1131. Microbrasion involves the use of :

A. Sulphuric acid
B. Acetic acid
C. Phosphoric acid
D. Hydrochoric acid *

1132. Enamel etched by a tooth conditioner but not covered with a fissure sealant will :

A. Remineralize within a month
B. Remineralize within 3 months *
C. Absorb stain and discolor the tooth
D. Leave the tooth more susceptible to caries attack

1133. Over- trituration of silver alloy and mercury ?

A. Reduce contraction
B. Strengthens lathe-cut alloy more than spherical alloy amalgam, but weakens lathe-cut alloy *
C. Decrease creep
D. Gives a dull and crumbly amalgam mix

1134. Which of the following statements is true regarding lathe-cut silver alloy?

A. Requires least amount of mercury
B. Achieves lowest compressive strength at 1 hour *
C. Has tensile strenght , both at 15 minutes and > days is comparable to high copper
D. Has lower creep value

1135. Minimum depth of lesion to be visible on radiograph is ?

A. 40 um
B. 50 um
C. 100 um
D. 500 um *

1136. Which of the following material can be confused with caries ?

A. Amalgam
B. Gutta percha
C. Composite *
D. ZoE

1137. The optimum ratio of the lenght of the pin into amalgam to that of dentin should be :

A. 1:1 *
B. 2:1
C. 3:1
D. 4:1

1138. The cavosurface angle of amalgam cavity preparation should be :

A. Beveled
B. Rounded
C. Right angle *
D. None

1139. What is the disadvantage of using ” winged” rubber dam retainer ?

A. It doesn’t provide extra retention of rubber dam
B. It interference with the placement of matrix band *
C. They do not allow attachment of the dam to retainer
D. None of the above

1140. Diamond particle sizes of 125-150 mm is categorized as :

A. Fine
B. Coarse *
C. Very fine
D. Medium