1111. Sterilization of hand piece will cause ?

A. Rust of hand piece
B. Turbine wear
C. Fibre loss *
D. Loss of torque

1112. Change in all the following affects the efficiency of bur except ?

A. Neck diameter
B. Shape and size *
C. Length and shape
D. Clearance angle

1113. In endodontic surgery, which of the following about chronic gut auteurs is not true :

A. It has inferior properties to simple gut sutures
B. It is coated with chromium trioxide
C. Compared to standard gut sutures, it is less biocompatible.
D. Its absorption is faster than the palin get sutures *

1114. The range of wave lenght of visible light curing system is :

A. 400-700 mm
B. 410-500 mm *
C. 365-400 mm
D. 700-900 mm

1115 In class II cavity preparation the axiopulpal line angle is rounded to ?

A. Prevent the fracture of enamel
B. Prevent the fracture of amalgam *
C. Prevent the fracture of gingival sheath
D. Prevent the fracture of dentin

1116. The thickness of a class II matrix should be :

A. 0.5 mm
B. 0.002 mm
C. 0.002 Inches *
D. 0.00002 inches

1117. The reason for sealing caries during cavity preparation is :

A. To reduce the need for direct pulp capping in the future.
B. Create an aseptic field in the event of pulp exposure.
C. The allow the formation of second Tory dentin before excavation *
D. To create a solid surface that will serve as the foundation for future restoration

1118. Ramesh a 40 year old patient experiences sensitivity in a mandibular 2nd premolar which has a well condensed class V dental amalgam filling done 5 months previously . There was no problem for the last 4 months. The most probable cause of increased sensitivity could be due to :

A. Margnal leakage
B. Tooth brush abrasion
C. Fractured restoration
D. Irreversible pulpal damage *

1119. The restorative material which shows chemical bonding to the tooth surface is :

A. Composite resins
B. Glass ionomer cements *
C. Unfilled resins
D. Zinc phosphate

1120. In the restoration of deep cavities with composite resins, the following precaution have to be takes to the protect the pulp:

A. Calcium hydroxide base *
B. Cavity varnish
C. Zinc oxide eugenol palliative base
D. No need for a base as they are non-irritant to the pulp