MCQs in Endodontics

Chapter 24: Endodontic failure and retreatment

 

 1- Which of the following is not significant in evaluating treatment results:

  1. The extension of filling material.
  2. The location of the treated tooth.
  3. The obturation quality.
  4. The presence of periapical pathosis before treatment.

 

 

 

 

 

 

The answer is: B

 

 2- In evaluating treatment results, the consensus on the minimum period of observation was:

  1. at least 6 months.
  2. 6 months to a year.
  3. at least 1 year.
  4. at least 2 years.

 

 

 

 

 

 

The answer is: C

 

 3- Pitfalls associated with radiographic interpretation of success or failure include:

  1. change in angulation.
  2. lack of radiographic changes.
  3. personal bias.
  4. All of the above.

 

 

 

 

 

 

 The answer is: D

 

4- Which of the following statements concerning radiographs is true:

  1. Swelling and pain, necessitating incision and.drainage, may occur without any radiographic indication.
  2. At least 30% of the bone must be decalcified for a lesion to be evident radiographicaily.
  3. The size of the lesion on the radiograph is indicative of the actual amount of bone destruction.
  4. Complete denudation of bone over the root apex is always evident radiographicaily.

 

 

 

 

 

 

The answer is: A

 

 5- Undcrextending the access cavity preparation may lead to:

  1. a missed canal.
  2. breakage of endodontic instruments.
  3. discoloration of the crown.
  4. All of the above.

 

 

 

 

 

The answer is: D

 

 6- Bony lesions that may be associated with vertical root fracture include:

  1. a widened periodontal ligament space on one or both sides of the root.
  2. a halo-like lesion around the root apex extending to midroot.
  3. an angular periodontal defect extending apically from the crestal bone.
  4. All of the above.

 

 

 

 

 

 

The answer is: D

 

  7- Endodontic retreatment:

  1. is as technically challenging as original treatment.
  2. has a poorer prognosis than original treatment.
  3. is performed only on endodontic failures.
  4. has different objectives than primary treatment.

 

 

 

 

 

The answer is: B

 

 8- Clinically successful cases with radiographicaily unsatisfactory obturation:

  1. should always be retreated.
  2. should be retreated only if a new prosthetic restoration is planned.
  3. should be considered for retreatment or follow-up if a new prosthetic restoration is planned.
  4. should only be considered for follow-up if no new restoration is planned.

 

 

 

 

 

 

The answer is: C

 

 9- Which of the following aspects of the root canal filling is not a factor in determining whether an endodontic failure should be retreated or surgically treated:

  1. time since obturation.
  2. apical extension of filling material.
  3. density of filling material.
  4. type of filling material.

 

 

 

 

 

The answer is: A

 

 10- Removal of existing prosthetic restorations before retreatment:

  1. is always indicated.
  2. permits more radiographic information to be obtained.
  3. will not aid in revealing a vertical fracture.
  4. All of the above.

 

 

 

 

 

The answer is: B

  

 11- Overextended gutta-percha should be removed:

  1. by pulling it out in one piece.
  2. surgically.
  3. with rotary instruments.
  4. with solvents.

 

 

 

 

 

The answer is: A

 

 12- During retreatment (he coronal portion of gutta-percha should be:

  1. dissolved with solvents.
  2. drilled out.
  3. removed by heat.
  4. removed using ultrasonics.

 

 

 

 

 

The answer is: B

 

 13- Chloroform:

  1. is the most effective gutta-percha solvent.
  2. is prohibited for use in dentistry in most countries.
  3. has no adverse effects on clinicians.
  4. All of the above.

 

 

 

 

 

 

The answer is: A

 

 14- Which solvent, when heated, is as effective as chloroform:

  1. Xylene.
  2. Methyl chloroform.
  3. Halothane.
  4. Eucapil.

 

 

 

 

 

 

The answer is: D

 

 15- The technique of choice for removing poorly condensed guttapercha is:

  1. automated instrumentation.
  2. hand instrumentation.
  3. ultrasonic instrumentation.
  4. rotary instrumentation.

 

 

 

 

 

 

The answer is: B

 

 16- The Masscrann kit technique for removing solid objects:

  1. is not time consuming.
  2. is more successful in posterior teeth than in anterior ones.
  3. requires frequent radiograph monitoring.
  4. is better than the ultrasonic technique.

 

 

 

 

 

 

The answer is: C

 

17- In cases involving conventional endodontics, the most frequent cause of failure is:

  1. External root resorption
  2. Apical overfilling of the canal
  3. Inadequate filling of the accessory canals
  4. Incomplete obliteration of the main canal

 

 

 

 

 

 

The answer is: D