Feb 2012 Conservative Dentistry and Endodontics Past Questions

FEB 2012   [LA 672]                                                                                  Sub.  Code: 4164
FOURTH B.D.S DEGREE EXAMINATION
PAPER IV CONSERVATIVE DENTISTRY AND ENDODONTICS
Q .P .Code: 544164

Time: Three hours                                                        Maximum: 70 Marks
Answer ALL questions in the same order Draw Suitable diagrams wherever necessary
I.  Elaborate on:                                                                           
(2×10=20)

1. Discuss in detail the materials and various steps involved in placing a composite resin restoration for a mesio – incisally fractured upper central incisor.

2. Define Working Length. Write in detail one method of working length determination. Discuss about  Stepback method of preparation of root canal.
II. Write notes on:                                                                       
(10×5=50)
1. Attrition, Abrasion and Erosion
2. Inlay wax pattern
3. Instrument grasps
4. Hypersensitivity
5. Shade matching for ceramics
6. High copper amalgam
7. Culture methods and reversal
8. Endosonics
9. Rationale of endodontic treatment
10. Post endodontic restoration
*******

Fracture of RCT treated tooth

# Which of the following accounts for why endodontically treated posterior teeth are more susceptible to fracture than untreated ones?
A. Loss of moisture
B. Damaged coronal structure
C. Plastic deformation of the dentin
D. Loss of pulpal vitality

The correct answer is B. DAMAGED CORONAL STRUCTURE

Endodontically treated teeth have a decreased amount of coronal dentin due to the access preparation necessary for root canal treatment.

Loss of coronal dentin alters the internal architecture of the tooth, changing the dispersement of forces in the tooth.

The change to the internal architecture put the tooth at higher risk for fracture.

Dental treatment - Endodontic perforation

# Which of the following locations would a perforation demonstrate the BEST prognosis?
A. Floor of pulp chamber
B. Coronal 1/3 of root
C. Middle 1/3 of root
D. Apical 1/3 of root

The correct answer is D. Apical third of root.


Apical perforations occur through the apical foramen or the body of the root to form  a new canal.

The more apical the perforation, the more favorable the prognosis for the tooth. (except for the coronal perforations)

Least reliable sign of pulpal disease in primary teeth:

Q. Which of the following is the least reliable sign of pulpal disease in primary teeth?
 A. Electronic pulp test
B. Spontaneous pain
C. Internal resorption
D. Furcal radiolucency
E. Swelling

The correct Answer is A. Electronic pulp test

Electronic pulp testing is very unreliable in primary teeth because the A fibers that are more easily stimulated by electricity appear late in pulpal maturity.

The accuracy of the pulp testing may also be affected by the patient's ability to describe their response to the stimuli, to which, pediatric patients are typically not as able to describe their experiences in a clinically relevant way.