CONTROL OF MOISTURE

Introduction

The production of absorbed dryness by the exclusion of mouth sections

and humidity from the operative field is essential to the correct performances of

most operative procedures.

The term oral environment refers to the following items which require

proper control to prevent them. From interfering with the execution of any

restorative procedures

1. Saliva

2. Moving organs, ie tongue

3. Lips & Check

4. The periodontium

5. The contacting teeth and restoration

6. The sulci, floor of the mouth and palate

7. Respiratory moisture

With six major salivary glands producing saliva there must be a way to

evacuate it either mechanically by the patient own swallowing mechanism or

by chemically reducing its secretion.

All these procedures are important because saliva may obstruct proper

vision and access interfere with and detrimentally affect the setting and

adaptability of restorative materials, modify or regale the effect of medicaments

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and may be sprayed with rotary instruments to propagate infection in the office

atmosphere.

1. Moisture Control

Moisture control refers to excluding sulcular fluid, saliva and gingival

bleeding from the operative field.

It also refers to preventing the handpiece spray and restorative debris

from being swallowed or aspirated.

The advantages of isolation are

1. Dry clean operating field

2. Access and visibility

3. Improved properties of dental materials

4. Protection of patient and operator

5. Operating efficiency

Isolation of the operative fields involves several conceptual elements

1. Moisture control

2. Retraction

3. Harm prevention

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2. Retraction and Access

The details of the restorative procedures cannot be managed without

proper retraction and access. Thus provides maximal exposure of the operative

site. It involves maintaining mouth opening and depressing or retracting the

gingival tissue tongue lips and check.

The rubber dam, mouth props, high volume evacuators, absorbants and

retraction cord are used.

Harm prevention

An axiom taught to every member of the health profession is do not

harm. An important consideration of isolating the operating field is preventing

the patient from being harmed during the operation. Excessive saliva and hand

piece spray can alarm the patient. Small instruments or debris can be

swallowed. As with moisture control and retraction. The dam, section devices

and absorbants play a role in harm prevention. Harm prevention is provided as

such by the nannee in which these devices are used as by the devices

themselves.

Absorbants and Throat shield

Absorbants such as cotton rolls and cellulose wafer are useful for short

periods of isolation example for examination, polishing etc. and also for topical

fluoride application. Absorbants are isolation alternative in cases where rubber

dam application may not be possible.

Especially along with profound anesthesia absorbants provide

acceptable dryness for procedure such as impression taking and cementation.

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The dental assistant mostly has the job of keeping dry cotton rolls in the mouth.

They should be changed when saturated.

Several commercial devices for holding cotton rolls in position are

available. It is generally necessary to remove the holding appliance from the

mouth to change the cotton rolls. This may be inconvenient and time

consuming.

An advantage of cotton roll holders is that the cheeks and tongues are

slightly retracted from the teeth which enhances access and visibility,

For maxillary teeth

A medium sized cotton roll is placed in the adjacent vestibule.

For the mandibular teeth

One medium sized roll in the vestibule and a larger one

between the teeth and tongue.

The teeth are then dried by short blasts from the air syringe.

Cellulose wafers may be used to retract the check and provide

absorbancy.

While removing these absorbants it may be necessary to moisten them

using the all water syringe to prevent removal of the epithelium from the

cheeks, floor of mouth and lips.

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Throat Shields

These are indicated when small instruments are being used or indirect

restoration placed. This is to prevent aspiration or swallowing of restoration.

High volume evacuators and saliva ejectors

When a high speed hand piece is used air water spray is supplied

through the head of the hand piece to wash the operating site and to act as a

coolant for the bur and the tooth. High volume evacuators are perferred for

suctioning water and debris from the mouth because saliva ejectors remove

water slowly and have little capacity for picking up solids.

McWhecter in 1957 showed that evacuators generally would remove 5L

of water in 2 seconds had 75% to 95% pickup of air and water and would

remove 100% of solids during cavity cutting procedures.

A practical test for the efficacy of the evacuator would be to keep it in

150ml of water it should suck it in 1 seconds.

The tips for these may be

1. Plastic Disposable

2. Metallic auto cleavable

The combined use of water spray and high volume evacuator has the

following advantages.

1. Restorative and tooth debris are removed from the operating site.

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2. Access and visibility are improved.

3. No dehydration of oral tissues.

4. Time is saved as the pauses required for patient to spit and wash are

eliminated.

5. Precious metals are readily salvaged.

6. Quadrant dentistry is facilitated.

Precautions

1. The tip should be as near as possible to the tooth to be operated upon

just distal to it.

