Endo- SLC-1

Question 1

Access Cavity

Answer 1

The opening prepared in a tooth to gain entrance to the canal system.

Question 2

A relatively straight line access during endodontic therapy will facilitate ___ of the canal.

Answer 2

cleaning and shaping (C+S)

Question 3

Purposes of an Appropriate Access Cavity

Answer 3

ID PS

1. Prevent interference by the walls of the preparation on the shaft of the endodontic instrument.
2. Facilitates the debridement of the canals.
3. It allows the placement of instruments needed during the obturation.
4. Provides pulp chamber space and a positive seat for temporary filling material.

Question 4

Armamentarium for access cavity prep.

Answer 4

1. Slow and high speed round burs (#2, 4)
2. Endodontic explorer and a mouth mirror
3. Irrigating syringe and sodium hypochlorite (NaOCl)
4. Pre operative x-ray and bitewing if necessary

Question 5

Access cavity prep is done in _______ steps.

Answer 5

Two steps:

i) Penetration
ii) Funneling

Question 6

Access cavity prep: Step 1

Answer 6

1. Penetration:
   - done with the high speed,
   - drilling through enamel until the pulp chamber is reached.

Question 7

Access cavity prep: Step 2

Answer 7

2. Funneling:
   - done with the slows peed and/or high speed depending on the tooth that you are working on.

• The purpose is to enlarge the size of the penetration to the same size of the pulp chamber.
• Funnel the access by shaving tooth structure in an incisal or occlusal direction.
• Extend the preparation to include the pulp horns

Question 8

Access cavity prep procedure: Anterior teeth

Answer 8

1. Penetrate the enamel just incisal to the cingulum with a high-speed #2 or #4 round bur until the pulp chamber is reached.
2. • With the high-speed handpiece and a round bur one size larger than the one you were originally using, increase the size of the penetration.
   • Remove triangle # 1 which is mainly enamel.
3. With the long-shank slow-speed round bur (#2 or #4 round bur) remove triangle #2 (mainly dentin), which is located behind the cingulum

Question 9

Shape of the access cavity: Maxillary Centrals (#8, #9)

Answer 9

Triangular

Question 10

Shape of the access cavity: Maxillary Laterals (#7, #10)

Answer 10

Roughly ovoid

Question 11

Shape of the access cavity: Mandibular Centrals (#24, #25)

Answer 11

Ovoid or Elliptical

Question 12

Shape of the access cavity: Mandibular Laterals (#23, #27)

Answer 12

Oval

Question 13

Shape of the access cavity: Maxillary Canines (#6, #11)

Answer 13

Oval

Question 14

Shape of the access cavity: Mandibular Canines (#6, #11, #22, #27)

Answer 14

Oval

Question 15

On lower incisors, why should the preparation be extended into the cingulum area?

Answer 15

On a lower incisor, the preparation must be extended well into the cingulum area to provide access to the lingual portion of the canal to locate the opening of a possible second canal.

Question 16

Why is the access oval for canines? (#6, #11, #22, #27)

Answer 16

Maxillary and mandibular canines are wider bucco-lingually, so the access is oval

Question 17

Access cavity prep (general/common) procedure: Posterior teeth

Answer 17

1. Drill into the central fossa with a high speed #4 or #6 round bur until you feel that you went through the ceiling of the chamber.
2. Enlarge the preparation by `peeling-off’ the roof of the pulp chamber with a round bur (#4, #6) then refine the walls with a “Endo-Z” bur

Question 18

The pulp of maxillary premolars (#4, #5; #12, #13) is in a _________ direction.

Answer 18

bucco-lingual

Question 19

Shape of the access cavity: Maxillary premolars (#4, #5; #12, #13)

Answer 19

Ovoid

Question 20

Shape of the access cavity: Mandibular premolars (#20, #21; #28, #29)

Answer 20

Ovoid

Question 21

Location of pulp chamber of Maxillary premolars (#4, #5; #12, #13)

Answer 21

e pulp chamber is located centrally along a ‘line’ joining the tip of the buccal and lingual cusp.