The document discusses guidelines for access cavity preparation in endodontics. It defines access cavity preparation as coronal preparation that provides unobstructed access to canal orifices and straight line access to the apex. It outlines principles of conservation of tooth structure, prevention of perforations, and maximum visibility. It describes factors that determine the outline form such as pulp chamber size, shape, and number/direction of canals. Common tools used for access cavity preparation are also listed. The document provides detailed descriptions of accessing different types of teeth based on their anatomy. It emphasizes removal of caries and defective restorations to eliminate bacteria and possibility of coronal leakage. Overall, the document provides a comprehensive overview of guidelines and procedures for access

1. •Guided by.
•Dr. Arun verma
•Dr. Swapan rai
•Dr.Ashutosh Pratap
presented By.
Navendu singh.
Batch (2018-19)

2. Access cavity preparation is
defined as endodontic coronal
preparation which enables
unobstructed access to the
canal orifice, a straight line
access to the apical foramen,
complete control over
instrumentation and
accommodation obturation
technique.

3. According to vertucci :-
1. Removal of all carious tooth
structure
2. Conservation of sound tooth
structure
3. Complete deroofing of the pulp
chamber
4. Removal of coronal pulp tissue
5. Location of all root canal orifices
6. Straight line access to the root
canal

4. Conservation of tooth
structure.
Minimal weakening of tooth.
Prevention of perforations.
Maximum visibility.
Location of canal.

5. 1. Outline form.
2. Convenience form
3. Removal of remaining carious
dentin and defective
restoration.
4. Toilet of cavity.

6. Established by mechanical
projecting the internal anatomy to
the external surface.
Three factors regulating the
outline form
1. size of pulp chamber:
young patients– extensive.
Old patients– limited.

7.  Shape of pulp chamber.
anterior– triangular
Premolar– oval or ovoid
molar– triangular
Number and direction of root canal.

8. Convenience form is defined
as that form of cavity
preparation that allows
adequate observation,
accessibility and case of
operation in preparing and
restoring the cavity.

9. Reasons of removing caries and defective
restoration
1. Elimination of bacteria
2. Elimination of discolored tooth
structure.
3. Elimination of the possibility of
coronal leakage .

10. All caries, calcified debris and necrotic
material should be removed by
irrigation from the pulp chamber before
radicular preparation is begun to avoid
obstruction of the root canal.

11.  Front surface mouth mirrors
Airotar and low speed rotary hand pieces
Burs: round carbide burs( no-2,no4 and no6) for caries
removal and defining the external outline shape

12. Diamond burs with round cutting ends for axial
wall extension.
Fissure carbide burs and diamond burs with the
safety tips.

13. Endodontic spoon excavator
Endodontic explores eg: DG-16

14. The following clinical observations are
indicative of an unusual root canal anatomy
1. Presence of an additional cusp
2. Abnormality in the size and shape of the tooth.
Major principle of Endodontic cavity outline
form : the internal anatomy of the tooth (pulp)
dictates the external outline form

15. 1. Rotated teeth/malpositioned teeth
2. Tipping/mesial tilting of the tooth
3. Grossly decayed teeth
4. Teeth with fill-coverage restoration
5. Abutment teeth of fixed prostheses
6. Teeth with extensive calcification

16. Mesiodistal tilt of the tooth
Size and shape of the pulp
chamber
Thickness of the roof of the
pulp chamber
Presence of pulp stone
Extent of the root and canal
Curvature.

17. A. Complete removal of carious tooth structure
and other restorative material
 while preparing the access cavity in a cariously
involved tooth, start removing the carious tooth
structure irrespective of the location of the carious
lesions.

18. B. Complete deroofing and removal of
dentinal shoulder .

19. C. Evaluation of the cementoenamel junction and
root canal orifices.
. The following dentinal shoulder should be taken
into consideration achieve straight line access.
Mandibular anteriors– lingual shoulder
Maxillary anteriors-- palatal shoulder
Premolar--- mesial and distal shoulder
Mandibular molar– mesial and distal shoulder
Maxillary molar– mesial and buccal shoulder.

20. Removal of the coronal tooth
structure is necessary to allow
complete freedom of endodontic
instruments in the coronal
cavity and direct access to the
apical canal this is especially
true when the root is severely
curved or leaves the chamber
at an obtuse angle.

21. Complete deroofingd of the pulp chamber and
elimination of dentinal shoulder between root canal
orifices will aid in in the achievement of straight line Access.
Mouse hole effect: if the lateral wall of the cavity has been
sufficient exteded and the pulpal horn portion of the orifices
still remains in the wall,the orifices will have the
appearance of a tiny mouse hole “This features occurs due to
the extention of the canal orifices into the axial wall .

22.  Law of centrality – The floor of the pulp chamber is
always located in the center of the tooth at the level of
the CEJ.
Law of concentricity- The wall of the pulp
chamber are always concentric to the external
surface of the tooth at the level of the CEJ.
Law of orifice location- The orifices of the root
canal are located at the junction of the walls and
the floor.

23.  Law of symmetry.
1. Except for Maxillary molars,the orifices of the
canal are equidistant from a line drawn in a
mesiodistal direction through the pulp
chamber floor.
2. Except for Maxillary molar the orifices of the
canal lie on a line perpendicular to the a line
drawn in a mesiodistal direction across the
center of the floor of the pulp chamber.