2. It should not obstruct the operators view.

3. It should not be so close as to direct the water spray away from the

rotary instrument.

Saliva ejectors

Most patient do not require saliva ejectors as salivary flow is greatly

reduced when the operating site is profoundly anesthetized.

The saliva ejector removes saliva that collects on the floor of the mouth.

It is used in conjunctions with sponges cotton rolls and the rubber dam. It

should be placed in an area least likely to interfere with the operators

movements.

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The tip of the ejector must be smooth and made from a non-irritating

material. Disposable inexpensive plastic ejectors that may be shaped by

bending with the fingers are available. The ejector should be placed to prevent

occluding its tip with tissue from the floor of mouth.

Advantages can be summarized as the

A – adequate access and visibility

B – better patient protection and management

C – control of moisture in operating field

D – decreased operating time of rubber dam i.e.

Rubber Dam

There are many ways to isolate an area of the mouth or a tooth so that

restorative services can be performed without interference from soft tissues,

tongue, saliva or other fluids. Various tongue and cheek retruding devices and

suction methods are used. By far the most complete method of obtaining field

isolation is rubber dam.

History:

It is not realized that the rubber dam was first described over 120 years

ago when in March 1864 Dr. Sanford Barnum first explained its use at meeting

of Connecticut Valley Dental Society in New York. He described his delight in

finding such a simple means of saliva control at a time when saliva control was

sedimentary.

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By the following year, the use of rubber dam was warmly recommended

to profession as an indispensable aid to dental practice and 5 years later in 1870

Dr. J.F.P. Hodson described in detail the methods then in current use. Several

aspects of the technique have not changed greatly from that time. The main

difference from current practice being that rubber dam clamps were not

developed and retention of rubber dam was exclusively by means of wedges

and floss silk ligatures. Rubber dam frames were not used and the edges of

rubber were retracted by neck harness and weights suspended from floss silk

ligatures looped around the tooth. Hodson’s article in 1870 details the

construction of seven types of clamps which were designed solely to achieve

improved gingival retraction and were placed without the aid of clamp forceps.

In 1879 the Ainsworth Rubber dam punch was patented the design of

which has changed little in more than a century.

Dr. W. ST Geo Elliotts in 1878 described clamp forceps gripped the

jaws of he clamp rather than the bow. This arrangement allowed the hole in the

rubber dam to be retained on the forcep tips, thus earliest forerunners of idea of

carrying the rubber dam and clamp to mouth simultaneously.

About the same time (1880) the Hickmann “Lipped” clamp was in use

in which the rubber dam sheet was retained on the clamp between two lips on

each jaw. These were earliest forerunner of present day winged design.

Most of the other design of early clamps and forceps were designed to

tension the clamp by engaging the clamp bow. By 1890 some clamps were

being made with holes in jaws to allow the use of forceps similar to stokes

pattern of today.

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A few of early designs have remained popular to the present day e.g.

“Tees Festooned Clamp” designed in 1870. The only feature lacking when

compared to modern version being holes in each jaw. This design was only one

of the first feature jaw which were directed gingivally or “festooned” a

forerunner of the retentive jaw design today.

Colyer gave a detailed account of techniques in use by 1890 and his

description would be quite familiar to today’s practitioner.

Rubber dam frames were described in early 20th century as Metal

Fernauld’s design. More recent designs have taken advantages of developments

in plastics to produce frames which are radiolucent.

By the time G.V. Black produced his seminal text “Operative Dentistry”

in 1908, the use of rubber dam was firmly established. He strongly advocated

its use stating “the rubber dam should be in place for all amalgam fillings, the

same as for gold…. It is as impossible to make a good amalgam filling as it is a

gold (foil) filling with any moisture present”.

The American Dental Association Council on Dental Materials and

Equipments has acknowledged the use of rubber dam stating in 1986 that “The

use of rubber dam to maintain dry field is essential”.

Advantages of Rubber Dam:

The advantages of rubber dam isolation are:-

1) Dry clean operating field:- The operator can best perform procedures such as

caries removal, cavity preparation, restorative procedure in dry field. Teeth

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prepared and restored using rubber dam isolation are less prone to post-

operative problems related to contamination from oral fluid.

2) Access and visibility:- Rubber dam provides maximal access and visibility. It

act as physical barrier to moisture and retracts the soft tissues. Rubber dam

retracts the gingival tissue, lips, tongue and cheek. Rubber dam provides a

dark, non-reflective background in contrast to operating site thus enhances the

visibility.

3) Improved properties of dental materials by preventing the moisture

contamination of restorative materials during insertion and promotes improved

properties of dental materials.

