Copyright 2003, Elsevier Science (USA). All rights reserved. Treatment of pulpitis with biological, vital amputational and extirpation methods. Testimony,

Copyright 2003, Elsevier Science (USA). All rights reserved.

Treatment of pulpitis with Treatment of pulpitis with biologicalbiological, , vital amputational vital amputational

and extirpation methodsand extirpation methods. . Testimony, sequence and Testimony, sequence and

features of the stages. features of the stages. Efficiency of methods, Efficiency of methods,

complication and methods of complication and methods of its prevention.its prevention.

Treatment of pulpitis with Treatment of pulpitis with biologicalbiological, , vital amputational vital amputational

and extirpation methodsand extirpation methods. . Testimony, sequence and Testimony, sequence and

features of the stages. features of the stages. Efficiency of methods, Efficiency of methods,

complication and methods of complication and methods of its prevention.its prevention.

Therapeutic dentistry departmentTherapeutic dentistry department

Lecturer: as. Yavors’ka-Skrabut I.M.Lecturer: as. Yavors’ka-Skrabut I.M.


Endodontics is the specialty of dentistry that manages the prevention, diagnosis, and treatment of the dental pulp and the periradicular tissues that surround the root of the tooth.

IntroductionIntroduction


• Physical irritation • Most generally brought on by

extensive decay.• Trauma

– Blow to a tooth or the jaw.

Causes of Pulpal Nerve Damage

Causes of Pulpal Nerve Damage


• Pain when biting down.• Pain when chewing. • Sensitivity with hot or cold

beverages. • Facial swelling.

Signs and Symptoms of Pulpal Nerve Damage

Signs and Symptoms of Pulpal Nerve Damage


• Subjective examination– Chief complaint – Character and duration of pain – Painful stimuli – Sensitivity to biting and pressure

Endodontic Diagnosis Endodontic Diagnosis


• Objective examination– Extent of decay – Periodontal conditions surrounding

the tooth in question – Presence of an extensive restoration – Tooth mobility – Swelling or discoloration – Pulp exposure

Endodontic DiagnosisEndodontic Diagnosis


• Percussion tests – Used to determine whether the

inflammatory process has extended into the periapical tissues.

– Completed by the dentist tapping on the incisal or occlusal surface of the tooth in question with the end of the mouth mirror handle held parallel to the long axis of the tooth.

Diagnostic Testing Diagnostic Testing


• Palpation tests– Used to determine whether the

inflammatory process has extended into the periapical tissues.

– The dentist applies firm pressure to the mucosa above the apex of the root.

Diagnostic Testing cont’d Diagnostic Testing cont’d


• Thermal sensitivity• Necrotic pulp will not respond to cold or

hot.• Cold test

• Ice, dry ice, or ethyl chloride used to determine the response of a tooth to cold.

• Heat test• Piece of gutta-percha or instrument

handle heated and applied to the facial surface of the tooth.



• Electric pulp testing• Delivers a small electrical stimulus to the pulp.

• Factors that may influence readings:• Teeth with extensive restorations.• Teeth with more than one canal. • Failing pulp can produce a variety of responses. • Control teeth may not respond as anticipated. • Moisture on the tooth during testing.• Batteries in the tester may be weak.



Fig. 54-4 Placement of a pulp tester.


• Initial radiograph – Diagnosis.

• Working length film – Used to determine the length of the canal.

• Final instrumentation film – Taken with the final size files in all canals.

• Root canal completion film – Taken after the tooth as been temporized.

• Recall films – Taken at evaluations.

Radiographs in Endodontics

Radiographs in Endodontics


• Show 4-5 mm beyond the apex of the tooth and the surrounding bone or pathologic condition.

• Present an accurate image of the tooth without elongation or fore-shortening.

• Exhibit good contrast so all pertinent structures are readily identifiable.

Requirements of Endodontic Films

Requirements of Endodontic Films


Fig. 54-5 Quality radiograph in endodontics.


• Normal pulp– There are no subjective symptoms or

objective signs. The tooth responds normally to sensory stimuli, and a healthy layer of dentin surrounds the pulp.

Diagnostic Conclusions Diagnostic Conclusions


• Pulpitis – The pulp tissues have become inflamed.

