Access OpeningAccess Opening

ObjectiveObjectivess

•Achieve maximum visibility of the canal

•Determine precise root canal location

•Allow for proper cleaning & shapingof the canal

•Remove causes of bacterial infection

EndodonticEndodontic CavityCavity PreparationPreparation

Coronal cavity prep

“Access Opening”

RadicularCavity Prep

“Root Canal Preparation”

PrinciplesPrinciples of Access Openingof Access Opening

Removal of carious dentine & defective restorationsOutline formConvenience formToilet of the cavity

RemovalRemoval ofof remainingremaining cariouscarious dentindentine & e & defectivedefective restorationsrestorations

Point to start openingaccessEliminate thediscolored toothstructure

RemovalRemoval ofof remainingremaining cariouscarious dentindentine & e & defectivedefective restorationsrestorations

Eliminate as manymicro-organisms aspossibleEliminate thepossibility of salivaleaking into theprepared cavity

Failure to remove caries or faulty Failure to remove caries or faulty restorationsrestorations

Reasons to remove restorationsReasons to remove restorationsEvidence of leakageEvidence of leakageCaries beneath restorationsCaries beneath restorationsFracture uncovered during access Fracture uncovered during access preparationpreparationTxTx--planned restoration replacementplanned restoration replacementConvenience to workConvenience to work

OutlineOutline formform

Evolves from internalanatomy- Size of pulp chamber- Shape of pulp chamber

ShapeShape ofof AccessAccess OOpeningpening

MaxMax insicorinsicorMaxMax molarmolarMandMand molarmolar

ShapeShape ofof AccessAccess OpeningOpening

MandMand incisorincisorMaxMax && mandmand caninecanineMaxMax && mandmand premolarpremolar

OutlineOutline formform

Evolves from internal anatomy- Age of tooth- Number, position & curvature ofcanals

ConvenienceConvenience formformUnobstructed access to the canalorificeDirect access to the apicalforamen

ConvenienceConvenience formform

Expansion to accommodatefilling techniquesComplete authority overthe instruments

ledge

Inadequate convenience form Inadequate convenience form leadleadss toto::

1.ledging

2.instrument breakage

3.incorrect shape of complete canal

4.improper debridement

ToiletToilet ofof cavitycavity

Remove aRemove allll cariecaries & s & debridebrissfromfrom chamberchamber beforebeforeradicularradicular prepprep isis begunbegunEndoEndo spoonspoon excavatorexcavator isis idealidealforfor debrisdebris removalremovalNaOCNaOCll isis an an excellentexcellentirrigationirrigation

Irrigating syringeIrrigating syringe

Access Access ที่ดีมีลักษณะที่ดีมีลักษณะ

1.No caries or defected restoration

2.No roof of pulp chamber

3.Straight line access

Access Access ที่ดีมีลักษณะที่ดีมีลักษณะ

4.ผนังเรียบตอเปนเสน

เดียวกับผนังคลองรากฟน

5.มลีกัษณะเปนรูปกรวย

ผายออกเลก็นอย

6.ไมกรอเนื้อฟนมาก

เกินไป

Front surface Front surface moumouthth mirrormirror

การเตรียมฟนกอนการเปดชองทางเขาการเตรียมฟนกอนการเปดชองทางเขา

•Temporary wall: Am, CR, GI, IRM

•Orthodontic band

•Gingivectomy

•Crown lengthening

ProcedureProceduress

Step 1 Radiograph

Step 2 Rubber dam application

Step 3 Pencil Access

Step 4 Cut through Center

Step 5 Step 5 EstablishEstablish outlineoutline formform(round diamond or carbide (round diamond or carbide bur with high speed bur with high speed handpiecehandpiece))

BursBurs

Friction Friction gripgrip::

taper fissure taper fissure 010, 012010, 012

Step 6 Remove Step 6 Remove roof of pulp roof of pulp chamber chamber ((endoendolength round bur length round bur with low speed with low speed handpiecehandpiece))

Explorer Explorer NNoo.. 55

Check roof of pulp chamber:Check roof of pulp chamber:

Step 7 Remove Li shoulder, dentineshelf

(GG, safety tip diamond)

BursBurs

SafeSafe--endedended bursburs

BursBurs

RoundRound:: normanormal l && extraextra longlong010, 014, 018010, 014, 018

••GateGatess--gliddenglidden drillsdrills

Step 8 Locate canalorifice (endo explorer):reparative dentine is softer & lighter than normal dentine

Locate canal orifices:Locate canal orifices:

EndodonticEndodontic explorerexplorer

TUG BACK in the area of canal orifice

Step 9 Check straightline access (endoexplorer or #10 file)

Irrigate often

ShapeShape ofof AccessAccess OOpeningpening

MaxMax insicorinsicorMaxMax molarmolarMandMand molarmolar

ShapeShape ofof AccessAccess OpeningOpening

MandMand incisorincisorMaxMax && mandmand caninecanineMaxMax && mandmand premolarpremolar

Maxillary anterior teethMaxillary anterior teeth

Maxillary posterior teethMaxillary posterior teeth

MandibularMandibular teethteeth

Access Access อยูอยู

กึ่งกลางกึ่งกลาง CEJCEJ

Error in Access PreparationError in Access Preparation

UnderextendedUnderextended preparationpreparationOverextended preparationOverextended preparationGougingGougingPerforationPerforationDisoriented Disoriented ((เปดทางเขาไมตรงตําแหนงเปดทางเขาไมตรงตําแหนง))

Failure to remove caries or Failure to remove caries or faulty restorationsfaulty restorations

UnderextendedUnderextended prepprep

Missed canalsMissed canalsTooth Tooth discolorationdiscoloration

UnderextendedUnderextended prepprep

Perforation or Perforation or ledge caused by ledge caused by failure to complete failure to complete convenience formconvenience formTotal loss of Total loss of instrument controlinstrument control

Overextended preparationOverextended preparation

Weakening coronal Weakening coronal tooth structure: tooth structure: Coronal fractureCoronal fracture

GougingGouging

Accumulate debrisAccumulate debrisInconvenient to Inconvenient to instrumentationinstrumentation

PerforationPerforation

Coronal to the pulp Coronal to the pulp chamberchamber

PerforationPerforation

Floor of the pulp Floor of the pulp chamberchamber

DisorientedDisorientedMisinterpretation of Misinterpretation of angulationangulationFaulty cavity has been preparing Faulty cavity has been preparing in full crownin full crown

--Missed canal

-Perforation

การเปดทางเขาคลองรากฟนไมตรงตาํแหนงการเปดทางเขาคลองรากฟนไมตรงตาํแหนง