4) Protection of patient and operator:- The rubber dam protects both patient and

operator. It protects the patient from aspirating or swallowing small

instruments and debris associated with operative procedures. It controls the soft

tissues and their protection from injury. The importance of physical barrier

(which rubber dam provides) between patient and operator and patient’s oral

fluids, has recently become more widely recognized due to risk of treating

undiagnosed carriers of HIV and hepatitis B virus. Thus it provides a pleasant

controlled operating environment. (Operative Dentistry 1986; 11:159)

5) Operating Efficiency:- Use of rubber dam enhances operating efficiency and

increased productivity. Patient management is simplified by avoiding need to

rinse the mouth of debris, improving access to operating area, gingival

retraction and control of gingival haemorrhage and surgically clean field.

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Disadvantages:

1) Time consumption and patient objection are most frequently quoted

disadvantages of rubber dam.

2) Minor damages can occur to marginal gingival and cervical cemetnum.

3) Damage to the restorations such as metal crown margins show microscopic

defects following clamp removal and ceramic crown may fracture at margins

if clamps are allowed to grip the porcelain.

4) Accidental aspiration of the clamps

5) Certain conditions which preclude the use of rubber dam

a. Malpositioned teeth

b. Teeth that have not erupted fully to support retain

c. Third molars

d. Excessive coronal tissue loss

6) Patient suffering from respiratory diseases such as asthma may not tolerate

rubber dam if the breathing through nose is difficult.

7) Contact allergy to latex rubber dam sheet. Two cases of contact allergy to

rubber dam have been reported during last 20 years. One manifesting as

angioneurotic oedema with systemic symptoms and other as contact

dermatitis.

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Materials and Instruments:

1. Rubber Dam:

Rubber dam material is made from natural latex rubber. They are

manufactured as,

a) Continuous rolls available in two widths (125 mm or 150 mm)

b) Pre-cut form available in 5 x 5 inch (12.5 x 12.5 mm) or 6 x 6 (15

x 15 mm) square sheets.

Rubber dam material available in assay of colours. Traditionally black rubber

dam was available but now four alternative colour such as green, blue, grey and

natural (translucent) are there.

Thickness: Rubber dam is manufactured in range of five thicknesses.

Grade Thickness

Mm Inch

Thin 0.15 0.006

Medium 0.20 0.008

Heavy 0.25 0.010

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Extra

heavy

0.30 0.012

Special

heavy

0.35 0.014

Shelf life:- Rubber dam material has shelf life of about 9 months at room

temperature. Shelf life will be reduced in warm storage conditions and so a

refrigerator or freezer is best used if prolonged storage is anticipated.

2. Rubber Dam Punch:

Precision instrument with rotating metal table. These instrument are

used to produce the clean cut holes in the rubber sheet through which the teeth

can be isolated.

Two types of holes are made:-

1) Single hole

2) Multihole

1) Single hole:- Available in two sizes. Single hole punches are used mainly for

endodontic isolation and have the advantage of accurate and consistent punch

point to avail alignment. E.g. Dentsply single hold punch.

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2) Multihole:- More versatile and preferred by authors. They allow holes to be

punched in a range of sizes from 0.5 to 2.5mm in diameter by rotation of axil.

E.g. Ivory pattern (Heraeus Kulzer) punch. E.g. Ash or Ainsworth pattern

punch.

Rubber dam punches should be regularly checked for wear and tear. Three

main problems can arise:-

1) Blunting of the sharp cutting edge to the anvil holes, usually due to prolong

use.

2) Damage to the punch point and anvil, as a result of incorrect alignment.

Punching of holes:- The size of hole punched for each tooth depends on several

factors.

a) Whether the tooth is to be clamped or not

b) Cervical diameter of the tooth

c) The elasticity of rubber dam being used

3. Rubber Dam Forceps:

Rubber dam forceps are needed to stretch the jaws of clamp open in a

controlled manner during placement and removal. Several designs of forceps

are available. Three widely used designs are:-

a) ash or stokes pattern

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b) Ivory pattern

c) University of Washington pattern

All three have a sliding ring between the hinge and forceps handles which can

hold the forcep open and so hold the clamp under tension. These three forcep

differ in their tip design.

University of Washington pattern design provide a definite stop which

positively prevent jamming of instrument tip in the hole in clamp jaw.

It also resists tilting of clamp while held in the forceps.

Stokes and ivory pattern have both notched and pointed tips which engages the

holes in clamp jaws.

Ivory pattern forceps (Heraeus Kulzer) have stabilizers that prevent the

clamp from rotating on the beaks.

