximal brush

To what surfaces on a tooth will pit and fissuresealants bond?

1. Facial and lingual2. Mesial and distal3.4.

Cusp and mamelonsDepressions and grooves

Sealants are highly effective in preventing pit andfissure caries in which of the following teeth?

1. Premolars and molars2. Premolars and incisors3. Incisors and molars4. All of the above

A rubber dam is the only method of isolation to beused for the application of pit and fissure sealants.

1. True2. False

What percent of phosphoric acid solution is used toetch teeth for pit and fissure sealants?

1. 10 to 202. 20 to 303. 30 to 504. 90 to 100

What type of appearance will the area of a toothhave that has been etched, washed, and dried?

1. Smooth2. Frosted3. Pitted4. Dark

Which of the following is the most common reasonfor sealant failure?

1. Expired material2. Insufficient curing time3. Contamination of the material4. Contamination of the etched surface

3-34.

3-35.

3-36.

3-37.

3-38.

3-39.

Operative dentistry is concerned with the preventionand treatment of defects of what tooth surfaces?

1. Enamel and cementum2. Enamel and dentin3. Dentin and cementum4. Cementum only

Which of the following instruments is usedprimarily to remove debris from tooth cavities?

1. Hoes2. Chisels3. Hatchets4. Spoon excavators

An even-numbered gingival margin trimmer isdesigned for use on which of the following toothsurfaces?

1. Mesial2. Distal3. Facial4. Lingual

An odd-numbered gingival margin trimmer isdesignated for use on which of the following toothsurfaces?

1. Mesial2. Distal3. Facial4. Lingual

What type of working end does an amalgam carrierhave for transportation?

1. Solid2. Layered3. Pointed4. Hollow

An amalgam condenser is often referred to as whichof the following instruments?

1. Carvers2. Burnishers3. Pluggers4. Carriers

15

3-40.

3-41.

3-42.

3-43.

3-44.

3-45.

3-46

Which of the following instruments is designed forcarving proximal tooth surfaces?

1. Tanner #52 .3.

#1/2 HollenbackFrahm 2/3

4 . Cleoid-discoid

Which of the following advantages will occur tocomposite restorations when using a plasticinstrument?

1 . Will not discolor2. Will not bend3.4.

Will not meltWill not break

What number spatula is used to mix small quantitiesof cement?

1. 3132. 3223.4.

324324A

What length needle measured in inches is normallyused for mandibular injections?

1. 1 1/42. 1 3/43.4.

1 7/81 13/16

The working end of a rubber dam punch is designedwith which of the following mechanisms?

1. Plunger and spindle2. Plunger and wheel3.4.

Wheel and spindleSpindle and clamp

A "W" prefix on a rubber dam clamp indicateswhich of the following designs?

1. Without clamp2. Without wrapper3. Without slipping4. Without wings

Which of the following rubber dam frames is themost popular?

1. "A" frame2. Young3. Wizard4. Woodbury

3-47.

3-48.

3-49.

3-50.

3-51.

3-52.

3-53.

What type of material is always tied around a rubberdam clamp before placement in the mouth?

1. Floss2.3.

Dental chainRubber latex

4. Clamp retriever

Which of the following types of matrix bands ismost commonly used in restorative dentistry?

1. Wide #22. Junior #133.4.

PrecontouredStraight #1

Extensions on the Wide #2 matrix bands are knownby which of the following terms?

1. Bumps2. Aprons3. Wings4. Circles

Which of the following is the most commonly usedmatrix retainer?

1. Universal #12. Universal adult3. Universal straight4. Universal contra-angled

Wood or clear plastic wedges measure about howlong in length?

1. 1 inch2. 1/2 inch3. 3/4 inch4. 1/4 inch

The operator’s zone for a right handed dentist islocated between which of the following positions?

1. 1 and 3 o’clock2. 2 and 4 o’clock3.4.

5 and 8 o’clock8 and 11 o’clock

The assistant's zone for a right handed dentist islocated between which of the following positions?

1. 1 and 3 o’clock2. 2 and 4 o’clock3. 5 and 8 o’clock4. 8 and 11 o’clock

16

3-54.

3-55.

3-56.

3-57.

3-58.

3-59.

3-60.

The transfer zone is located between which of thefollowing positions?

1. 8 to 11 o'clock2. 2 to 4 o'clock3. 3 to 6 o'clock4. 4 to 8 o'clock

The static zone is located between which of thefollowing positions?

1. 8 to 11 o'clock2. 11 to 1 o'clock3.4.

11 to 2 o'clock4 to 8 o'clock

How many inches should the dentist’s eyes be fromthe treatment site if the patient is properlypositioned?

1. 5 to 122. 14 to 163. 18 to 364. None of the above

In what zone will the instrument exchange betweenthe dentist and the assistant take place?

1. Operator's2. Assistant's3. Transfer4. Static

Dental materials are exchanged between the dentistand the assistant in what zone?

1. Operator's2. Assistant's3. Transfer4. Static

The needle end of a carpule is sealed with a rubbermembrane held in place by what type of material?

1. Metal band2. Rubber band3. Copper band4. Plastic band

If you must recap a needle, what technique, if any,should be used?

1. One-handed scoop2. Two-handed scoop3. Twist and turn scoop4. None

3-61.

3-62.

3-63.

3-64.

3-65.

3-66.

3-67.

What device is used to remove blood, pus, saliva,and debris from the oral cavity?1. Low-volume ejector2. High-volume ejector3.4.

High-volume evacuatorHigh-volume aspirator

What type of cavity is present when three or moresurfaces are involved?

