012. access cavity preparation

EndodonticsEndodontics: :

Access Cavity Access Cavity PreparationPreparation

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Access Cavity PreparationAccess Cavity PreparationMAJOR OBJECTIVESMAJOR OBJECTIVES

11- - Straight-Line AccessStraight-Line Access

22- - Conservation of Tooth StructureConservation of Tooth Structure

33- - Unroofing of Chamber and Exposure Unroofing of Chamber and Exposure of Pulp Hornsof Pulp Horns

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Endodontic Preparation of Endodontic Preparation of Maxil lary and mandibular Maxil lary and mandibular

Anterior TeethAnterior Teeth

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55

66

77

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Maxil lary Central Incisor

Central incisor are large and on an average of 23 mm.

It has a single canal and a single apical foramen.

The pulp in young patients normally has 3 pulp horns.

The pulp chambers is noticeably wider in the faciolingual direction than in the mesiodistal.

All upper anterior teeth have one root and one canal.

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Maxil lary Lateral Incisor

It is shorter than central incisor.

Average length of 21- 22 mm.

It has a single canal and a single apical foramen.

In young patients have two only pulp horn and is wider in labiopalatal dimension.

The canal is tapered and the apex is often curved generally in distal direction.

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Maxil lary CanineIt is the longest tooth (26.5 mm)Seldom has more than one canal

The pulp chamber is quite narrow M- D, and there is one pulp horn pointed to the incisal angle.

The pulp space is much wider labiopalatally and the pulp space follows this outline.

Oval Type root canal.

The root apex is often tapered and very thin.

The canal is usually straight but may show a distal apical curvature.

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Mandibular Central and Lateral Incisors

CENTRAL

LATERAL

Average length is 21 mm, but the central incisor may be shorter than the lateral.

The pulp chamber is smaller replica of the upper incisors.

When the tooth has a single root canal it is normally straight but may curve to the distal.

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Mandibular Canine

Smaller than the maxillary canine.

The average length is 22.5 mm..

Rarely has 2 roots, but fewer of mandibular canine display the canal form with 2 separates apical formina.

Access cavity preparationAccess cavity preparation

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Endodontic Preparation of Endodontic Preparation of Maxil lary Anterior TeethMaxil lary Anterior Teeth

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Endodontic Preparation of Endodontic Preparation of Maxil lary Anterior TeethMaxil lary Anterior Teeth

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Adult toothAdult tooth

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Cavity Access. Canine

Extensive ovoid, funnel-shaped coronal preparation

Maxil lary Anterior TeethMaxil lary Anterior TeethERRORS in Cavity ERRORS in Cavity

PreparationPreparation

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Maxil lary Anterior TeethMaxil lary Anterior TeethERRORS in Cavity ERRORS in Cavity


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Endodontic Preparation of MandibularEndodontic Preparation of MandibularAnterior TeethAnterior Teeth

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Mandibular Anterior TeethMandibular Anterior TeethERRORS in Cavity PreparationERRORS in Cavity Preparation

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Mandibular Anterior TeethMandibular Anterior TeethERRORS in Cavity PreparationERRORS in Cavity Preparation

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Premolar TeethPremolar Teeth

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Maxil lary First Maxil lary First PremolarPremolar

Generally has 2 root with 2

canals, but in the case of 1 root has 2 canals which open in a common apical foramen.

Many types of canal

configurations.

Average length 21.5 mm.

The pulp chamber is wide B-P

with 2 distinct pulp horn.

M-D, the pulp chamber

is much narrower.

Endodontic Preparation of Endodontic Preparation of Maxil lary First premolar TeethMaxil lary First premolar Teeth

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Young tooth Adult toothYoung tooth Adult tooth

Maxil lary Second PremolarMaxil lary Second PremolarThe typical The typical second second premolar has onepremolar has one

root and one canal and sometimesroot and one canal and sometimes has an apical distal curvaturehas an apical distal curvature..

The pulp chamber is wider B-P and narrower M-The pulp chamber is wider B-P and narrower M-D and has 2 well define pulp hornsD and has 2 well define pulp horns..

The canal orif ice is directly in the centre of the The canal orif ice is directly in the centre of the toothtooth..

Average length: 21 mmAverage length: 21 mm..

Endodontic Preparation of Endodontic Preparation of Maxil lary Second premolar Maxil lary Second premolar

TeethTeeth

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Endodontic Preparation of Maxil lary Endodontic Preparation of Maxil lary Premolar TeethPremolar Teeth

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Maxil lary Premolar TeethMaxil lary Premolar TeethERRORS in Cavity ERRORS in Cavity


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Maxil lary Premolar TeethMaxil lary Premolar TeethERRORS in Cavity ERRORS in Cavity


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Mandibular Mandibular PremolarsPremolarsUsually has a single delicate root

with a mesial concavity, but

occasionally present a division of

the root in the apical half.

As a rule, both teeth have a single canal.

The coronal pulp is wide B-L with a large

buccal horn and a small lingual horn.

The shape of the canal is similar in first and second premolars.

Its buccolingual extension is broad until the

middle third of the canal, but is very narrow in

the apical third. Average Length: 22mm

Cavity AccessCavity Access•Because of the inclination of the crowns of Because of the inclination of the crowns of

mandibular teeth and the smaller lingual mandibular teeth and the smaller lingual cusp, the access opening should be cusp, the access opening should be

placed buccal to the central fissureplaced buccal to the central fissure. .

•The preparation is madeThe preparation is madeovaloval , corresponding to the, corresponding to the

shape of the root and canalshape of the root and canal..