Stokes type which have notches near the tips of their beaks in which to locate

the holes of rubber dam clamp allow a range of rotation for the clamp so that it

may be positioned on teeth that are mesially or distally angled.

4. Rubber Dam Frame:

Rubber dam frames support the edges of rubber dam and so retract the

soft tissue and improve access to isolated teeth. It can be metal or plastic.

Fernauld’s frame made of metal was first widely used rubber dam frame.

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The metal frames available now are versions of Young’s design. It is ‘U’

shaped open at the top and this allows the upper edge of rubber to fall slightly

forward away from tip of nose.

Young’s frame design also available in plastic preferred particularly for

endodontic radiographs since radiolucent. The rubber dam is retained by series

of pegs around the edges over which the rubber sheet is stretched. Shape of

pegs can be fine spike with relatively sharp points (young’s) or broad pegs with

blunt type (Hygienic or Fernauld’s).

One type of plastic frame (Nygaard Ostby) is a complete circle

supporting the upper edge of rubber.

Rubber dam harnesses retract only the sides of rubber dam. The harness

is attached to vertical edges of rubber sheet by metal clips from which elastic

pass around the back of the head and apply traction to edges of rubber sheet.

E.g. Woodbury retractor.

Dry dam an alternative to frame and harness which consists of small

sheet of rubber set into the centre of an absorbent paper sheet with light elastic

on either side to pass over the ears. This is useful for quickly isolating anterior

teeth but not suitable for molars bleaching due to absorbent nature of paper

surround.

5. Rubber Dam Clamp:

Rubber dam clamp (retainer) is used to anchor the dam to the tooth to be

isolated. The clamp consists of four prongs and two jaws connected by a bow.

Clamps can be divided into two main groups according to jaw design:-

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Bland

o Winged

o Wingless

Retentive

o Winged

o Wingless

Bland: Bland clamps are recognized by the jaws which are flat and points

directly towards each other and are designed to grasp the tooth at or above the

gingival margin and thus causing minimum gingival damage.

Retentive: Retentive clamps have jaws which are directed more gingivally so

that they can grasp the tooth well below the gingival margin.

Winged: The wings are the small flanges on the outer edges of clamp jaws

which are provided to allow the clamp to be retained in dam during placement.

Clamps are made from metal and non-metal

Metal clamps have traditionally been made from tempered carbon steel plated

to resist corrosion and more recently from stainless steel. Dentsply is producing

gold coloured clamp with diamond grit on jaws. Diamond coating is said to

improve retention on the tooth.

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Non-metal clamps made from polycarbonate plastic (Endo Technic).

Advantage of these clamps is that they are radiolucent. Disadvantage – do not

fit the tooth well and are bulky.

To be secure a clamp must fit around the tooth below the level of

maximum crown width (maximum coronal diameter). The points of the jaws of

the clamps must all contact the crown below this level in four areas. Two on

facial surface and two on lingual surface. This is called ‘Four Point Contact’.

The four point contact prevents rocking and tilting of retainer. This is most

easily achieved by selecting those clamps in which the length of clamp jaws

relate to the mesodistal width of the root.

The jaws should not extend the mesial and distal line angles of tooth because,

1) They may interfere with the placement of matrix and wedge

2) Gingival trauma is more likely to occur

3) Complete seal around the anchor tooth is more difficult to achieve

Correct placement of clamp on an anchor tooth is achieved when:-

1) When the bow is to the distal

2) All four points of jaws are in contact with the anchor tooth.

3) The clamp is gripping the crown of the tooth below its maximum coronal

diameter.

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Clamp placement:

Before a clamp is placed on any tooth, the dental floss should be tied. The

dental floss should be 12 inches (30.5 cm) in length. The floss allows retrival of

retainer or its broken parts if they are accidentally swallowed or aspirated.

The clamp is carried to the tooth using clamp forceps.

The clamp engaged in the beaks of forcep by means of holes in the jaws.

The clamp is oriented in the forcep, so that bow will lie to the distal on the

tooth.

Sufficient pressure is used to tension the clamp and retain it on the forcep. The

handle lock maintains the tension in the clamp.

The clamp is placed on the tooth by opening it sufficiently to pass over the

maximum coronal diameter.

The lingual (or palatal) jaw is placed first in contact with lingual surface of the

anchor tooth. Then the clamp tilted bucally until buccal jaw below maxillary

coronal diameter.

The tension of clamp is released slowly as the buccal jaw is placed.