1. Large2. Small3.4.

MediumComplex

When the dentist has finished removing the toothstructure in a cavity preparation, what type offeeling will the dentin have when felt by anexplorer?

1. Firm2. Loose3. Brittle4. Semi-hard

What is the last cutting step in the preparation of thecavity?

1. Finishing the tooth walls2. Finishing the dentin walls3. Finishing the enamel walls4. Finishing the occlusal walls

Stubborn particles of debris may be removed from acavity preparation by which of the followingmaterials?

1. Alcohol2. 2 x 2 gauze3. 4 x 4 gauze4. Small cotton pellet

What two materials are used in a cavity preparationto protect the pulp?

1. Bases and resins2. Fluoride and amalgam3. Bases and cavity liners4. Cavity liners and amalgam

What material is used to seal the dentinal tubules tohelp prevent microleakage in a cavity preparation?

1. Bases2. Cements3. Amalgam4. Cavity varnish

17

3-68. When the dentist is making the final adjustment tothe matrix, which of the following steps should thedental assistant be preparing?

1. Changing the bur in the hand piece2. Placing the precapsulated amalgam in the

amalgamator3. Charting the completed restoration in the

dental record4. All of the above

3-69. What instrument will the dentist use to bring anyexcess mercury from the amalgam to the top of therestoration?

1. Carver2. Hatchet3. Burnisher4. Mouth mirror

3-70. What BUMED instruction contains information onthe Mercury Control Program?

1. 6260.302. 6260.203. 6360.304. 6360.20

3-71. Which of the following materials may be used toremove any roughness or overhang of an amalgamrestoration in the proximal area?

3-72. Which of the following composite resins is availablefor use in operative dentistry?

1. Hybrid2. Microfilled3. Macrofilled4. All of the above

3-73. What composite shade will appear if the toothbecomes dehydrated?

1. Darker2. Lighter3. Transparent4. Chalky white

3-74. What type of matrix may be placed on the toothbefore the acid etching procedure begins?

1. Wood2. Metal3. Rubber4. Celluloid

3-75. Glass ionomer cement will bond directly with whichof the following tooth surfaces?

1. Enamel2. Dentin3. Cementum4. All of the above

1. Dental tape2. Dental floss3.4.

Metal filing stripPlastic filing strip

18


Textbook Assignment: "Oral Surgery Assistance," chapter 5, pages 5-1 through 5-27; and "Periodontic Assistance," chapter 6-1through 6-17.

4-1. Which of the following terms is used to describe theextraction of teeth in oral surgery?

1. Exodontics2. Endodontics3. Extrodontics4. Yankodontics

4-2. Which of the following Standard Forms should be usedwhen informed consent is required?

1. 5152. 5223. 5324. 542

4-3. To control pain and anxiety, which of the followingbasic levels of anesthesia are administered?

1. Local, unconscious sedation, and general2. Conscious sedation, general, and infiltration3. General, local, and gas4. General, local, and conscious sedation

4-4. Which of the following oral surgery procedures are thethree types of tooth extractions?

1. Simple, uncomplicated, impacted2. Exostosis, simple, complicated3. Impacted, simple, complicated4. Complicated, simplex, impacted

4-5. Which of the following types of extraction involvesremoval of a tooth that is partially or completelycovered by bone and soft tissue?

1. Simple2. Impacted3. Complicated4. Uncomplicated

4-6. Which of the following types of extraction involvesremoval of a tooth or root that does not require boneremoval or sectioning?


4-7. Which of the following types of extraction involvesremoval of a tooth or root that requires surgicalsectioning and/or bone removal?


4-8. What type of oral surgery procedure involves thecontouring of the alveolar structures?

1. Exostosis2. Frenectomy3. Osteotomy4. Alveoloplasty

4-9. What oral surgery procedure will be performed on apatient who has a fractured mandible or maxilla?


4-10. What oral surgery procedure will involve the surgicalremoval of bony growths projecting past the normalcontour of a bony surface?


19

4-11. What oral surgery procedure involves the removal of amalattached facial or lingual frenum?


4-12. What Standard Form does a dentist submit to an oralhistopathology center for a submission of an oralbiopsy?

1. 5052. 5103. 5134. 515

4-13. Which of the following oral surgery proceduresinvolves the removal of devitalized portions of bonethat have separated from the adjacent bone?

1. Implant2. Sequestrectomy3. Incision and drainage4. Foreign body removal

4-14. Which of the following conditions occurs when a bloodclot does not form or dislodges from a tooth socket?

1. Exostosis2. Alveoloplasty3. Alveolar osteitis4. Granulation osteitis

4-15. Which of the following tongue and cheek retractors iscommonly used in oral surgery procedures?

1. Fraizer2. East west3. Minnesota4. Curved Kelly

4-16. In addition to beaver style, which of the followingsurgical scalpel handles is commonly used in oralsurgery procedures?

1.# 32. #103. #114. #12

4-17. Which of the following silk suture materials is mostcommonly used for the oral mucosa?

1. 1-02. 2-03. 3-04. 4-0

4-18. Tissue forceps have two small sharp pointed extensionsthat form which of the following shapes when in theclosed position?

1. W2. X3. Y4. Z

4-19. What type of surgical instrument is sharp andspoon-shaped and used to clean out infected cavities inbone and remove debris from the tooth sockets?

1. Malar2. Rongeur3. Chisels4. Curettes

4-20. What type of surgical forceps is used to trim projecting,uneven, or overhanging bone?

1. #652. #2863. Rongeur4. Hawkbill

4-2 1. What type of surgical elevator is used to separate a boneor tooth from the fibrous membrane?