• Reversible pulpitis– The pulp is irritated, and the patient is

experiencing pain to thermal stimuli. • Irreversible pulpitis

– The tooth will display symptoms of lingering pain.

Diagnostic ConclusionsDiagnostic Conclusions


• Periradicular abscess– An inflammatory reaction to pulpal

infection that can be chronic or have rapid onset with pain, tenderness of the tooth to pressure, pus formation, and swelling of the tissues.

Diagnostic Conclusions Diagnostic Conclusions


• Periodontal abscess – An inflammatory reaction frequently

caused by bacteria entrapped in the periodontal sulcus. A patient will experience rapid onset, pain, tenderness of the tooth to pressure, pus formation, and swelling.



• Periradicular cyst– A cyst that develops at or near the

root of a necrotic tooth. These types of cysts develop as an inflammatory response to pulpal infection and necrosis of the pulp.



• Pulp fibrosis– The decrease of living cells within the

pulp causing fibrous tissue to take over the pulpal canal.



• Necrotic tooth– Also referred to as nonvital. Used to

describe a tooth that does not respond to sensory stimulus.



• Pulp capping– A covering of calcium hydroxide is

placed over an exposed or nearly exposed pulp to encourage the formation of irritated dentin at the site of injury.

• Indirect pulp cap is indicated when a thin partition of dentin is still intact.

• Direct pulp cap is indicated when the pulp has been slightly exposed.

Endodontic Procedures Endodontic Procedures


Fig. 54-11 Spreader and plugger.


• Pulpotomy – Involves the removal of the coronal

portion of an exposed vital pulp.– Completed to preserve the vitality of

the remaining portion of the pulp within the root of the tooth.

– This procedure is commonly indicated for vital primary teeth, teeth with deep carious lesions, and emergency situations.

Endodontic ProceduresEndodontic Procedures


Fig. 54-13 Example of a pulpotomy.


• Pulpectomy – Also referred to as root canal

therapy; procedure involves the complete removal of the dental pulp.

Endodontic ProceduresEndodontic Procedures


Fig. 54-14 A diagram of a pulpectomy.


• Endodontic explorer • Endodontic spoon excavator • Broaches• Endodontic files

– K-type– Hedstrom

Instruments and Accessories for Endodontic Procedures



Table 54‑1 Colors and Sizes of Endodontic Files


• Rubber stops • Paper points • Spreaders • Pluggers • Glick No. 1• Millimeter ruler




• Rotary instruments – Gates-Glidden bur – Pesso reamer – Lentulo spiral




• Irrigation solution – Sodium hypochlorite – Hydrogen peroxide – Parachlorophenol (PCP)

Medicaments and Dental Materials in Endodontics Medicaments and Dental Materials in Endodontics


• Gutta-percha points• Formocresol • Root canal sealer

Medicaments and Dental Materials in EndodonticsMedicaments and Dental Materials in Endodontics


• Anesthesia and pain control

• Isolation and disinfection of the site

• Access preparation

• Debridement and shaping the canal

• Obturation

Overview of Root Canal Therapy

Overview of Root Canal Therapy


• Indications for surgical intervention– Endodontic failure caused by

persistent infection, severely curved roots, perforation of the canal, fractured roots, extensive root resorption, pulp stones, or accessory canals that cannot be treated.

– Exploratory surgery to determine why healing has not occurred.

– Biopsy

Surgical Endodontics Surgical Endodontics


• To surgically remove the apical portion of the root with the use of a high‑speed handpiece and bur.

• To evaluate:– Inadequate sealing of the canal. – Accessory canals. – Fractures of the root. – Pathological tissue around the root

apex.

Apicoectomy and Apical Curettage

Apicoectomy and Apical Curettage


• Completed when an apical seal is not adequate. A small class I preparation is made at the apex and sealed with filling materials such as gutta-percha, amalgam, or composite.

Retrograde Restoration Retrograde Restoration


• Root amputation– A surgery performed to remove one or

more roots of a multirooted tooth without removing the crown.

• Hemisection– A procedure in which the root and the

crown are cut lengthwise and removed.