6. Rubber Dam Napkin:

Rubber dam napkin placed between the rubber dam and patient’s skin

and has following advantages:-

a) It prevents skin contact with rubber to reduce the possibility of allergies

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b) Absorbs saliva seeping at the corners of mouth

c) Act as cushion

d) Provides a convenient method of wiping the patient’s lips on removal of dam

7. Lubricant:

A water soluble lubricant applied in the area of punched holes facilitates

the passing of dam septae through the proximal contacts. Rubber dam lubricant

is commercially available but other lubricant such as shaving cream or soap

slurry are satisfactory cocoa butter or petroleum jelly may be applied at the

coroners of patient’s mouth to prevent irritation. These 2 materials are not

satisfactory rubber dam lubricant because both are oil based and cannot be

easily rinsed from dam once the dam is placed.

8. Hole-Positioning Guides:

a) Teeth as a guide:- The teeth themselves or stone cast of teeth can be

used in marking the dam. The cusp tips of posterior teeth and incisal

edges of anterior teeth can be visualized through the dam, and centers of

teeth are marked on the dam with pen.

b) Template:- Templates are available to guide the marking of dam. These

template are approximately the same size and shape as the unstretched

dam itself.

c) Rubber dam stamp:- Provides a convenient and efficient way of marking

the dam for punching.

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9. Anchors (other than clamps):

Alternatives to clamps are of two types –

a) Employs the area beneath the interdental contacts for retention. These

include interdental wedges or wood sticks inserted below the contact

point or rubber strip passed under tension through contact point and

released to lie beneath the contact area.

b) When the tapering crown/ root surface beneath the maxillary crown

diameter, the rubber dam in this case is retained by ligatures of dental

floss tied around the neck of the tooth or elastic rings which are

stretched through the contact points and released to grip the neck of the

tooth.

guidelines for positioning the holes:

1) Punch an identification hole in upper left (patient’s left) corner of the rubber

dam for ease of location when applying the rubber dam holder.

2) When operating on incisors or mesial of canine isolate from first premolar to 1st

premolar. Metal retainer are not required for this isolation.

3) When operating on canine, it is preferable to isolate from 1st molar to opposite

lateral incisor.

4) To treat a class V lesion on canine, isolate posteriorly to include first molar to

provide access for cervical retainer placement on canine.

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5) When operating posterior teeth, isolate anteriorly to lateral incisor of opposite

side. Anterior teeth included in isolation provide better access and visibility to

operator and finger rest.

6) When operating premolar punch holes to include two teeth distally and extend

anterior up to opposite lateral incisor.

7) When operating molars, punch holes as far distally as possible and extend

anteriorly to include opposite lateral incisors.

8) Isolation of minimum of three teeth recommended except in endodotnic

therapy in which the tooth to be treated is isolated.

9) The distance between holes is equal to the distance from the center of one tooth

to the center of adjacent tooth measured at the level of gingival tissue. It is

generally ¼ inch (6.3 mm).

10)When the rubber dam is applied to the maxillary teeth the first holes are

punched of central incisors which are placed approximately 1 inch (25 mm)

from the upper border so that sufficient material to cover upper lip.

11)When the rubber dam is applied to mandibular tooth, the first hole punched is

for the post anchor tooth that receives the retainer. To determine the proper

location mentally divide the rubber dam into three vertical sections : left,

middle and right.

12)When a cervical retainer is applied to isolate a class V lesion, a heavier rubber

dam is usually recommended for better tissue retraction and the hole should be

punched slightly facially to the arch form to compensate for the extension of

the dam to the cervical area. The farther gignivally the lesion extends, the

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further the hole must be positioned from the arch form. In addition the holes

should be larger and distance between it and holes for adjacent teeth should be

slightly increased.

13)When a thinner dam is used, smaller holes must be punched to achieve an

adequate seal around the teeth because the thin dam greatly elastic.

Application Techniques:

Preoperative Procedures:

Patient’s mouth is examined carefully for calculus deposits, and sharp edges on

restoration.

All contact points in operating field are checked with dental floss.

All roughness and deposits present interdentally must be removed to allow free

passage of rubber dam and prevent tearing.

Anaesthetize the gingiva when indicated

Rinse an dry the operating field.

Before rubber dam is applied to a patient a clear decision has to be made about

teeth should be isolated. Whether a single tooth or a group of teeth is to be

brought through the rubber dam will depend on the procedure to be undertaken.

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When a clamp is to be placed, three techniques of rubber dam application are

commonly used. The clamp can be applied before, after or along with the

rubber dam sheet.

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Technique 1: Clamp placement prior to rubber dam

Step 1:- Testing and lubricating the proximal contacts:- Passing the floss

through the contacts identifies any sharp edges of restorations or enamel that

must be smooth or removed from the teeth to be isolated. Waxed dental tape

may lubricate tight contacts to facilitate dam placement.

