1. Endodontic Access Cavity Preparation

2. The main function of an access cavity is
1- To create an unimpeded pathway to the pulp space and the apical foramen of the tooth.
2- Straight-Line Access
3- prevention of iatrogenic problems and avoidance of technical failure of root canal treatment.
4- Give good vision
5- To locate all root canal orifices
6- To conserve sound tooth structure

3. Endodontic Preparation of Maxillary Anterior Teeth

4. Access cavity preparation
old
young

5. Endodontic Preparation of Maxillary Anterior Teeth
Adult tooth

6. Cavity Access. Canine Extensive ovoid shape inciso-cervical, funnel
shaped coronal preparation
The canal is usually straight but may show a distal apical curvature.

7. 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 the outline.
Oval root canal in cross section.

8. Maxillary Anterior Teeth ERRORS in Cavity Preparation
In case of 1-crowned tooth 2-miss understanding of the tooth anatomy
3-tited teeth.

9. In crown
1-Missed canal
2-Labial perforation
3-Lateral perforation
In root
4-Ledge formation
5-Ziping
6-Apical transportation
7-Apical perforation

10. Maxillary Anterior Teeth ERRORS in Cavity Preparation

11. Endodontic Preparation of Mandibular Anterior Teeth

12. Mandibular Anterior Teeth ERRORS in Cavity Preparation

13. Mandibular Anterior Teeth ERRORS in Cavity Preparation

14. Should be removed to avoid stressed instrument
And discoloration

16. Factors affecting the access cavity design: 1- Age of the patient
2- Number of canals
3- Curvature of the canal
4- Tooth type or number
tapered or cylindrical fissure burs, ISO 010
or ISO 012, are used in the initial stages of access preparation to establish the correct outline form.
For penetrating ceramic or composite materials, diamond-coated burs are needed.

18. Round burs, normal and extra-long, in a contra-angle hand piece are used to lift the roof off the pulp chamber and eliminate overhanging dentine. If a standard length bur is too short, burs with longer shanks, up to 28 mm, are available. The longer and smaller sizes of burs may be used to remove dentine when opening calcified canals.
Safe-ended burs following initial access to the pulp space, a safe-ended or non-cutting tip, tapered diamond can be used to remove the entire roof of the pulp chamber. The non-cutting tip prevents perforation of the pulpal floor.

19. Maxillary First Premolar
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.
The pulp chamber is wide B-P
with 2 distinct pulp horn.
M-D, the pulp chamber
is much narrower.

20. Endodontic Preparation of Maxillary First premolar Teeth
Young tooth Adult tooth

21. Maxillary Second Premolar
The typical second premolar has one root and one canal and sometimes has an apical distal curvature. 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.

22. Endodontic Preparation of Maxillary Second premolar Teeth
Young tooth Adult tooth

23. Endodontic Preparation of Maxillary Premolar Teeth

24. Maxillary Premolar Teeth ERRORS in Cavity Preparation

25. Endodontic Preparation of Mandibular premolar Teeth
Young tooth Adult tooth

26. Cavity Access
Because of 1-the inclination of the crowns of mandibular teeth 2- 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.

27. Endodontic Preparation of Mandibular Premolar Teeth

28. Mandibular Premolar Teeth ERRORS in Cavity Preparation

29. Mandibular Premolar Teeth ERRORS in Cavity Preparation

30. Endodontic Preparation of Maxillary and mandibular Molar Teeth

31. 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%)

32. It is very important to preserve the developmental lines that connect with the canal orifices. It’s dark lines
in the floor of
the pulp chamber
of teeth.

33. 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 mostly 2 canal MB1 + MB2.
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.

34. Operating microscope is used to locate the canal orifices

35. Endodontic Preparation of Maxillary First molar Teeth
Young tooth Adult tooth

36. accessory canal in any teeth and every were
Always seek for
accessory canal in any teeth and every were

37. 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. Some time 2 canals

38. Endodontic Preparation of Maxillary Second Molar Teeth
Young tooth Adult tooth

39. Endodontic Preparation of Maxillary Molar Teeth

40. 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 8 or 10 file is used to verify that the spot is indeed the entrance to a root canal and not a perforation. Then is the opening gently enlarged. Narrow root canals must first be enlarged coronally with a Hedstrom file before the deep preparation with Gates-Glidden burs can be started.

42. Maxillary Molar Teeth ERRORS in Cavity Preparation

43. Maxillary Molar Teeth ERRORS in Cavity Preparation

44. Mandibular First Molar
Usually has 2 roots one mesial 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 path and narrow.

45. 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 in case of 3 canals, square to rectangular in case of 4 canals reflects the anatomy of the pulp chamber, with the base toward mesial and the apex toward the distal surface.

46. Endodontic Preparation of Mandibular Molar Teeth
Young tooth Adult tooth

47. Endodontic Preparation of Mandibular Molar Teeth

48. Mandibular Molar Teeth ERRORS in Cavity Preparation

49. Mandibular Molar Teeth ERRORS in Cavity Preparation

55. Thank you