Root Amputation and Hemisection

Root Amputation and Hemisection


Treatment Treatment of of

Reversible Reversible PulpitisPulpitis


• Remove irritant if present (caries; Remove irritant if present (caries; fracture; exposed dentinal tubules).fracture; exposed dentinal tubules).

– If no pulp exposure: CaOH, restore, If no pulp exposure: CaOH, restore, monitormonitor

– If pulp exposure:If pulp exposure:• Carious: initiate RCTCarious: initiate RCT

• Mechanical: >1 mm: initiate RCTMechanical: >1 mm: initiate RCT

<1 mm crown planned: <1 mm crown planned: initiate RCTinitiate RCT

<1 mm: direct cap or RCT<1 mm: direct cap or RCT

• If recent operative or trauma – postpone If recent operative or trauma – postpone additional treatment and monitor.additional treatment and monitor.


• Pulpal inflamation and degeneration Pulpal inflamation and degeneration not not expected to improve.expected to improve.

• A physiologically older pulp has less ability to A physiologically older pulp has less ability to recover due to decrease in vascularity and recover due to decrease in vascularity and

reparative cells.reparative cells.

• As inflammation spreads apically, cellular As inflammation spreads apically, cellular organization begins to break down.organization begins to break down.

• Localized pressure slows venous return, Localized pressure slows venous return, resulting in buildup of toxins and lower pH resulting in buildup of toxins and lower pH

that causes widespread cellular destruction.that causes widespread cellular destruction.


EndodontiEndodontic c

MaterialsMaterials



Functions of Functions of irrigantsirrigants

• Irrigants are used to clean the root Irrigants are used to clean the root canal and are used in association with canal and are used in association with the shaping instruments.the shaping instruments.

• Functions of irrigants include:Functions of irrigants include:1.1. Lubrication of instruments used to Lubrication of instruments used to

shape the canal.shape the canal.2.2. Flushing out of gross debris.Flushing out of gross debris.3.3. Dissolution of organic and inorganic Dissolution of organic and inorganic

tissue.tissue.4.4. Antimicrobial effect.Antimicrobial effect.


IrrigantsIrrigants

• Ideal properties:Ideal properties:– LubricantLubricant– AntimicrobialAntimicrobial– Dissolve organic debrisDissolve organic debris– FlushingFlushing– BiocompatibleBiocompatible– CheapCheap


Classification of irrigantsClassification of irrigants• Chemically inactive irrigantsChemically inactive irrigants

– WaterWater– SalineSaline– Local anaesthetic solutionLocal anaesthetic solution

• Chemically active irrigantsChemically active irrigants– Sodium hypochlorite (NaOCl).Sodium hypochlorite (NaOCl).– Oxidizing agents as Hydrogen peroxide Oxidizing agents as Hydrogen peroxide

(H(H22OO22))

– Chelating agents as EDTA.Chelating agents as EDTA.


IrrigantsIrrigants• UseUse

– Adequate volume requiredAdequate volume required– Stays within the confines of Stays within the confines of root canalroot canal– Never deliver with excessive Never deliver with excessive forceforce

• Apical extrusion results Apical extrusion results in painin pain and possibleand possible swelling.swelling.

– Use luer-lok 27 gauge endodontic needleUse luer-lok 27 gauge endodontic needle– Efficiency enhanced with ultrasonic, sonic and Efficiency enhanced with ultrasonic, sonic and

mechanical instrumentsmechanical instruments


Sodium hypochloriteSodium hypochlorite• 0.5-5.25 %0.5-5.25 %• AntibacterialAntibacterial• Dissolve organic matterDissolve organic matter• Corrosive/causticCorrosive/caustic• Low toxicityLow toxicity• Apical reactionApical reaction• Rubber damRubber dam


Hydrogen peroxideHydrogen peroxide

•3% +/- NaOCl3% +/- NaOCl•Production of O2 eliminate Production of O2 eliminate

anaerobesanaerobes•Bubbles may prevent adequate Bubbles may prevent adequate

contact of irrigant with debriscontact of irrigant with debris•Limited shelf lifeLimited shelf life


ChlorhexidineChlorhexidine• Hibisrcub(Hibisrcub(HIBISCRUB is an antimicrobial

preparation for pre-operative surgical hand disinfection, antiseptic handwashing

• Usually used in 0.2% concentrationUsually used in 0.2% concentration• Antibacterial, Substantivity. Antibacterial, Substantivity.