Step 2:- Punching the holes:- It is recommended that assistant punch the holes

after assessing the arch form and tooth alignment. Holes can be marked by

using template or rubber dam stamp.

Step 3:- Lubricating the dam:- Lubrication of both the sides of rubber dam in

the area of punched holes using cotton roll or gloved fingertips. The lips and

corners are lubricated with petroleum jelly or cocoa butter.

Step 4:- Selecting the retainer:- Try the retainer on tooth to verify retainers

stability and tie the floss.

Step 5:- Testing retainer stability and retention:- If during trial placement the

retainer seem to be acceptable, remove the forcep and check for stability and

retention.

Step 6:- Positioning the dam over the retainer:- With the forefinger stretch the

anchor hole of dam over the retainer bow first and then under jaw. The

forefingers may thin out to single thickness, the septal dam for the mesial

contact of retainer tooth and attempts to it through the contact lip of the hole

first.

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Step 7: Applying the Napkin:- The operator now gather the rubber dam in left

hand and inserts the right hand through the napkin opening and grasps the

bunched dam held by operator.

Step 8:- Positioning of Napkin

Step 9:- Attaching the frame: The operator unfolds the dam and stretches over

the rubber dam frame.

Step 10:- Attaching the neck strap: (optional) Neck straps attached to the frame

and its tension is adjusted to stabilize the frame and hold the frame.

Step 11:- Passing the tooth to distal contact: If there is tooth distal to the

retainer the distal edge of post anchor hole should be passed through the

contact.

Step 12:- Applying compound (optional): If stability of retainer is questionable,

low fusing modeling compound may be applied.

Step 13:- Applying the anterior anchor (if needed): The operator passes the

dam over the anterior anchor tooth anchoring anterior portion of rubber dam.

Step 14:- Passing the septa through contacts without taper. The operator passes

the septa through as many contacts as possible without the use of dental tape by

stretching the septal dam faciogingivally and linguogingivally with the

forefingers. Pressure from a blunt hand instrument (e.g. beaver-tail burnisher)

applied in the facial embrasure gingival to the contact usually is sufficient to

obtain enough separation to permit the septum to pass through contact.

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Step 15:- Passing the septa through the contacts with tape. Use waxed dental

tape to pass the dam through the remaining contacts. Tape is preferred over

floss because its wider dimension more effectively carries the rubber septae

through the contact. The waxed variety makes passage easier and decreases the

chances for cutting holes in the septa or tearing the edges of holes.

Step 16:- Technique for using tape (optional):- Often several passes with dental

tape are required to carry a reluctant septum through a tight contact, when this

happen previously passed tape should be left in the gingival embrasure until the

entire septum has been placed successfully with passage of time.

Step 17:- Inverting the dam interproximally: Invert the dam into the gingival

sulcus to complete the seal around the tooth and prevent leakage.

Step 18:- Inverting the dam faciolingually: Complete the inversion facially and

lingually using an explorer or beaver-tail burnisher while the assistant directs a

stream of air onto the tooth. This is done by moving the explore around the

neck of the tooth facially and lingually with tip. The tooth surface or directed

slightly gingivally.

Step 19:- Using a saliva ejector

Step 20:- Confirming a properly applied rubber dam

Step 21:- Checking for access and visibility

Step 22:- Inserting the wedges

Technique 2: Applying dam and retainer simultaneously

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Winged/ clamps are used in this technique. The retainer and dam may be

placed simultaneously to reduce the risk of retainer being swallowed or

aspirated before the dam is placed.

In this method first apply the posterior retainer to verify the stable fit.

Remove the retainer and with the forceps still holding the clamps, pass the bow

through the proper hole from the underside of dam.

When using retainer with lateral wings, place the retainer in hole

punched for the anchor tooth by stretching the dam to engage these wings. The

operator conveys the retainer (with dam) into the mouth and positions it on

anchor tooth.

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Technique 3: Applying dam before the retainer

The dam may be stretched over the anchor tooth before the retainer is

placed. It is recommended for anterior teeth perhaps including first premolar.

Preferred technique when double bow or butterfly clamps are selected.

Multiple tooth isolation:

Multiple restorations and quadrant dentistry may require much larger

number of teeth to be isolated.

- Whenever possible clamps should not be placed on the tooth

which requires restoration of proximal surfaces. The clamp is

placed on the next tooth distal to it. If tooth is narrow

mesiodistally the second tooth to the distal is preferable to

provide optimum access.