1. Spade2. Minnesota3. Periosteal4. Straight root

4-22. What type of straight root elevator has the smallestworking end?

1. 7 32. 9 23.34S4. 301

20

4-23. In which direction are the beaks of maxillary forcepsangled from the curvature of the handles?

4-29. When performing surgery on the maxillaryarch, what degree angle should the patient’salatragus line be to the floor?

1. Away2. Same3. Vertical4. Horizontal

1. 352. 453. 554. 65

4-24. In what direction are the beaks of mandibular forcepsangled from the curvature of the handles? 4-30. At least how many minutes should it take to

complete a surgical scrub of a patient’s face?1. Same2. Away3. Vertical4. Horizontal

1. 12. 23. 34. 4

4-25. What letter-shaped forceps are used on the mandibulararch? 4-31. You should scrub at least how many inches

above your elbow when performing a surgical1. L and I scrub of your hands?2. C and S3. C and L4. S, I, and Z

4-26. What letter-shaped forceps are used on themaxillary arch?

1. 12. 23. 34. 4

4-32.1. L and I2. C and S3. C and L4. S, I and 2

When performing gloving procedures, whatmember of the surgical team opens thepackages of disposable sterile gloves?

4-27. What type of surgical equipment is used toprotect the dentist and the patient from thelong shaft of surgical burs?

1. Dentist2. Scrub assistant3. Surgical assistant4. Circulating assistant

4-33.1. Bur rings2. Bur guards3. Bur holders4. Bur wrappers

When following the rules of the aseptictechnique, in what position should you alwayskeep your hands?

4-28. On what type of surgical stand will thecirculating assistant place the surgery tray?

1. Above your head2. Above your waist3. Above your heart4. Above your shoulders

1. Oval2. Nayo3. Tayo4. Mayo

4-34. To control bleeding, what is the minimumamount of minutes a pressure pack may remainin place?

1. 102. 203. 3 04. 4 0

21

4-35.

4-36.

4-37.

4-38.

4-39.

4-40.

If adequate healing has taken place, nylon orsilk sutures may be removed after how manyminimum days following surgery?

1. 12. 23. 34. 4

Which of the following supportive structuresis/are part of the periodontium?

1. Gingiva2. Alveolar bone3. Periodontal ligaments4. All of the above

Damage to the periodontium is called whattype of disease?

1. Gingival2. Periapical3. Periodontal4. Periodontalism

The primary function of periodontal treatmentis the elimination of what type of periodontalcondition?

1. Pockets2. Calculus3. Gingivitis4. Malposed teeth

An inflammatory disease confined to thegingiva is termed as what type of periodontalcondition?

1. Bone loss2. Gingivitis3. Periodontitis4. Marginal periodontitis

Inflammatory diseases that damage the deepsupporting structures of the periodontium areclassified as what type of periodontalcondition?

1 .Bone loss2. Gingivitis3. Periodontitis4. Marginal periodontitis

4-41.

4-42.

4-43.

4-44.

4-45.

4-46.

For successful periodontal treatment, a patientmust be willing to accept which of thefollowing conditions?

1. Treatment2. Requirements3. Good oral hygiene4. All of the above

Periodontal treatment is contraindicated if apatient displays which of the followingresponses?

1. Negative attitude2. Positive attitude3. Good flossing technique4. Good brushing technique

On what NAVMED form are the results of aperiodontal examination charted?

4. 6630/4

What are the most important findings in theperiodontal examination?

1. 6600/12. 6600/23. 6630/3

1. Probing depths2. Mobility of teeth3. Amount of bleeding4. Brushing and flossing techniques

What color pencils are used on the frontsection of the Periodontal Chart?

1. Blue and red only2. Black and yellow3. Blue, red, and orange4. Black, blue, and red

When performing a periodontal examination,how many total measurements on each toothwill a dentist make when measuring for pocketdepth?

1 .12.23.64.8

22

4-47. How many total classes are used to describeand record mobility?

4-53. Sickle scalers with contra-angled shanks aredesigned to adapt to which of the followingteeth in the mouth?

1. 12. 23. 34. 4

1. Anterior2. Posterior3. Both 1 and 2 above4. Distal-facial

4-48. When using a periodontal probe, an angledshank places the working end at about whatdegree of an angle in relation to the handle?

4-54. What are the two basic types of curettes?

1. Sickle and jacquette2. Universal and McCall’s3. Universal and Columbia4. Universal and area specific

1. 1 52. 4 53. 5 54. 6 5

4-55. Which of the following materials is/are used tomake special scalers for cleaning theabutments of dental implants?

4-49. The scored millimeter markings on aperiodontal probe can range from whatminimum to what maximum increments?

1. Plastic only2. Nonmetallic only3. Both 1 and 2 above4. Gutta-percha

1. 1 to 82. 2 to 83. 1 to 94. 1 to 10

4-56. A periosteal elevator is designed to retractwhat type of tissues?4-50. A furcation probe is designed to help

determine the extent of what type of bone loss?1. Hard2. Delicate3. Oral mucosa4. Periodontal

1. Apical2. Vertical3. Horizontal4. Interradicular

4-51. Which of the following actions is the objectiveof scaling calculus from the tooth surface?

4-57. Periodontal knives are designed to make initialincisions for which of the following types ofperiodontal procedures?

1. Shaving2. Removing3. Releasing4. Peeling

1. Gingivoplasty and gingivectomy2. Osseous and root amputations3. Periodontal flaps4. Hemisection

4-52. Sickle scalers with straight shanks are designedto adapt to which of the following teeth in themouth?