• FlushingFlushing• LubricantLubricant

• Does not dissolve organic debrisDoes not dissolve organic debris


Chelating agentChelating agent

• Ethylene Diamine Tetracetic Acid Ethylene Diamine Tetracetic Acid “EDTA” (File-eze, RC Prep)“EDTA” (File-eze, RC Prep)

• Remove smear layer allowing Remove smear layer allowing

cleaning of tubulescleaning of tubules• Soften dentineSoften dentine

• Not antibacterialNot antibacterial• File-eze is water soluble unlike RC Prep File-eze is water soluble unlike RC Prep

which contains carbowax and is difficult which contains carbowax and is difficult to removeto remove


IrrigantsIrrigants

• Sterile waterSterile water• Local anaestheticLocal anaesthetic

• Saline (0.9%)Saline (0.9%)

They only provide lubrication and They only provide lubrication and gross debris removal functions.gross debris removal functions.


Intracanal medicamanetsIntracanal medicamanets• If root canal treatment can’t be finished in a single visit, root If root canal treatment can’t be finished in a single visit, root

canals are dressed with medicaments.canals are dressed with medicaments.• Functions of intracanal medicaments:Functions of intracanal medicaments:

– Primary function: antimicrobial activityPrimary function: antimicrobial activity• Antisepsis(Antisepsis(is the destruction or inhibition of (slowing the

growth of) microorganisms )• Disinfection(Disinfection(Cleaning an article of some or all of the

pathogenic organisms which may cause infection )– Secondary functionsSecondary functions

• Hard-tissue formationHard-tissue formation• Pain controlPain control

• Exudation controlExudation control• Resorption controlResorption control


Intracanal medicamentIntracanal medicament• Ideal propertiesIdeal properties

– AntibacterialAntibacterial– Penetrates dentinal tubulesPenetrates dentinal tubules– Control exudation or bleedingControl exudation or bleeding– Biocompatibile.Biocompatibile.– Eliminates painEliminates pain– Induce calcific barrierInduce calcific barrier– No effect on temporaryNo effect on temporary– Radio-opaqueRadio-opaque– Does not stain toothDoes not stain tooth


Calcium hydroxideCalcium hydroxide

• Hypocal(Hypocal(contains calcium hydroxide and barium sulfate)

• Ca(OH)2, 34-50% Ba SO4,5-15% Ca(OH)2, 34-50% Ba SO4,5-15% Methylcellulose.Methylcellulose.

• Antibacterial (pH>12)Antibacterial (pH>12)• Denatures proteinDenatures protein• Synergestic with NaOCLSynergestic with NaOCL• Cytotoxic-local necrosis, calcific barrierCytotoxic-local necrosis, calcific barrier• CheapCheap• Dries weeping canalsDries weeping canals


AntibioticsAntibiotics

• Combination of drugs Combination of drugs required to be effectiverequired to be effective

• Resistant strains becoming Resistant strains becoming more difficult to treatmore difficult to treat

• AllergiesAllergies


SteroidsSteroids

• Triamicinolone, prednisoloneTriamicinolone, prednisolone• Pain relief but no evidence of more effective Pain relief but no evidence of more effective

than Ca(OH)2than Ca(OH)2• ?use in root resorption by inhibiting ?use in root resorption by inhibiting

odontoclastsodontoclasts• ?depresses the host inflammatory response?depresses the host inflammatory response

• Not antibacterial but can be mixed with Not antibacterial but can be mixed with Ca(OH)2Ca(OH)2

• Ledermix= triamicinolone+ tetracyclineLedermix= triamicinolone+ tetracycline


Phenol based agents, Phenol based agents,

Aldehydes and HalidyesAldehydes and Halidyes • Phenol, parachlorophenol(PCP), Phenol, parachlorophenol(PCP),

camphorated mono PCP, cresol, camphorated mono PCP, cresol, creosote, formacresol and creosote, formacresol and

chlorine.chlorine.• Antibacterial agents.Antibacterial agents.• Highly toxic agents.Highly toxic agents.

