991. Oil of clove contains?
A. 100 % eugenol
B.70-85 % eugenol
C.50-60 % eugenol
D.15-25% eugenol

992. Silver in the dental amalgam alloys?
A. decreases ductility
B.decreases the setting time
C.minimizes the formation of oxides
D.increases plasticity

993. The Vickers hardness number of a tempered steel bur is 800, whereas that of a tungsten carbide bur is?
A.less than 1000

994. Acid etching procedures with a resin system do not help in?
A. preventing thermal exchange
B.retaining the resin
C.providing a clean tooth surface for the resin
D. reducing microleakage

995. The greatest potential for marginal leakage related to temperature change occurs in?
A. zinc phosphate cement
B.amalgam alloy
C.direct Idling gold
D. composite resin
E.unfilled resin

996. Porosities that may occur during the processing of a denture will result in?
A. difficulty in proper cleaning of the denture
B.increased warpage of the denture
C.the denture being unsightly
D.weakening of the denture
E.all of the above

997. The greatest stress to which a structure can be subjected and return to its original dimensions when the forces are released is the?
A. modulus of elasticity
B.elastic limit
D.tensile strength

998. When curing a denture base, if insufficient pressure is used while packing, porosity will be seen?
A. at the denture periphery
B.in the frenum areas
C.in the thickest portion of the denture
D.uniformly distributed throughout the denture base
E.at the junction of the teeth and acrylic base

999. The weakest phase of set amalgam is?
A. gamma

1000. Methyl methacrylate?
A.does not react with fully polymerized acrylic resin
B.is a poor organic solvent
C.has a boiling point below that of water
D.is an opaque ,dirty, white colored liquid
E.none of the above