4-58. Periodontal surgery curettes and sickles aredesigned to remove what type of tissue?

1. Anterior 1. Hard2. Posterior 2. Delicate3. Both 1 and 2 above 3. Gingival4. Distal-facial 4. Granulation and fibrous

23

4-59. To recontour the bone during periodontalsurgery, the dentist may use which of thefollowing periodontal surgery instruments?

1. Rongeurs and files2. Rongeurs and curettes3. Chisels, hoes, and files4. Chisels, curettes, and sickles

4-60. Which, if any, of the following advantagesoccurs when using the electrosurgeryapparatus?

1. Painless surgery2. Control of bleeding3. Control of tissue removal4. None of the above

4-61. Which of the following are the two types ofocclusal equilibration?

1. Complete and limited2. Finished and partial3. Uncompleted and unlimited4. Unrestricted and unlimited

4-62. When the dentist is performing an occlusaladjustment, which of the following materialsis/are used to wipe off the marks and keep theteeth dry?

1. Sterile gloves2. Gauze sponges3.Cotton pellets4. All of the above

4-63. What type of sensitivity is reduced oreliminated when performing rootdesensitization procedures?

1.Nerve2.Enamel3. Cementum4.Dentinal

4-64.

4-65.

4-66.

4-67.

4-68.

A periodontal flap is a technique used in anattempt to correct what type of defect?

1. Bone2. Osseous3. Gingival4. Tuberosity

Osseous lesions will appear interproximally aswhat shaped defect?

1. Flat2. Grape3. Saucer4. Triangular

What type of treatment is required before aroot amputation?

1. Operative2. Endodontic3. Oral Surgery4. Prosthodontic

Most periodontal dressings will stay in placefor how many maximum amount of daysbefore removal?

1. 12. 23. 34. 7

What type of appearance will have a sharpcutting edge that does not reflect light?

1. Line2. Glare3. Double line4. Rounded line

4-69. What type of appearance will have a dull edgethat reflects light?

1. Line2. Glare3. Double line4. Square line

4-70. What type of sharpening stone, if any, is fairlycourse, cuts rapidly, and is used primarily forinitial sharpening of very dull instruments?

1.Arkansas2.White3.Ruby4.None

24

4-71.

4-72.

What type of sharpening stone, if any, has afine grit and is used to attain a sharp edge?

1. Arkansas2. White3. Ruby4. None

Which of the following number of cuttingedges require sharpening on a Kirkland knife?

1. 12. 23. 34. 4

4-73. Which of the following number of cuttingedges require(s) sharpening on McCallcurettes?

1. 12. 23. 34. 4

4-74. Which of the following number of cuttingedges require(s) sharpening on sickle scalers?

4-75.

1. 12. 23. 34. 4

Which of the following number of cuttingedges require(s) sharpening on a hoe scaler?

1 . 12. 23. 34. 4

25


Textbook Assignment: "Endodontic Assistance," chapter 7, pages 7-1 through 7-16; and "Prosthodontic Assistance," chapter 8, pages8-1 through 8-35.

5-1.

5-2.

5-3.

5-4.

5-5.

5-6.

Endodontic treatment is also known as what type oftherapy?

1. Pulp2. Nerve3 Root canal4. Apicoectomy

What is the primary purpose of endodontics?

1.2.3.4.

To relieve painTo extract teethPreserve the pulp and periapical tissuesTreatment of diseases of the pulp andperiapical tissues

If injured pulpal tissue undergoes necrosis, which ofthe following situations occur?

1. Pulp dies2. Pulp lives3. Pulp is transplanted4. Pulp is irritated

Which, if any, of the following is NOT a cause of aninjured dental pulp?

1. Traumatic blows2. Thermal irritation3. Chemical irritation4. None of the above

The diagnosis of pulp and periapical conditionsoccur in what phase of treatment?

1. During the treatment only2. After the treatment only3. Both 1 and 2 above4. Before the treatment

Signs of discolored teeth, crown fracture, and grosscaries can be found during which of the followingprocedures?

1. Dental history exam2. Clinical examination3. Thermal sensitivity test4. Percussion test

5-7.

5-8.

5-9.

5-10.

5-11.

5-12.

The presence of a dark area on a radiographsurrounding the apex of the root is also referred toby what other term?

1. Dental caries2. Periodontal abscess3. Type I fracture4. Radiolucency

The sensation of a slight tingling or warm feeling isfelt during which of the following diagnostic tests?

1. Cold test2. Percussion3. Pulp testing4. Selective anesthesia

During a cold test, if the pulp is inflamed, thepatient will experience what type of sensation to thecold?

1. Sharp2. Tingling3. Lingering4. Violent pain

If a patient experiences no response to a heat or coldtest, the pulp is considered to have which of thefollowing conditions?

1. Vital2. Mobile3. Inflamed4. Necrotic

A percussion test determines which of the followingconditions?

1. Periapical inflammation2. Vitality3. Pulpitis4. Mobility

What type of application is used for palpation?

1. Anesthesia2. Pulp tester3. Mouth mirror4. Finger pressure

26

5-13.

5-14.

5-15.

5-16.

5-17.

5-18.

5-19.

Which of the following tests involves the movementof tooth between the handles of two instruments?

1. Mobility2. Palpation3. Percussion4. Transillumination

Transillumination is most effective on which of thefollowing teeth?

1. Anterior2.3.

PosteriorDeciduous

4. Permanent

Placing a pulp cap over a layer of remaining dentinis referred to by what term?

1. Pulpotomy cap2. Direct pulp cap3. Partial pulp cap4. Indirect pulp cap

What type of therapy consists of internaldebridement, cleaning, shaping, and permanentfilling?