• Possible mutagenic and Possible mutagenic and carcinogenic effect. carcinogenic effect.


Obturating materialsObturating materials• Ideal properties of root canal filling materials:Ideal properties of root canal filling materials:

– AntimicrobialAntimicrobial– Biocompatible.Biocompatible.– Good flowGood flow– Adhesive in natureAdhesive in nature– Dimensionally stableDimensionally stable– Not affected by moistureNot affected by moisture– Radio-opaqueRadio-opaque– Good handlingGood handling– Easily removed, post prep or retreatEasily removed, post prep or retreat– Does not stain dentineDoes not stain dentine– CheapCheap


Gutta PerchaGutta Percha

Gutta percha “ Isoprene” (CGutta percha “ Isoprene” (C55HH88) is one of the ) is one of the oldest and most common root filling oldest and most common root filling material in use today. material in use today.

A natural latex produced from a genus of A natural latex produced from a genus of tropical treestropical trees

• Polymers of isoprene:Polymers of isoprene:– Cis-natural rubberCis-natural rubber– Trans-gutta percha.Trans-gutta percha.


Gutta percha points used in clinic Gutta percha points used in clinic consists of:consists of:

• Gutta percha 20%Gutta percha 20%• Zinc oxide 60-75%Zinc oxide 60-75%• Metal sulphides, waxes, resin, opacifiersMetal sulphides, waxes, resin, opacifiers

Gutta percha is available in 2 phases; Alpha and Gutta percha is available in 2 phases; Alpha and Beta.Beta.


• Gutta percha taken from trees is Gutta percha taken from trees is in in Alpha phase.Alpha phase.

• Gutta percha in points used in Gutta percha in points used in the clinic is in the clinic is in Beta phase.Beta phase.

• Both phases differ in Melting Both phases differ in Melting temperature, volumetric changes temperature, volumetric changes and flow characteristics when and flow characteristics when molten.molten.



Gutta perchaGutta percha

Advantages of gutta percha:Advantages of gutta percha:• BiocompatibleBiocompatible• Dimensionally stableDimensionally stable• Compactable Compactable • Easily removedEasily removed• Cheap Cheap Disadvantages of gutta percha:Disadvantages of gutta percha:• Does not adhere to dentine Does not adhere to dentine • Lacks rigidityLacks rigidity


Metal pointsMetal points


SealersSealers

• Sealers are used in association with Gutta Sealers are used in association with Gutta percha. percha.

• Functions of sealerFunctions of sealer– Cementing (luting, binding) the core material Cementing (luting, binding) the core material

(gutta percha) into the canal.(gutta percha) into the canal.– Filling the discrepancies between the canal Filling the discrepancies between the canal

walls and core materialwalls and core material– Acting as a lubricant to enhance the positioning Acting as a lubricant to enhance the positioning

of the core filling materialof the core filling material– Acting as a bactericidal agentActing as a bactericidal agent


Root canal sealersRoot canal sealers

• Most sealers are toxic when freshly mixedMost sealers are toxic when freshly mixed• Toxicity substantially reduced when setToxicity substantially reduced when set• Most sealers are absorbable to some Most sealers are absorbable to some

extent when exposed to tissue fluidextent when exposed to tissue fluid• Ideally sealer should flow backwards out Ideally sealer should flow backwards out

of the canalof the canal– However, no evidence that apical However, no evidence that apical

extrusion reduces success rate extrusion reduces success rate providing preparation and obturation providing preparation and obturation are meticulousare meticulous


Zinc-oxide eugenolZinc-oxide eugenol

• Grossmans, TublisealGrossmans, Tubliseal• AntibacterialAntibacterial• Radio-opaqueRadio-opaque• Slightly toxic when Slightly toxic when

freshly mixed.freshly mixed.• Good flow and Good flow and

working timeworking time• Does not adhereDoes not adhere• solublesoluble


Calcium hydroxide Calcium hydroxide based sealersbased sealers

• Sealapex, ApexitSealapex, Apexit• Radio-opaqueRadio-opaque• SolubleSoluble• BiocompatibleBiocompatible• Preserve vitality of pulp stump Preserve vitality of pulp stump

and promote healingand promote healing• Does not adhereDoes not adhere


Resin based sealersResin based sealers

• AH26, AH Plus, Endorez, AH26, AH Plus, Endorez, Epiphany, RealSeal.Epiphany, RealSeal.

