1121. Class IV cavity :

A. Occurs on the proximal surface of anterior teeth that does not involve the incisal edge
B. Occurs on the proximal surface of anterior teeth that does involve the incisal edge *
C. Occurs on the proximal surface that involves the incisal edge of posterior teeth
D. Occurs on the buccal surface of both anterior teeth and posterior teeth

1122. Finishing and polishing of amalgam made the restoration cause :

A. Expansion in stain and erosion obstruction *
B. Increase the marginal strength
C. Decrease in tarnish and corrosion resistance
D. Increased compressive strength

1123. A patient complains of sensitivity in a mandibular premolar. Five months ago, a well-condensed class V and amalgam restoration was placed in that tooth without any discomfort. for the first 4 months. Since then it has become increasingly sensitive .The problem is probably related to :

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

1124. For a class V cavity for amalgam :

A. Mesio-distal walls are parallel and occluso gingival walls converging
B. Mesio-distal walls diverging , occluso gingival walls converging
C. Mesio-distal walls diverging, occuso- gingival walls diverging *
D. Mesio-distal walls and occluso-gingival walls parallel

1125. Most chances of exposure are for which pulp born while cavity preparation :

A. Mesiobuccal and mesiolingual pulp horns of primary mandibular 2nd Molar
B. Mesiobuccal and monolingual pulp horns of deciduous mandibular Ist Molar *
C. Distobuccal and Distolingual pulp horns of deciduous mandibular 1st Molar
D. Mesiobuccal and mesiolingual pulp horns of deciduous maxillary 1st Molar

1126. After application of pit and fissure sealants, caries occur, may e , All are except :

A. Fracture of pit and fissure sealant
B. Leakage of pit and fissure sealant
C. Due to improper acid etching, leakage between sealant and tooth junction
D. No flouride present in pit and fissure sealant *

1127. For photo curing the composite resin, the light sources :

A. Is fiber optic
B. Operator needs no protection while in use
C. Should be held at a millimeter distance from restoration
D. A and C *

1128. When using the acid etch technique to restore a class IV situation, exposed dentin should first be covered with :

A. Cavity varnish
B. Phosphoric acid
C. ZOE cement
D. Calcium hydroxide liner *

1129. Threaded pins are used in large dental amalgam restorations to provide :

A. Resistance form
B. Retention form *
C. Much needed reinforcement to amalgam
D. Occlusal stops for opposing teeth

1130. On a carbide bur , a greater number of cutting blades result in :

A. Less proficient cutting and smoother surface *
B. More efficient cutting and smoother surface
C. Less efficient cutting and rougher surface
D. More efficient cutting and rougher surface