1. Pulpotomy2. Pulpectomy3.4.

Root canalApicoectomy

The surgical removal of the pulp chamber is knownby which of the following terms?

1. Pulpectomy2. Pulpotomy3.4.

ApicoectomyIncision and drainage

What is the procedure called when the entire pulp isremoved?

1. Completed Pulpotomy2 . Pulpal removal3 .4 .

PulpectomyApicoectomy

What type of acute abscess requires an incision anddrainage to eliminate infection along withendodontic treatment?

1. Periradicular2. Periodontal3.4.

PulpalPeriapical

5-20.

5-21.

5-22.

5-23.

5-24.

5-25.

5-26.

A broken instrument lodged in the root canalpreventing a complete filling will require what typeof treatment?

1. Instrumentectomy2. Apicoectomy3. Pulpotomy4. Pulpectomy

What method is used to seal the apical end of theroot canal in conjunction with an apicoectomy?

1. Periapical curettage2. Calcified root canal filling3.4.

Root amputationRetrograde filling

Paper points are used in endodontics for which ofthe following reasons?

1. To deliver medications to the canal2. To dry out the root canals3.4.

To measure working distanceTo remove the pulp

Which of the following is NOT an advantage forusing gutta-percha points for root canal restorativematerials?

1. Poor heat conductor2. High thermal expansion3.4.

RadiopaqueShrinks when used with a solvent

Endodontic explorers are used for which of thefollowing reasons?

1. Locate canal openings2. Lateral condensation3. Enlarge pulp canal4. Pulp removal

What is the major difference between endodonticand cotton forceps?

1. Size2. Made of rubber3. Ends are grooved4. Angle of the working end

What symbol is used to identify barbed broaches?

1. Six-pointed star2. Eight-pointed star3. Ten-pointed star4. Six-rings

27

5-27.

5-28.

5-29.

5-30.

5-31.

5-32.

5-33.

Which of the following instruments is used toenlarge the pulp canal?

1. Broaches2. Endodontic explorer3. Paper points4. Reamers

Which of the following are types of root canal files?

1. G and H2. H and F3. H and K4. K and J

What is the number of the Gates-Glidden drill thatis rarely used?


What are the two types of endodontic condensers?

1. Plugger/woodsen2. Woodsen/vertical condenser3. Plugger/spreader4. Spreader/woodsen

Which of the following materials prevents injury tothe apex of the root and periapical tissues?

1. Rubber dam2. Lentulo spiral3. Stops4. K files

What type of rubber dam frame saves valuable timewhen exposing radiographs?

1. Metal2. Young's3. U-shaped4. Radiolucent

Which of the following solutions is most frequentlyused for irrigation of the root canal?

1. Sterile saline2. Hydrogen peroxide3. Root canal solution4. Sodium hypochlorite

5-34.

5-35.

5-36.

5-37.

5-38.

5-39.

5-40.

The length of an endodontic treated tooth ismeasured using which of the following rulers?

1. Standard2. Endodontic millimeter3. Endodontic centimeter4. Endodontic inch

How are rubber stops placed on files and reamers?

1. Right angle2. Oblique angle3. Vertical angle4. Horizontal angle

What portion of the master cone is coated withcement?

1. Apical first2. Apical second3. Apical third4. Apical fourth

The excess length of the gutta-percha is removed bywhich of the following instruments?

1. Scalpel2. Heated file3. Iris scissors4. Heated instrument

Prosthodontic treatment is concerned primarily withreplacing missing teeth with what type of substitute?

1. Plastic2. Permanent3. Artificial4. Non-permanent

Interacoronal restorations fit on what portion of atooth?

1. Around2. Bottom3. Into4. Onto

Extracornal restorations fit on what portion of atooth?

1. Around2. Bottom3. Into4. Onto

28

5-41.

5-42.

5-43.

5-44.

5-45.

5-46.

5-47.

Artificial crowns cover what coronal portion of thetooth?

1. Half2. Quarter3. One third4. More than half

The part of the post that protrudes from the rootcanal is called what type casting?

1. Veneer2. Anchor3. Core4. Fixed

A pontic suspended from only one retainer is held inplace by which of the following methods?

1. Hanging2. Connecting3. Suspension4. Cantilevered

A rigid, temporary restoration that replaces missingteeth is classified as what type of prosthesis?

1. Interim fixed partial denture2. Fixed partial denture3.4.

Partial dentureFixed splint

What type of removable prosthesis replaces all ofthe natural teeth in an arch?

1. Round-house2. Complete denture3. Maryland bridge4. Partial denture

What type of partial denture is made for insertionimmediately following the surgical removal ofnatural teeth?

1. Surgical2. Temporary3. Removable4. Immediate

Which of the following dental alloys is NOT aclassification type?

1. Precious2. Semiprecious3.4.

SeminobleNonprecious

5-48.

5-49.

5-50.

5-51.

5-52.

5-53.

5-54.

Alginate is also known as which of the followingimpression materials?

1. Irreversible hydrocolloid2. Reversible hydrocolloid3. Synthetic hydrocolloid4. Silicone hydrocolloid

What specific time period will Type-I fast setalginate gel?

1. 1 to 2 minutes2. 2 to 3 minutes3. 3 to 4 minutes4. 4 to 5 minutes

Which of the following consistency types is NOT arubber impression material?

1. Light bodied2.3.

Medium bodiedRegular bodied

4. Heavy bodied

Which, if any, of the following material types isNOT an impression material?