• AdhesiveAdhesive• AntibacterialAntibacterial• Toxic when freshly mixedToxic when freshly mixed• Show setting shrinkage when setShow setting shrinkage when set


Glass-ionomer based sealersGlass-ionomer based sealers

• Ketac Endo and ActiV GP.Ketac Endo and ActiV GP.• Mildly antibacterialMildly antibacterial• Adheres to dentineAdheres to dentine• Slightly solubleSlightly soluble• Unset GIC is cytotoxic but when Unset GIC is cytotoxic but when

set this reduces with timeset this reduces with time• Very difficult to be removedVery difficult to be removed


Silicone based sealersSilicone based sealers

• Roekoseal sealer.Roekoseal sealer.• Slightly expands when set. Slightly expands when set. • Addition type silicone.Addition type silicone.• GuttaFlow is Roekoseal sealer with GuttaFlow is Roekoseal sealer with

added gutta percha particles.added gutta percha particles.• Does not adhere to root canal.Does not adhere to root canal.


New root canal filling New root canal filling materialsmaterials

• Resilon: Resilon: resin-based cones. Similar in resin-based cones. Similar in appearance and handling to gutta percha appearance and handling to gutta percha cones. Used with any resin-based sealer.cones. Used with any resin-based sealer.

• Endorez cones: Endorez cones: resin-coated gutta resin-coated gutta percha. Used with endorez sealer or any percha. Used with endorez sealer or any other resin-based sealer.other resin-based sealer.

• ActiV GP: ActiV GP: glass ionomer coated gutta glass ionomer coated gutta percha. Used with glass ionomer based percha. Used with glass ionomer based sealers.sealers.


Retrograde root filling Retrograde root filling materialsmaterials

• Ideal propertiesIdeal properties– Seals apexSeals apex– BiocompatibleBiocompatible– Ease of handlingEase of handling– Moisture and blood tolerantMoisture and blood tolerant– Low solubilityLow solubility– Radio-opaqueRadio-opaque– Good tissue responseGood tissue response– Bonds to dentineBonds to dentine


AmalgamAmalgam

•CorrosionCorrosion•Apical inflammationApical inflammation•Poor sealing abilityPoor sealing ability•Mercury toxicityMercury toxicity


IRMIRM

• Modified zinc oxide-eugenolModified zinc oxide-eugenol• Seals better than amalgamSeals better than amalgam• Need high powder to liquid Need high powder to liquid

ratio to decrease toxicity ratio to decrease toxicity and solubilityand solubility

• Short working timeShort working time


Super EBASuper EBA

• Modified zinc oxide-eugenolModified zinc oxide-eugenol• High compressive and tensile High compressive and tensile

strengthstrength• Neutral pHNeutral pH• Low solubiltyLow solubilty• Not affected by bloodNot affected by blood• Good tissue responseGood tissue response


CompositeComposite

•Problems with moisture Problems with moisture controlcontrol

•Some good results in Some good results in sealing ability but sealing ability but further work requiredfurther work required


Glass Ionomer CementsGlass Ionomer Cements

• Bonds to tooth substanceBonds to tooth substance• Biocompatibilty (Toxicity reduces Biocompatibilty (Toxicity reduces

when set)when set)• Some antibacterial propertiesSome antibacterial properties• Seal superior to amalgamSeal superior to amalgam


New materialsNew materials

• Diaket (Tricalcium phosphate paste)Diaket (Tricalcium phosphate paste)– Polyvinyl resinPolyvinyl resin– Good tissue responseGood tissue response– ?cementum forming?cementum forming

• Mineral Trioxide aggregates (MTA)Mineral Trioxide aggregates (MTA)– Seals better than amalgam or super EPASeals better than amalgam or super EPA– Not adversly affected by bloodNot adversly affected by blood– Marginal adaptation better than amalgam, IRM or Marginal adaptation better than amalgam, IRM or

super EBAsuper EBA– ?cytotoxicity?cytotoxicity

• LaserLaser• HydroxyapatiteHydroxyapatite


MTAMTA

•Mineral trioxide aggregate:Mineral trioxide aggregate:•Pulp cappingPulp capping•Nonsurgical apical closureNonsurgical apical closure•Perforation repairPerforation repair•Surgical root end fillingSurgical root end filling


ACCESS CAVITIESACCESS CAVITIES


• Despite advances there is always a chance of error in endodontic therapy, and diligence in the involved procedures is necessary.


