Dr. Özkan ADIGÜZEL

1. ACCESS CAVITY
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2. Aims of Endodontic treatment
• Biologic aims
a) To remove all the debris support to bacterial growth
b) To destroy all micro--organisms from the root canal
• Mechanical aims
c) Prepare root canal space for three dimensional filling
d) To obturate prepared canal in order to completely
seal from both apical (at the cemento-enamel
junction) and coronal seal
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3. Steps in root canal therapy
1. Patient selection
2. Tooth selection
3. Isolation
4. Access cavity
5. Canal irrigation
6. Working length
7. Canal preparation
8. Trial filling
9. Canal obturation
10. Crown restoration
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4. Preparation of tooth
1
1. Remove carious dentine and bad restorations
2. Restore it with GIC
3
3. Isolate the crown
4. Disinfected the crown and immediate
environment
5. Adhere to surgically clean technique
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5. Objectives of Access cavity
1. To remove the entire roof of the pulp chamber so that the
pulp chamber can be irrigated and cleaned the canal
entrance exposed.
2. To avoid damage to floor of the pulp chamber for located
root canals orifices. Natural floor is having funnel shape
orifice tends to guide an instrument in to the canal.
3. To achieve direct--line access to the apical third of the root
canals for proper instrumentation, irrigation, shaping,
cleaning, drying and obturation.
4. To enable a temporary seal to be placed.
5. To conserve as much sound tooth tissue as possible
compatible with above.
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6. Guide lines for Access cavity
preparation
1. Visualization of the internal anatomy
2. Evaluation of the cemento-enamal junction and
occlusal anatomy
3. Removal of all defective restoration and caries
4. Removal of unsupported enamel
5. Creating direct line access to apical third
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7. Guide lines for Access cavity
preparation
6. Delay of isolation until all the canal orifices located
7. Location, flaring and exploration of all the canal
orifices
8. Inspection of the pulp chamber using magnification
and adequate illumination
9. Tapering cavity walls and
10. evaluation of space adequacy for coronal seal
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8. Visualization of the internal
anatomy
X-ray
• Position of the pulp chamber
• Degree of calcification
• Number of roots
• Number of root canals
• Approximate canal length
Examination coronal and cervical anatomy
palpation along the attached gingiva for root location &
direction
Assessments choose the direction of the initial bur penitration
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9. Evaluation of the cemento--enamal
junction and occlusal anatomy
• Except maxillary molars, canal orifices are
equidistant from line drawn in mesiodistal
direction through the pulp chamber floor.
• Except maxillary molars, canal orifices lie on a
line perpendicular to a line drawn a mesiodistal
direction across the centre of the pulp chamber
floor.
• the pulp chamber floor is always darker in color
than the walls
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10. Evaluation of the cemento--enamal
junction and occlusal anatomy
• The orifices of the root canals are always located
at the junction of the wall and the floor
• The orifices of the root canals are always located
at the angles in the floor- wall junction
• The orifices of the root canals are always located
at the terminus of the root developmental fusion
lines
Mandibular 2nd and 3rd molars are prone to have C
shape canal
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11. Removal of all defective restoration
and caries
• All defective restoration should be removed before
entry into the pulp chamber
– Open preparation is much easier to locate, irrigation,
cleaning , shaping, drying and obturation.
– Restorative debris easily lodged in to the canals
• All caries should be remove before entering to the
pulp chamber
– Prevent contamination of the canals
– Prevent contamination of the accidental perforations
– Prevent leaking of irrigating solutions
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12. Removal of unsupported enamel
• Preparation of access cavity results weaker
crown
• This will prone to fractures
• After finishing access cavity clinician should
remove all unsupported enamel to assess
restorability and to prevent tooth fracture
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13. Creating direct line access to
apical third
• Sufficient tooth structure should be removed
from the pulp chamber wall to allow instruments
to be placed easily into each canal orifices without
interference from the canal walls
• Root canal walls should guide the files not the
pulp chamber wall
• If not procedural error may formed like ledge
formation, instrument separation, apical
transportation
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14. Delay of isolation until all the
canal orifices located
• For crowded, rotated, fractured, calcified, heavily
filed and crown and angled teeth should not isolate
before locating canal orifices
• It is difficult to locate canal orifices for above
mention teeth
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15. Location, flaring and exploration
of all the canal orifices
• With sharp endodontic explorer locate the
canals
• With pre-curved small K file explore the canal
• Until working length is determined instrument
should be operated within the confines of the
canal system
• Always a lubricating agent should be used
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16. Inspection of the pulp chamber
using magnification and
adequate illumination
• To see internal land mark and color changes
magnification and light is essential
• Operating microscope is the best
• At least magnifying loupes should be used
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17. Tapering cavity walls and
• Access cavity should have widest at occlusal
surface
• Occlusal forces not push the temporary
restoration into the cavity
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18. evaluation of space adequacy for
coronal seal
• At least 3.5mm thick temporary material is
needed for proper coronal seal
• Glass ionomer and light cure composite
restoration enhance the coronal seal
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19. Non-vital tooth Initial access
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20. Cutting into the pulp Removal pulp roof
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21. Use of Briault probe
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22. Extension of access cavity
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23. Completed access cavity.
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24. Use of barbed broach Root canal irrigation
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25. Direct line access
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26. Prepare coronal part with gate bur
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27. Tooth length Working length
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28. Non--vital posterior tooth
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29. Initial access Access to the pulp
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30. Withdrawal action Smoothening walls
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31. Orifice enlargement
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32. Remove interferences Uses of gates bur
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33. Preparation of coronal two third
Number 3 Gates bur
Number 2 Gates bur
Number 1 Gates bur
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34. Direct line access Anti-curvature filing
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35. Access cavity Average length – 22.5mm Prepared canal
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36. Access cavity Average length – 22.0mm Prepared canal
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37. Access cavity Average length – 26.5mm Prepared canal
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38. Access cavity Average length – 20.6mm Prepared canal
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39. Access cavity Average length – 21.5mm Prepared canal
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40. Access cavity Average length – 20.8mm Prepared canal
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41. Access cavity Average length – 20.0mm Prepared canal
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42. Access cavity Average length – 20.9mm Prepared canal
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43. Access cavity Average length – 25.6mm Prepared canal
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44. Access cavity Average length – 21.6mm Prepared canal
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45. Access cavity Average length – 22.3mm Prepared canal
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46. Access cavity Average length – 21.0mm Prepared canal
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47. Access cavity Average length – 19.8mm Prepared canal
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48. Access cavity Average length – 22.5mm Prepared canal
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