MCQs in Endodontics

Chapter 10: Obturation

1 - A well-litted root canal:

  1. prevents microbial leakage.
  2. exhibits radiopacity.
  3. extends beyond the apical constriction.
  4. needs no root canal cement.








The answer is: A


2 - Appropriate time for obturation is:

  1. when the canal is free of hemorrhage.
  2. when the canal has ceased to exude tissue fluids.
  3. when the tooth is symptomati
  4. before post cementation.






The answer is: C


3- Rool-lilling materials must be

  1. low cost.
  2. easily dissolve
  3. rigi
  4. biocompatible






The answer is: D

4- Root canal cements should:

  1. be bactericidal.
  2. be bacteriostatic.
  3. set quickly.
  4. be radiolucent.






The answer is: B


5- Tug-back is achieved and the canal is ready for filling:

  1. when the gutta-percha has extended beyond the apex.
  2. when the gutta-percha is easily removed from the root canal.
  3. when the gutta-percha placed to apical constriction exhibits resistance on removal.
  4. after cementation.







The answer is: C


6- Calcium hydroxide root canal sealers:

  1. are the most biocompatible.
  2. are irritating to the periapical tissue.
  3. should be used exclusively.
  4. prevent postobturation pain.






The answer is: A


7- The "string-out test" for root canal sealer is achieved when, using a spatula, the cement can be raised from the glass slab:

  1. 4 inches
  2. 2 inches.
  3. 1 inch.
  4. 3 inches.







The answer is: C


8- On preparing the root canal with a protaper F2 file, 1mm of the GP cone is cut so as to fit the canal with friction. The diameter of the apical region is:

  1. 29mm
  2. 30mm
  3. 31mm
  4. 32mm







The answer is: C


9- If a patient has gingival recession, how far should the gutta percha be trimmed back before sealing the coronal portion:

  1. 1mm below the level of recession
  2. 1mm below the ACJ
  3. 1mm below the canal opening
  4. 1mm below the roof of the pulp chamber






The answer is: A