1. Polysulfides2. Silicones3. Polyethers4. Collodion

Dental plaster will have a final set completed withinapproximately how many minutes?

1. 1523.

3045

4. 60

A dental stone mixture has an initial setting time ofhow many minimum and maximum minutes?

1. 29 to 362. 22 to 293. 15 to 224. 8 to 15

What type of dental wax is used on impressiontrays?

1. Sticky2. Utility3. Baseplate4. Bite registration

29

5-55. What type of acrylic is used to make customizedimpression trays?

1. Tray2. Repair3.4.

OrthodonticCrown and bridge

5-56. Separating media prevents which of the followingactions?

1. Tooth distortion2. Tooth separation3. One material from bonding to another material4. One material from separating to another

material

5-57. Tray adhesive ensures that impression materialaccomplishes which of the following results whentaking impressions?

1. Material stays in the tray when removed fromthe mouth

2. Material stays in the mouth when the tray isremoved

3. Material separates when removed from thetray.

4. Tray separates when removed from thematerial

5-58. The alcohol torch is used for which of the followingprocedures?

1. Smoothing wax surfaces2. Setting teeth3. Waxing4. All of the above

5-59. Which type of alcohol is the best choice fuel for thealcohol torch?

1. Isopropyl2. Methyl3. Denatured4. Rubbing

5-60. The dental cast trimmer is used to perform which ofthe following procedures?

1. Cutting cast in half2. Cutting off teeth3. Trimming teeth4. Trim and contour

5-61.

5-62.

5-63.

5-64.

5-65.

5-66.

5-67.

The two basic types of impression trays availablefor use are which of the following?

1. Maxillary and mandibular2. Stock and custom3. Disposable and rimlock4. Rubber and plastic

The mixing bowl is used to mix which of followingdental materials?

1. Rubber base2. Alginate only3. Dental stone only4. Both 2 and 3 above

The pneumatic curing unit has a normal curing timeof (a) how many minutes and (b) at what psi?

1. (a) 60 (b) 502. (a) 45 (b) 353. (a) 30 (b) 204. (a) 20 (b) 10

The vacuum adapter is used for the rapid fabricationof which of the following prosthetic appliances?

1. Custom trays2. Maryland bridges3. Complete dentures4. Fixed partial dentures

Which, if any, of the following materials does adental vibrator move when pouring a cast?

1. Rubber base and alginate2. Dental plaster and stone3. Treatment liners and resins4. None of the above

An impression tray should have how manymillimeters of space between the tray, teeth, and softtissues when tried in?

1. 1 to 22. 2 to 33.4.

3 to 44 to 5

Where should your index finger be placed on thetray when breaking the seal formed by the alginatematerial on a maxillary impression?

1. Along the posterior border2. Along the facial border3.4.

Along the lingual borderAlong the lateral border

30

5-68. When mixing dental stone for a cast, in which ordershould the materials be mixed?

1. Gypsum to powder2. Powder to gypsum3. Water to powder4. Powder to water

5-69. At least how many minutes should a first pour castset before making the cast base?

1. 4 52. 3 03. 1 54. 5

5-70. When trimming a dental cast, which area should beground down first?

5-71.

1. Top2. Side3. Bottom4. Back

A custom tray is made on which of the followingtypes of cast?

1. Final2. Diagnostic3. Preliminary4. Prefabricated

5-72. When preparing a cast for a mouthguard, whatmaximum mm thickness should the cast base NOTexceed?

1. 82. 23. 64. 4

5-73. How many inches should the splint material sag on aheated vacuum-forming machine?

5-74.

1. 1 1/2 to 22. 2 1/2 to 33. 3 to 3 1/24. 4 to 4 1/2

When performing a denture base repair, how manycoats of tin foil substitute are painted on the dentalcast?


5-75. Which of the following DD forms is used for dentallaboratory work?

1. 22322. 32223. 23324. 2322

31


Textbook Assignment: "Dental Treatment Room Emergencies," chapter 9, pages 9-1 through 9-8; and "Forensic Dentistry," chapter10, pages 10-1 through 10-26.

6-1.

6-2.

6-3.

6-4.

6-5.

6-6.

6-7.

Which of the following, if any, additional safetyfeatures should be included with dental safetypatient glasses?

1. Tinted lenses2. Side shields3. Safety glasses straps4. None of the above

The normal body temperature of an adult rangesfrom which of the following degrees Fahrenheit?

1. 94 to 992. 96 to 983. 97 to 994. 98 to 101

An adult’s normal pulse rate per minute can rangefrom which of the following beats per minute?

1. 40 to 602. 60 to 803. 80 to 1004. 100 to 120

What artery should you use to take a patient’s pulse?

1. Temporal2. Facial3. Carotid4. Brachial

The minimum blood pressure occurs when the heartcontracts.

1. True2. False

The maximum blood pressure occurs when the heartrelaxes.

1. True2. False

What is the normal blood pressure range for thesystolic reading?

1. 60 to 902. 70 to 1003. 80 to 1104. 90 to 140

6-8.

6-9.

6-10.

6-11.

6-12.

6-13.

What is the normal blood pressure range for thediastolic reading?

1. 60 to 902. 70 to 1003. 80 to 1104. 90 to 140

What is the normal cycle of an adult’s range ofrespiration?

1. 8 to 122. 12 to 153. 15 to 184. 18 to 20

An oxygen tank that provides approximately 78liters of oxygen per minute for one-half hour haswhat cylinder size?

1. B2. C3. D4. E

A victim of respiratory and cardiac arrest mustreceive treatment within how many maximumminutes to prevent irreversible brain damage?