• it is important that the access preparation be precise

• Entering a tooth without an adequate radiograph is a “fool’s errand.”


• Preoperative radiographs are essential because they tell us where pulp chambers are located in relationship to coronal surfaces, and at what angles canals enter pulp chambers


• Gaining access to root canals, wherein Gaining access to root canals, wherein the root canal instruments can be slipped the root canal instruments can be slipped easily into the canals to reach the apical easily into the canals to reach the apical portion, is the most important starting portion, is the most important starting point of the root canal treatment. Before point of the root canal treatment. Before you lift that hand piece to start access you lift that hand piece to start access cavity preparation, stop and think about cavity preparation, stop and think about the following three points:the following three points:


• Have you refreshed the knowledge of the Have you refreshed the knowledge of the morphology and anatomy of the tooth you are morphology and anatomy of the tooth you are going to treat?going to treat?

• Have you taken a good look at the tooth in the Have you taken a good look at the tooth in the oral cavity? Its shape, size, tilt and oral cavity? Its shape, size, tilt and morphology need careful consideration.morphology need careful consideration.

• Have you spent sufficient time studying the Have you spent sufficient time studying the radiograph?radiograph?


• When the access preparation is cut too small, it is often impossible to find all the canals in the tooth.

• Even if all the canals are located, it sets the stage for negotiation difficulties, file breakage, and unnecessary frustration during obturation procedures.



• Conversely, access cavities that are cut too big are a betrayal of the clinician’s first admonishment to do no harm, increasing the short-term possibility of perforation and the long-term probability of tooth and root fracture.


CHOOSE SAFE, EFFECTIVE BURS

• choosing the wrong bur can presage a poor access result

• burs that are too large will inevitably increase the size of the final cavity preparation as well as significantly increase the potential for tooth perforation


• #2 round is ideal for anterior and premolar access

• a #4 is optimal for molar access


• As soon as the author drops into the chamber, the round bur has accomplished its purpose and is replaced with a tapered diamond bur.


• In anterior and premolar teeth, the convenience form is afforded by extending the preparation from buccal to lingual; the conservation form is accomplished by preserving tooth structure in the mesial to distal dimension


Anterior - TriangularAnterior - Triangular


Canines - ovoidCanines - ovoid


Premolar - RoundPremolar - Round


• In posterior teeth, the line-angle extensions are cut to the working cusps and stop 1 mm to 2 mm short of the idling cusps.


• In maxillary premolars and molars, the line angle extensions are taken to the palatal cusps (working) and are short of the buccal cusps (idling)


Molar - RhomboidMolar - Rhomboid


• Conversely, in mandibular premolars and molars the line angle extensions are taken to the buccal and are short of the lingual cusps



Straight-line accessStraight-line access

• Success in modern endodontic Success in modern endodontic treatment may be dependent treatment may be dependent upon a well-designed access upon a well-designed access cavity to permit straight-line cavity to permit straight-line access to all the main root canals access to all the main root canals




Flexural stress will be increased Flexural stress will be increased if the instrument must if the instrument must

negotiate past an overhang; negotiate past an overhang; arrow A indicates overhang arrow A indicates overhang

preventing continuous straight preventing continuous straight line access; arrow B indicates line access; arrow B indicates point of greatest curvature on point of greatest curvature on

outside wall of canal.outside wall of canal.


Showing a canal opened to the Showing a canal opened to the apex to a No. 20 reamer or file; apex to a No. 20 reamer or file;

arrow indicates the thickest, arrow indicates the thickest, most engaged part of NiTi, most most engaged part of NiTi, most

prone to fractureprone to fracture

Documents

Copyright 2003, Elsevier Science (USA). All rights reserved. Treatment of pulpitis with biological, vital amputational and extirpation methods. Testimony,