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Endodontic Access
Cavity Preparation
PREPARED BY:
DR. HAMED AL-HADDAD
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Access Cavity Preparation
MAJOR OBJECTIVES
Straight-Line Access - 1
Conservation of Tooth Structure - 2
Unroofing of Chamber and Exposure of Pulp Horns - 3
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Endodontic Preparation of
Maxillary and mandibular
Anterior Teeth
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Maxillary Central
Incisor
All upper anterior teeth have
one root and one canal.
 Central incisor are large and on an average of 23 mm.
 It has a single canal and a single apical foramen.
 The canal form is usually Type I.
 The pulp in young patients normally has 3 pulp horns.
 The pulp chambers is noticeably wider in the
faciolingual direction than in the mesiodistal. 4

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Maxillary Lateral Incisor
It is shorter than central incisor.
Average length of 21- 22 mm.
It has a single canal and a single apical
foramen.
The canal form is usually Type I.
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. 5

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Maxillary Canine
It 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 I root canal.
The root apex is often tapered and very thin.
The canal is usually straight but may show a distal apical
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Mandibular Central and Lateral
Incisors
Average length is 21 mm, but the central
incisor may be shorter than the lateral.
The root canal morphology may be place
into 1 or 3 configurations. Type I canal
form is most prevalent, Types II and III
CENTRAL are less prevalent.
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.
LATERAL 7

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Mandibular Canine
Smaller than the maxillary canine.
The average length is 22.5 mm.
Type I canal form is most prevalent.
Rarely has 2 roots, but fewer of mandibular canine display
the Type IV canal form with 2 separates apical formina.
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Access cavity preparation
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Endodontic Preparation of
Maxillary Anterior Teeth
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Endodontic Preparation of
Maxillary Anterior Teeth
Adult tooth
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Cavity Access. Canine
Extensive ovoid, funnel-shaped coronal preparation
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Maxillary Anterior Teeth
ERRORS in Cavity
Preparation
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Maxillary Anterior Teeth
ERRORS in Cavity
Preparation
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Endodontic Preparation of Mandibular
Anterior Teeth
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Mandibular Anterior Teeth
ERRORS in Cavity Preparation
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Mandibular Anterior Teeth
ERRORS in Cavity Preparation
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Endodontic Preparation of
Maxillary and mandibular
Premolar Teeth
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Maxillary First Generally has 2 root with 2 
Premolar 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

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Endodontic Preparation of
Maxillary First premolar Teeth
Young tooth Adult tooth
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Maxillary Second Premolar
The typical second premolar has one 
root and one canal and sometimes
.has an apical distal curvature
The Type I canal form is prevalent with 
a frequency of 48%, approximately the same
.as types II and IV-VII combined
The pulp chamber is wider B-P and narrower M- 
.D and has 2 well define pulp horns
The canal orifice is directly in the centre of the 
.tooth
.Average length: 21 mm 

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Endodontic Preparation of
Maxillary Second premolar
Teeth
Young tooth Adult tooth
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25.
Endodontic Preparation of Maxillary
Premolar Teeth
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Maxillary Premolar Teeth
ERRORS in Cavity
Preparation
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Maxillary Premolar Teeth
ERRORS in Cavity
Preparation
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Mandibular
Premolars delicate root
Usually has a single
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

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Cavity Access
Because of the inclination of the crowns of •
mandibular teeth and the smaller lingual
cusp, the access opening should be
. placed buccal to the central fissure
The preparation is made •
oval , corresponding to the
.shape of the root and canal

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Endodontic Preparation of
Mandibular premolar Teeth
Young tooth Adult tooth
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Endodontic Preparation of Mandibular
Premolar Teeth
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Mandibular Premolar Teeth
ERRORS in Cavity
Preparation
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Mandibular Premolar Teeth
ERRORS in Cavity
Preparation
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Endodontic Preparation of
Maxillary and mandibular
Molar Teeth
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Maxillary First Molars
Generally three rooted with 3 canals. Additional 
. canal is located in the MB root
Large pulp chamber, triangular in shape , 
with the base toward the buccal and the apex
.toward the lingual surface
.Slightly curved buccal roots 
.DP curvature of the MB root 
Apical-buccal curvature of the 
(palatal root (55%
:Average Length 
MB: 20mm
DB: 19.5mm
P: 20.5mm

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Maxillary First Molars
.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

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Endodontic Preparation of
Maxillary First molar Teeth
Young tooth Adult tooth
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Maxillary Second Molar
:It 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

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Endodontic Preparation of
Maxillary Second Molar Teeth
Young tooth Adult tooth
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Endodontic Preparation of Maxillary Molar
Teeth
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Locate canal orifices & obtain
Straight-Line Access
Probing the Canal Entrances 
After the roof of the pulp chamber has been penetrated 
and the access cavity prepared, the entrances to the 
.pulp canals must be probed 
A hooked explorer can be used to determine if 
enough dentin has been removed 
,The canal entrances are found by feeling with a thin 
stiff explorer. If the explorer sticks in a spot, a size 15 
Hedstr6m file is used to verify that the spot is indeed 
the entrance to a root canal and not a perforation. Only 
then is the opening gently enlarged. Narrow root canals 
must first be enlarged coronally with a Hedstr6m file 
.before the deep preparation with Gates-Glidden burs can be started 

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Maxillary Molar Teeth
ERRORS in Cavity
Preparation
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Maxillary Molar Teeth
ERRORS in Cavity
Preparation
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Mandibular First
Molar has 2 roots one mesial 
Usually
.and one distal
The Distal root is smoller and 
.vertical
Distal curvature of the mesial root 
(84% of the time) which has two
.canals
The distal canal is larger and more 
.oval
The MB is the most difficult canal 
to instrument because its tortuous

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Average Length: 21 mm
The cavity is primarily within the mesial
half of the tooth but is extensive enough
to allow positioning of instruments and
.filling materials
Triangular outline form
reflects the anatomy of
the pulp chamber, with
the base toward mesial
and the apex toward the
.distal surface

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Mandibular Second Molar
It is smaller version of the first molar •
.with an average length of 20mm
The mesial root has 2 canals and the •
.distal one
The mesial canals tend to fuse in the •
apical third to give rise to one main
.apical foramen

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Endodontic Preparation of
Mandibular Molar Teeth
Young tooth Adult tooth
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Endodontic Preparation of Mandibular
Molar Teeth
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Mandibular Molar Teeth
ERRORS in Cavity
Preparation
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Mandibular Molar Teeth
ERRORS in Cavity
Preparation
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Thank you
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