1. 5 to 72. 2 to 33. 3 to 54. 4 to 6

What do the ABC’s of CPR stand for?

1. Airway, Breath, Circumstances2. Airway, Bleeding, Circulation3. Airway, Breathing, Circulation4. Arteries, Bleeding, Condition

What person, if any, in the dental clinic is notrequired to be certified in the healthcare providercourse for CPR?

1. Dentist2. Dental technicians3. X-ray technicians4. None of the above

32

6-14.

6-15.

6-16.

6-17.

6-18.

6-19.

6-20. What is the treatment for angina pectoris?

What CPR certification course teaches non-healthcare personnel?

1. Heartsaver course2. CPR "E" course3. CPR "A" course4. Healthcare provider course

The hand-operated resuscitator allows the operatorto do which of the following actions?

1. Perform proper chest compressions2. Perform abdominal thrust3. Rescue breath for a patient without

mouth-to-mouth contact4. Both 2 and 3 above

At least how many rescuers are recommended tooperate a hand-held resuscitator?

1. 12. 23. 34. Both 2 and 3 above

Oxygen tanks are always painted what color?

1. Brown2. Blue3. Green4. R e d

What is the normal flow rate in liters per minuteWhat is the normal flow rate in liters per minutewhen oxygen is administered?when oxygen is administered?

1. 52. 63. 74. 8

Which of the following safety precautions foroxygen supply is false?

1. Close all valves when the cylinder is not in use2. Always stand to the side of the cylinder3. No smoking in any area where oxygen is

stored or in use4. Always secure cylinder(s) on their side in a

proper storage rack

1. Chest compressions and rescuing breathing2. Place patient in a 45-degree angle (sitting up)3. Administer 100 percent oxygen and one

nitroglycerin tablet sublingually4. Both 2 and 3 above

6-21. What is the maximum amount of nitroglycerintablets a patient may receive in a 15-minute period?

1. 62. 23. 34. 5

6-22. A patient who shows the signs of restlessness,anxiety, weakness, anxiousness, dull expression, anddisorientation is suffering from which of thefollowing conditions?

6-23.

1. Shock2. Hypoglycemia3. Hyperventilation4. Syncope

A patient who shows the signs of cyanosis,wheezing, coughing, and difficulty in breathing issuffering from what, if any, medical emergency?

6-24.

1. Seizures2. Shock3. Asthma attack4. Hyperventilation

When treating syncope, you should place thepatient’s feet in what position?

1. Six o’clock2. 15° angle down3. Trendelenburg style4. 15° angle up

6-25. Anaphylactic shock usually occurs what period oftime after the victim has been exposed?

1. Seconds2. Minutes3. Hours4. Days

6-26. After a patient has been anesthetized orpremedicated with a drug, you should performwhich of the following actions?

1. Perform basic life support2. Activate the clinic's emergency response team3. Place patient in Trendelenburg's position4. Observe patient and watch for signs of an

adverse reaction

33

6-27. Forensic dentistry is defined as the branch offorensic medicine that applies to which of thefollowing entities?

1. Dental knowledge to the Federal court system2. Dental knowledge to civil and criminal

problems3. Dental knowledge to bite mark analysis4. Dental knowledge of insurance companies

6-28. The primary reason the Navy has been directed toestablish forensic dental identification capability isto assure which of the following requirements?

1. To assist in the identification of humanremains

2. For any inheritance of the deceased's next ofkin

3. For any claim of insurance held by the victim4. To comply with State and Federal laws

6-29. Without positive identification, any inheritance andlast will and testament could be delayed for howlong?

1. Indefinitely2. Until the person is declared legally dead3. Up to 7 years4. Both 2 and 3 above

6-30. A graphic example of the psychological aspect ofthe need for forensic identification to the next of kinwas experienced in which, if any, of the followingsituations?

1. Legal issues2. Medical issues3. Vietnam "missing in action"4. None of the above

6-31. Which of the following body characteristics is themost commonly used method to identify anindividual?

1. Scars2. Tattoos3. Deformities4. Visual recognition

6-32. For many reasons, tattoos should be used as aprimary means for positive identification.

6-33. In the military, what type of personal item is used tospecifically assist in identifying an individual?

1. Government credit card2. Command name tags3. Passports4. Dog tags

6-34. In a court of law, which of the following proofs ofidentity provides an acceptable positive identity of adeceased individual?

1. Skeletal remains2. Distinctive jewelry3. Drivers' license4. Tattoos

6-35. Of all the methods of ID, which of the following isthe best known?

1. DNA analysis2. Fingerprints3. Personal effects4. Dental identification

6-36. Fingerprint ID is always acceptable in a court oflaw.

1. True2. False

6-37. DNA analysis is also known by which of thefollowing terms?

1. DNA identification2. DNA evidence3. DNA marking4. DNA fingerprinting

6-38. Dental identification is a definitive means ofpositive identification of unknown human remains.

6-39.

1. True2. False

Dental evidence tends to survive much better thanwhich of the following other evidences?

1. Facial characteristics2. Soft tissue3. Fingerprints4. All of the above

1. T r u e2. False

34

6-40. Teeth that are unprotected by the soft tissues of thecheeks and lips, in rare instances, can be destroyedby fire if the minimum temperature exceeds whichof the following degrees Fahrenheit?

1. 2502. 5003. 7504. 1000

6-41. Silver amalgam will resist temperaturesmaximum degree Fahrenheit?

up to what

1. 16002. 17003. 18004. 1900

6-42. Given sufficient data, it is possible that two sets ofteeth can be identical.

1. True2. False

6-43. In an antemortem database, radiographs areconsidered what type of evidence?