- When several teeth require treatment the operating field is

extended mesially or across the arch to provide clear access to

all the teeth and maximize retention.

- The more teeth included the better the retraction of lips, cheek

and tongue and better the access.

- The minimum operating field for one tooth to be restored

proximally will therefore include teeth, one distal which will

usually be clamped, and one mesial which is often not clamped.

- As the rubber is passed through each of remaining contacts in

operating field, care must be taken to allow only one edge of

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the interdental web of rubber dam i.e. leading edge to be carried

initially into each contact area. This process is referred to as

“Knifing the rubber dam through the contacts”, accomplished

by stretching the rubber dam between the fingers to form a thin

“knife edge” aimed at contact point. Knife edge of the rubber

dam can be often “sawn” past the contact pulling it gingivally.

- The edge of rubber dam is inverted proximally first and then

faciolingually. A ligature of dental floss can be placed around

the neck of tooth to hold the rubber dam inverted.

Removal of Rubber Dam:

Before removal of rubber dam, rinse and suction away any debris

that may have collected to prevent its falling into the floor of mouth

during the removal procedures.

Step 1: Cutting the septa: Stretch the dam facially pulling the septal

rubber away from gingival tissues and tooth. Clip each septum with

blunted tip scissors, freeing the dam from the inter proximal space, but

the dam is left over the anterior and posterior anchor teeth.

Step 2:- Removing the retainer: Remove the retainer by engaging it to

the forceps.

Step 3: Removing the dam: Once the retainer is removed, release the

dam from anterior anchor tooth and remove the dam and frame

simultaneously.

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Step 4:- Wiping the lips: Wipe the lips with napkin immediately after

the removal of dam and frame.

Step 5:- Rinsing the mouth and managing the tissue

Step 6:- Extracting the dam

Rubber dam in clinical restorative procedures:

1) Endodontics: Rubber dam application in endodontics is essential to

ensure the patient’s safety during treatment. Aspiration or swallowing of

root canal instruments makes its use an integral part of endodontic

practice.

2) Soft tissue control:- Control of lips, cheek and tongue can prove difficult

with some patient generally the young patient or patients who find hard

to cooperate during restorative procedure. The use of rubber dam

enables fast and efficient treatment in such cases.

3) Cavity preparation:- Rubber dam provides a controlled pleasant

operating environment. The enhanced contrast of cavity margins with

rubber sheet, improved access and safety, moisture control recompense

for extra effort.

4) Specialized clamps / retainer:-

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a. Clamps with the extended bows i.e. the bows lies more distally

than the standard clamp. E.g. Dentsply HW pattern and Ash AD

pattern. They can be used if the preparation distal surface of

clamped tooth is necessary.

b. Modified bow clamps designed to deal with problems

encountered when clamp has to be placed on the third molar.

Standard clamp bow interfere with the ramus of mandible.

Modified bow clamps are so designed that bow lies offset to one

side i.e. palatal side and thus not interfere with ramus.

The standard clamps can be modified by heat treatment and bending the

bow distally.

Modification of rubber dam clamp increases access to distal surface of

anchor teeth.

c. Cervical retainer:- The use of cervical retainer for restoration of

class V cavity was recommended by Markley. E.g. of cervical

retainer Ferrier 212 or Dentsply C. Teeth with cervical cavities

which extend subgingivally usually requires soft tissue at the

gingival margin to be retracted. The retraction force and retention

of these clamps on the tooth is provided mainly by impression

compound which is softened and moulded around the clamp

bows and onto adjacent teeth. While the impression compound is

hardening, pressure is applied to the clamp to press it gingivally

and so reflect the soft tissue margins. As a rule the facial jaw of

the clamp should be 0.5 to 1 mm gingival to anticipated location

of gingival margin of completed tooth preparation.

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5) Fixed bridge isolation:- It is sometimes necessary to isolate one or more

abutment teeth of a fixed bridge. Indications for fixed bridge isolation

include restoration of an adjacent proximal surface and cervical

restoration of an abutment teeth.

The rubber dam is punched as usual except for providing one large hole

for each unit in the bridge. Fixed bridge isolation is accomplished after

the remaining dam is applied.

A blunted curved suture needle with dental floss attached is threaded

from the facial aspect through the hole from the anterior abutment and

bask through the same hole on lingual side. The needle direction is then

reviewed as it is passed from the lingual side through the hole for the

second bridge unit, then under the same anterior connector and through

the hole of second bridge unit on facial side. A square knot is then tied

with the two ends of floss thereby pulling the dam material smugly

around the connector and into gingival embrasure.

