Access cavities Flashcards
Define “access cavity”
Opening prepared in a tooth to gain entrance to the root canal system.
Define “working length”
The distance from a coronal reference point to the point where instrumentation/obturation terminates in root canal.
List the 4 steps to access cavity
- Pre-access analysis
- Removal of pulp chamber roof completely.
- Identification of pulp chamber, pulp floor and root canal orifices
- Instrumentation of the root canals.
Describe the pre-access analysis step
- Know root anatomy and match access cavity.
- Steps: 1) Radiographic examination, 2) periodontal probing to located CEJ.
Describe the removal of pulp chamber roof completely step
- Start in largest pulp horn
- Make access wide enough for straight-line access to all roots
- Access of maxillary incisors
- use Endo Access Bur to enter pulp chamber
- Use Endo Z bur to refine access cavity once pulp chamber is reached.
- Use No. 17 explorer to find pulp horns
- Use Gates-Glidden burs or slow-speed long shank burs to remove palatal hump
- Use DG No. 16 Explorer to check for straight-line access to orifices
What to use for identifying pulp chamber, pulp floor, and root canal orifices
Use Krasner & Rankow Laws
Purpose of endo access bur?
Used for initially entering pulp chamber
Purpose of endo Z burr
Used to widen access cavity once pulp chamber has been reached. Non-cutting end.
Purpose of No. 17 Explorer
Use to find pulp horns
Purpose of DG No. 16 Explorer
Use to check for straight-line access to orifices
Purpose of Gates-Glidden burs
Use to clear pulp horns and achieve straight-line access to canal. Also used in CORONAL zone of canal only.
Purpose of slow-speed long shank burs
Used to clear pulp horns and achieve straight-line access to canal. Used to smooth and finalize margin of access cavity.