1. Error free2. Material3.4.

HardSoft

6-44. Which of the following problems may delay thefinal determination of an identification?

1. Illegible dental records2. Adequate dental radiographs3.4.

Adequate chartingAll of the above

6-45. When does postmortem identification occur?

4. Before death

1. During an annual examination2. During a separation examination3. After death

6-46. When evaluating the post and antemortem records,discrepancies may be classified in what, if any, twobroad categories?

1. Relative and comparison2. Relative and absolute3.4.

Absolute and comparisonNone

6-47.

6-48.

6-49.

6-50.

6-51.

Antemortem dental records detail dental conditionsduring which of the following times?

1. Before death2. After death3. Both 1 and 2 above4 . At any time

Relative discrepancies between the antemortem andthe postmortem dental exam findings can beexplained by which of the following methods?

1. Exact match2. Human error3.4.

Radiographic comparisonContinued dental treatment

Which of the following items would best representthe person if the remains cannot be those of theindividual under consideration?

1. Radiographic comparison2. Absolute inconsistencies3.4.

Relative discrepanciesExact match

What type of comparison would the postmortem andantemortem radiographs show if a tooth restorationwas the same in both?

1. Similarity2. Relative discrepancy3.4.

Absolute inconsistencyExact match

What is the final and most important step in thedental ID process?

1. Classification2. DNA analysis3.4.

ComparisonsCharting

A. P o s i t i v ei d e n t i f i c a t i o n

B. P o s i t i v ei d e n t i f i c a t i o n b ycha r t ing on ly

C. Cons i s t en t w i thD. ExclusionE. Uniden t i f i ed

Figure 6-A.—Classification of the dental identification.

35

IN ANSWERING QUESTIONS 2-52 THROUGH 2-56,SELECT FROM FIGURE 6-A THE CLASSIFICATIONUSED TO ESTABLISH IDENTITY. YOU WILL USEALL THE CLASSIFICATIONS IN FIGURE 6-A ONLYONCE.

6-52. The remains cannot be those of the suspectindividual.

1. B2. C3. D4. E

6-53. The ID is based solely on the written dental record.

1. A2. B3. C4. D

6-54. No sufficient evidence to determine the identity ofthe individual.

1. B2. C3. D4. E

6-55. The forensic dentist is positive they have determinedthe ID of the individual.

1. A2. B3. C4. D

6-56. A good probability that the remains are those of thesuspect person.

1. A2. B3. C4. D

6-57. Which of the following elements is part of thecommand/support?

1. Photographic2. Personal effects3. Medical radiology4. Graves registration

6-58.

6-59.

6-60.

6-61.

6-62.

6-63.

6-64.

Which of the following elements is part ofidentification?

1. Dental2. Mortuary affairs3. Recovery/transportation4. Security

The dental team leader performs the same tasks aswhich of the following?

1. Dental registrar2. Public affairs officer3. Operations chief4. Oral surgeon

Which of the following dental team members willexpose the maxilla and mandible for anexamination?

1. Radiologist2. Oral surgeon3. Dental technician4. Dental team leader

Who protects all dental evidence coming into andgoing out of the dental area?

1. Security2. Dental registrar3. Dental team leader4. Inprocessing officer

Problems with access to dental structures arise mostcommonly from which of the followingcircumstances?

1. Plane crash victims2. Intact full body remains3. Partial body remains4. Chemical exposure victims

At least how many minutes is normally required toexpose a complete series of postmortem remains?

1. 2 02. 2 53. 3 04. 6 0

What type of x-ray developer is used to processforensic radiographs?

1. Large2. Small3. Manual4. Any type

36

6-65.

6-66.

6-67.

6-68.

6-69.

6-70.

When mounting forensic periapical or bitewing X-rays, which direction should the raised dot face?

6-71. What is the last section in the dental forensic IDprocess?

1. Facing in2. Facing out3.4.

Both 1 and 2 aboveFacing sideways

For film accountability, what does a green opaquefilm in the mount represent?

6-72.

1. Antemortem/Postmortem Records Comparison2. Antemortem Records Comparison3. Postmortem Records Comparison4. X-ray Comparison

What form summarizes the ID data during theantemortem/postmortem comparison?

1. No radiograph is available for a particular area2. A faulty X-ray machine3. Not enough kVps4. Developer problems

What is the first step you do when you areperforming a dental postmortem examination?

6-73.

1. Antemortem/postmortem summary sheet2. Forensic summary sheet3. Dental identification summary sheet4. CAPMI DOD summary sheet

Who is responsible to sign a forensic identificationcase out as a positive ID?

1. Dental X-rays 1. Identification Center chief2. Dental charting 2. Pathologist Center chief3.4.

Entering victim in computer system 3.4.

Dental team leaderGentle cleaning of the dental remains Any dentist

Postmortem charting should be done using which ofthe following item (s)?

6-74. The antemortem composite dental record should beplaced in the uncompleted file only if the fulldentition was recovered.

1. Pen2. #2 pencil only3.4.

Special postmortem blue pencilBoth 2 and 3 above

6-75.At least how many members of the antemortemdental record staff should review each compositedental record?

1. True2. False

Most equipment and supplies for forensic operationcan be maintained in which of the following typesof storage areas?


1. Large box2. Mobile dental van3. Large supply locker4. Medium-size tackle box and canvas bags

What does "CAPMI" stand for

1. Computer Antemortem Program ManagementInformation

2. Computer and Postmortem ManagementIntelligence

3. Computer Assisted Postmortem Identification4. Computer Antemortem Program Management

Information

37

Documents

Dental Technician, Volume 2