Endodontic Preparation of Endodontic Preparation of Mandibular premolar TeethMandibular premolar Teeth

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Endodontic Preparation of Mandibular Endodontic Preparation of Mandibular Premolar TeethPremolar Teeth

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Mandibular Premolar TeethMandibular Premolar TeethERRORS in Cavity ERRORS in Cavity


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Mandibular Premolar TeethMandibular Premolar TeethERRORS in Cavity ERRORS in Cavity


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Molar TeethMolar Teeth

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Maxil lary First MolarsMaxil lary First MolarsGenerally three rooted with 3 canals. Addit ional Generally three rooted with 3 canals. Addit ional

canal is located in the MB rootcanal is located in the MB root. . Large pulp chamber, Large pulp chamber, tr iangular in shapetriangular in shape ,,

with the base toward the buccal and the apex with the base toward the buccal and the apex toward the l ingual surfacetoward the l ingual surface..

Slightly curved buccal rootsSlightly curved buccal roots..DP curvature of the MB rootDP curvature of the MB root..Apical-buccal curvature of theApical-buccal curvature of the

palatal root (55%palatal root (55%((

Average LengthAverage Length::MB: 20mmMB: 20mmDB: 19.5mmDB: 19.5mmP: 20.5mmP: 20.5mm

It has 3 or 4 pulp horn, the MB is the longest.

The floor of the pulp chamber is normally just apical to

the cervix and is rounded and convex to the occlusal.

The MB canal opening is closer to the buccal

wall than is the DB orifice.

The DB canal is closer to

the middle of the tooth than

to the distal wall, and is

the shorter and finest

of the 3 canals.

Maxillary First Molars

Endodontic Preparation of Endodontic Preparation of Maxil lary First molar TeethMaxil lary First molar Teeth

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Maxil lary Second MolarMaxil lary Second MolarIt is similar of the first molar:

Large pulp chamber.

Mesiobuccal, distobuccal, and palatal

roots, each with one canal.

Gradual curvature of all three canals.

“Flattened” triangular outline form.

The DB canal orifice is

nearer the centre of the

cavity floor.

Endodontic Preparation of Endodontic Preparation of Maxil lary Second Molar TeethMaxil lary Second Molar Teeth

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Endodontic Preparation of Maxil lary Molar Endodontic Preparation of Maxil lary Molar Teeth Teeth

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Locate canal orifices & obtain Locate canal orifices & obtain Straight-Line AccessStraight-Line Access Probing the Canal EntrancesProbing the Canal Entrances

After the roof of the pulp chamber has been penetratedAfter the roof of the pulp chamber has been penetratedand the access cavity prepared, the entrances to theand the access cavity prepared, the entrances to the

pulp canals must be probedpulp canals must be probed..

A hooked explorer can be used to determine ifA hooked explorer can be used to determine ifenough dentin has been removedenough dentin has been removed

The canal entrances are found by feeling with a thinThe canal entrances are found by feeling with a thin,,

stiff explorer. If the explorer sticks in a spot, a size 15stiff explorer. If the explorer sticks in a spot, a size 15Hedstrom file is used to verify that the spot is indeedHedstrom file is used to verify that the spot is indeed

the entrance to a root canal and not a perforation. Onlythe entrance to a root canal and not a perforation. Onlythen is the opening gently enlarged. Narrow root canalsthen is the opening gently enlarged. Narrow root canals

must first be enlarged coronally with a Hedstrom filemust first be enlarged coronally with a Hedstrom filebefore the deep preparation with before the deep preparation with Gates-Glidden burs Gates-Glidden burs cacan be startedn be started..

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Maxil lary Molar TeethMaxil lary Molar TeethERRORS in Cavity ERRORS in Cavity


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Maxil lary Molar TeethMaxil lary Molar TeethERRORS in Cavity ERRORS in Cavity


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Mandibular First Mandibular First MolarMolar

Usually has 2 roots one mesialUsually has 2 roots one mesial and one distaland one distal..

The Distal root is smoller and The Distal root is smoller and verticalvert ical..

Distal curvature of the mesial root Distal curvature of the mesial root (84% of the time) which has two (84% of the time) which has two canalscanals..

The distal canal is larger and more The distal canal is larger and more ovaloval..

The MB is the most diff icult canal The MB is the most diff icult canal to instrument because its tortuous to instrument because its tortuous pathpath..

Average Length: 21 mmAverage Length: 21 mm

Triangular outline form reflects the anatomy of the pulp chamber, with

the base toward mesial

and the apex toward the distal surface.

The cavity is primarily within the mesial half of the tooth but is extensive enough to allow positioning of instruments and filling materials.

Mandibular Second MolarMandibular Second Molar•It is smaller version of the f irst molar It is smaller version of the f irst molar

with an average length of 20mmwith an average length of 20mm..

•The mesial root has 2 canals and the The mesial root has 2 canals and the distal onedistal one..

•The mesial canals tend to fuse in the The mesial canals tend to fuse in the apical third to give rise to one main apical third to give rise to one main apical foramenapical foramen..

•Commonly has fused rootsCommonly has fused roots..

Endodontic Preparation of Endodontic Preparation of Mandibular Molar TeethMandibular Molar Teeth

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Endodontic Preparation of Mandibular Endodontic Preparation of Mandibular Molar TeethMolar Teeth

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Mandibular Molar TeethMandibular Molar TeethERRORS in Cavity ERRORS in Cavity


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Mandibular Molar TeethMandibular Molar TeethERRORS in Cavity ERRORS in Cavity


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Thank you

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Health & Medicine

012. access cavity preparation