6) Rubber dam in Pedodontics:- The age of the patient often dictates

changes in the procedures of rubber dam application. Because young

patient have small dental arches than adult patient holes should be

punched accordingly. For primary teeth isolation is usually from most

post tooth to canine as the same side. Rubber dam sheet is smaller 5 x 5

inch (12.5 x 12.5 cm).

The unpunched rubber dam is attached to the frame, the holes are

punched, the dam with frame is applied over the anchor tooth, and

retainer is applied. The jaws of the retainers should be directed more

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gingivally because of short clinical crowns or because the anchor tooth’s

height of contour is below the crest of gingival tissue.

SS White No.27 recommended for primary and Ivory No.214

retainer for young permanent teeth.

Isolated teeth with short clinical crowns (other than anchor tooth)

may require ligation to hold the dam position. Rubber dam described as

“Rubber Rain Coat” for young children.

Errors in Application and Removal:

Certain errors in application and removal can prevent adequate

moisture control, reduce access and visibility or cause injury to the

patient.

1) Off center arch form:- A rubber dam punched off center may not

adequately shield the patient’s oral cavity, allowing the foreign matter to

escape down the patient’s throat. It can result in excess of material

superiorly that may occlude the patient’s nasal airway.

2) Inappropriate distance between the holes:- Too little distance precludes

adequate isolation because holes of rubber dam are stretched and will

not fit smugly around the necks of the teeth. Conversely too much

distance causes wrinkles between the teeth.

3) Incorrect arch form of holes:- If the punched arch form is tooth small,

the holes will be stretched open around the teeth, permitting leakage.

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4) Inappropriate retainers:-

a. If too small, resulting in occasional breakage when jaws are

overspread.

b. Unstable on anchor tooth

c. Impinge on soft tissue

d. Impede wedge placement.

5) Retainer pinched tissue: Jaws and prongs of rubber dam retainer usually

depress the tissue but should not impinge on it.

6) Incorrect location of hole for class V lesion:- If there is an incorrect

location of hole for class V lesion and hole is not punched facial to arch

form, circulation of interproximal tissue will be diminished.

7) Sharp tips on No.212 retainer:- Sharp tips on retainer No.212 is dulled to

prevent damaging the cementum.

8) Incorrect technique for cutting septa:- During removal of rubber dam an

incorrect technique for cutting the septa may result in cut tissue or a torn

septa.

Washed Field Apparatus:

This method employs inexpensive plastic tubing that is attached

to saliva ejector hose at one end and to the clamp or rubber dam itself at

the other. Childers and Marshall’s have recommended the use of clear

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vinyl tubing with inside diameter of 0.0625 inch and an outside diameter

of 0.125 inch. As connector for saliva ejector hose recommended clear

vinyl tubing with an inside diameter of 0.125 inch and outside diameter

of 0.025 inch. The end of smaller diameter tube is carried under the

rubber dam frame and tucked under the bow o a wing of rubber dam

clamp in back of dam tubing may be attached to rubber dam by

cyanoacrylate adhesive. The washed field apparatus is used for

evacuation of fluids from dam when no assistant is available.

Alternative isolation aids

Retraction cord when properly applied can be used for isolation and

retraction in the direct procedures of treatment of cervical lesions in facial

veneering as well as in indirect veneers.

The gingival retraction when moistened with a non caustic styptic may

be placed in gingival sulcus to control sulailar seepage and or hemorrhage.

Most brands are available with and without the voso constrictor

epinephrine which acts to control sulculae fluids.

A properly applied retraction cord, will improve access and visibility

and help prevent abrasion of gingival tissue during cavity preparation.

Antisalivary drugs

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The use of drugs in restorative dentistry to control salivation is rarely

indicated and generally limited to atropine.

Is with any drug the operator should be familiar with its indications

contra indications and side effects. It is important to remember that atropine is

contra indicated for nursing mothers and for patients with glaucoma.

Some Anti histaminics like Hi receptor antagonists also cause dryness of

mouth due to anti cholinergic action but they inhibit the action of local

anesthesia so are contra indicated.

Although several methods and devices are available to create a dry

working field. The rubber dam is one of the most ideal the working field that is

produced is in principle.

In medicine, surgical procedures are done with controller operating

field’s surrounded by aseptic environment. An attempt should be made in

restorative dentistry to work only on clean teeth and on a patient who is under

control. Control should mean not only the elimination of moisture but the

elimination of humidity as well utilizing all the above mentioned measures.

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Contents

1. Introduction

2. Methods of Isolation

3. Rubber Dam

4. Drugs

5. Conclusion

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