24. 2. The orifices of the root canal are located at angle in the
floor wall junction
3.The orifices of the root canal are located at the terminus
of the root development fusion lines.
Law of color changes.
1. Enamel – white
2. Dentin-yellow
3. floor of the pulp chamber- Gray
4. Root canal orifices– Dark gray or black
5. Pulp stone—pearly white /dark yellow

25. The entrance is always made through the lingual surface in
the middle one-third region.
 Initial penetration is made with a round ended tapered
fissure bur. only enamel is penetrated. The bur should not
be forced but allow to cut it on its own way.
 The pulp chamber In Maxillary central incisor is located in
the center of the crown. The pulp chamber usually follows
the contours of the crown and has three pulp horn the
correspond to the developmental mamelons in young tooth.

26. The enamel is penetrated in center
of the lingual surface at an angle
perpendicular to it with a no-04
round bur in high-speed contra
angle.
A drop of the bur into the chamber
may be felt if the chamber is large
enough the overhanging enamel
and dentin of the palatal roof of the
pulp chamber are removed
including the pulp horns.

27. Maxillary incisors the access
shaped is slightly triangular
With the base of triangle
toward the incisal edge.
The access opening of
Maxillary lateral incisor is
similar to that for the
maxillary central incisors. but
it is smaller and usually more
ovoid.

28.  The access opening for the maxillary canine is
basically the same as that for the maxillary central
&lateral incisor.
The only variation is that the shape of the access
opening is circular to ovoid as directed by pulp
chamber anatomy.

29.  Using a no-02 round carbide bur in a high speed contra
angle one penetrates the enamel in the center of the
occlusal surface between the buccal and lingual cusp
and the bur is directed in to the long axis of the tooth
Then a bur aligned to the long axis of the tooth is used
to penetrate through the dentin into the pulp chamber.
The operator feels drop into the pulp chamber when the
chamber is large.
The access opening for Maxillary second premolar is
basically same as that of maxillary first premolar.

30.  border of the access cavity of maxillary premolar
should not extend beyond half the lingual incline of
the facial cusp and half the facial incline of the
palatal cusp.

31. The enamel is penetrated with a high-speed bur by
positioning the instrument in the central fossa and angling
it toward the palatal root the bur is directed toward the
palatal canal ,where the pulp chamber of this tooth is
largest.
Cutting occlusally from within the pulp chamber one
removes the bulk of the roof of the pulp chamber.
A tapered-cylinder self-limiting diamond bur is used to
removed the remaining roof of the pulp chamber.
The triangular access preparation in maxillary molar is
modified Into a rhomboidal shape whenever the MB-2 canal

32. The wall of the access cavity should be confluent with
the wall of the pulp chamber and slightly divergent
toward the occlusal surface.
The access opening is usually triangular with the
round corners extending toward but not including the
MB cusp tip, marginal ridge and oblique ridge.
This triangular preparation permits direct access to
the root canal orifices.
The maxillary second molars access opening is
basically the same as that for the maxillary first molar
with the variation that anatomic structure dictates.

34.  The average length of this tooth is
21.5mm The access opening of the
mandibular Central incisors is made
in similar manner as for the maxillary
anterior teeth with the variations that
it’s smaller size demand.
The shape of access cavity of the
mandibular incisors is long and oval
with its greatest dimension oriented
incisogingivally .

35.  in lateral incisor The access opening is made in the
same manner as for the mandibular Central incisors.

36. Access opening of the
mandibular canine is made in
similar manner as for the
maxillary canine with the
Variation Dictated by a
smaller anatomic dimension.
 The mandibular canine
resembles the maxillary
canine but it is smaller in all
dimension.
The pulp chamber is narrow
mesiodistally. When viewed
labiolingually.

38. The tooth average is 22.5mm
The mandibular first premolar has about 30⁰
lingual tilt of the crown to the long axis of the
root.
The procedure is the same as maxillary
premolars. The resulting access cavity is ovoid,
with the wall of the pulp chamber confluent
with the access cavity and divergent occlusally.

39. The access opening of mandibular second premolar
is basically the same as for the mandibular first
premolar, except the enamel penetration is initiated
in the central fossa.

40. The average length of the mandibular first molar is
21.5mm and second molar is 20mm.
In mandibular first molar usually two roots are present
one mesial and distal. A third roots is also found in
some cases either distally or mesially (5.3%) and is
refers as the third radix Entomolaris
mesial root : usually two canals that exist in two
foramina in 41% of cases.
Two canals that coalesce to exit in one foramen in
28%cases.

41. two canals that coalesce to form one canal and
bifurcate and exist in two foramina in 13% cases.
One canal that exist in one foramina in 12% cases.
 one canal that bifurcated and exist in two foramina in
8% cases.
> The access opening of mandibular first molar
follows that anatomic feature of the pulp chamber.
The enamel and dentin is penetrated in central fossa
with the bur angled toward in distal root. Where the
pulp chamber is large. The preparation follow the
procedural outline of maxillary molar.

42.  distal root : one canal existing in one foramina in
70% cases.
The access opening is usually trapezoidal with round
corner or rectangular if a second distal canal id
present.

43. The access opening for the mandibular second molar is
created as for the mandibular first molar, with the
variation that a smaller tooth demand. Because of the
Buccoaxial inclination.
The access opening of mandibular third molar is
created as for the mandibular first and second molar
with the variations that anatomic structure dictates.

44.  GROSSMAN’S 14TH EDITION
 RAMYA RAGHU & RAGHU
SRINIVASAN.
BRITISH DENTAL JOURNAL.
 GOOGAL.COM
COLUMBIA.edu

45. THANK YOU