Download - Endodntic Access
-
7/28/2019 Endodntic Access
1/35
ENDODONTICCAVITY PREPARATION
By
Dr.Mohamed khalefa
Prof. Of endodontics
Al-Azhar University.
-
7/28/2019 Endodntic Access
2/35
ENDODONTIC
CAVITY PREPARATION
Divided into:
* Intra-Coronal preparation.
* Intra-Radicular preparation.
-
7/28/2019 Endodntic Access
3/35
Endodontic cavity preparation
Objectives:
1) Obtaining direct line access
to both RC orifices & Apical
foramen.
2) Conservation of tooth
structure.
3) Reroofing of the Pulp
chamber.
-
7/28/2019 Endodntic Access
4/35
1) Intra-Coronal Cavity Preparation.
-
7/28/2019 Endodntic Access
5/35
Principles of Intra-Coronal Cavity
Preparation:
(I): Out line Form.
(II): Convenience Form.
(III): Removal of Remaining
Carious Dentin &
Defective Restorations.
(IV): Toilet of the Cavity.
-
7/28/2019 Endodntic Access
6/35
Principle I: Outline Form:
Endodontic cavity is correctlyshaped & positioned to establish
complete access for instrumenta-
tion from cavity margin to theapical foramen.
-
7/28/2019 Endodntic Access
7/35
N.B.
External outline form is established
by mechanically projecting the internal
anatomy of the pulp into
the external surface of the tooth.
-
7/28/2019 Endodntic Access
8/35
Factors affecting Outline Form
1) Size of the pulp chamber.
2) Shape of the pulp chamber.
3) Number, Position &
Curvature or Direction
of each individual root canal
4) Age of the patient.
-
7/28/2019 Endodntic Access
9/35
-
7/28/2019 Endodntic Access
10/35
Principle II: Convenience Form:
I .e. Modification of theCavity Outline Form to
establish greater conven-
-ience in preparation aswell as obturation of the
root canals.
-
7/28/2019 Endodntic Access
11/35
Benefits of Convenience Form:
1) Unobstructed access to thecanal orifice & searching for
extra canal.
2) Direct access to the apicalforamen.
3) Complete authority over the
enlarging instruments.
4) Cavity expansion to accommodate
filling techniques
-
7/28/2019 Endodntic Access
12/35
Principles III: Removal of the Remaining
Carious Dentin & Defective Restorations:
I .e.All carious & loosed or fracturedrestorations must be removed &
the cavity is sealed with hardrestoration before Endodontic
cavity preparation is established.
-
7/28/2019 Endodntic Access
13/35
Benefits of Removal of Carious Dentin
& Defective Restorations:1) To eliminate mechanically as many micro-organismsas possible from the interior of the tooth.
2) To eliminate the discolored tooth structure.
3) To eliminate the possibility of micro-organisms coming
with saliva leakage through defective restoration.
4) To avoid detached tooth or restoration particles from
entering & closing the root canal.
-
7/28/2019 Endodntic Access
14/35
Principle IV: Toilet of the cavity:
(Irrigation of the Cavity)
All the detached carious dentin, debris & necrotic
material must be removed from the pulp chamber
before the Radicular preparation is begun because
they may:
1) Obstruction of the canal during enlargement.
2) Increase bacterial possibilities in the canal(RCs infection).
3) Discoloration of the crown.
-
7/28/2019 Endodntic Access
15/35
Access Cavity
Preparation
for Anterior
Teeth
(Step by Step)
-
7/28/2019 Endodntic Access
16/35
Maxillary Incisors
-
7/28/2019 Endodntic Access
17/35
Mandibular Incisors
-
7/28/2019 Endodntic Access
18/35
Maxillary Cuspid (Canine)
-
7/28/2019 Endodntic Access
19/35
Mandibular Cuspid (Canine)
-
7/28/2019 Endodntic Access
20/35
-
7/28/2019 Endodntic Access
21/35
-Maxillary & Mandibular premolar : the outlineform prepared in the center of the occlusal surface
as OVAL shape .
-
7/28/2019 Endodntic Access
22/35
-
7/28/2019 Endodntic Access
23/35
Maxillary molars The access preparation on the occlusal surface as a triangular
shape , with the base toward the buccal surface and the apex
toward the palatal surface .
The first penetration of enamel is made using round bur at the
central groove midway between the mesial marginal ridge & the
oblique ridge and the roof of the pulp chamber is removed
completely . The access preparation is to be enlarged to accommodate the
fourth canal in the MB root .
-
7/28/2019 Endodntic Access
24/35
Mandibular molars :The access preparation on the occlusal surface as a
triangular shape in case of 3 canals ,or rectangular shape
in case of 4 canals . The base of the triangle is towared themesial surface and the apex toward the distal .
-
7/28/2019 Endodntic Access
25/35
-
7/28/2019 Endodntic Access
26/35
-
7/28/2019 Endodntic Access
27/35
-
7/28/2019 Endodntic Access
28/35
-
7/28/2019 Endodntic Access
29/35
-
7/28/2019 Endodntic Access
30/35
-
7/28/2019 Endodntic Access
31/35
AccessPreparation
AccessOpening
ENDO ACCESS BUR(Dr Howard Martin)
Grain : Coarse
Shank : FG
-
7/28/2019 Endodntic Access
32/35
AccessPreparation
Access Opening
Orifice Location
Pathfinder orendodontic
explorer is used forReaching, Feeling,and Digging atcanal opening.
Orifice Loction :
-
7/28/2019 Endodntic Access
33/35
Errors in coronal cavity preparation of
maxillary & mandibular anterior teeth :
1-discoloration of the crown which caused by
failure to remove pulp debris .
2- failure to explore the second canal which
caused by inadequate inciso-cervical extension of
coronal cavity .
3-perforation at the labio-cervical caused byfailure to complete extension towered incisally .
4- gouging of labial & distal wall caused by failureto correct angulations of bur during access cavity.
5- ledge formation at apico-distal curvecausedbyusing incurved instruments .
-
7/28/2019 Endodntic Access
34/35
Errors in cavity preparation of maxillary &
Mandibular premolars
1- Under or over extended preparation .
2- perforation at mesio-cervical indentation .
3-failure to explore second or third canal .
Molar teeth1- Perforation into furcating region .
2- failure to detect fourth canal .
3-perforation at mesio-cervical caused by failure
to orient bur with long axis of molar severelytipped to mesial .
-
7/28/2019 Endodntic Access
35/35