831. The high initial solubility of silicate cements is attributed to the?
A. acid-base nature of the setting reaction
B. rather long time required for the setting reaction to go to completion –
C. low coefficient of thermal expansion of the cemen
D. high water content of the cement liquid
832. During the trial packing of resin into a mold, the excess which flows into the land surrounding the mold space. is termed?
A. sprinkle
B. sheet
C. rosin
D. trim
E. flash
833. An alloy in which the atoms of two metals intermingle randomly in a common space lattice, and the metals are soluble in each other in the solid state, is termed?
A. intermetallic compound
B. eutectic alloy
C. solid solution
D. peritectic alloy
834. The primary reason why conventional porcelain alone is not used as a crown and bridge restorativematerial, is its?
A.microleakage
B. lack of strength
C. complicated fabrication technique
D. extreme hardness
E. lack of ductility
835. Sand is used for the polishing of?
A. noble metal alloys
B. amalgam restorations
C. resin dentures
D. base metal alloys
836. Strain hardening of a metal would result in an increase in its?
A. elastic modulus
B. ductility
C. resistanceto corrosion
D. strength
837. Fillers are added in composite resins to?
A. inhibit deformation of the matrix
B. reduce the coefficient of thermal expansion of the resin matrix
C. both of the above
D. none of the above
838. The creep rate of an amalgam restoration decreases when the?
A. mix is over triturated
B. time lag between trituration and condensation is more
C. mercury content of the mix is increased
D. mix is slightly undertriturated
E. condensation pressure is increased
839. Which of the following statements is not true regarding addition polymerization reaction?
A. There is no change in the composition
B. By products are formed
C. The reaction is exothermic
D. The reaction can be activated by UV light
E. None of the above
840. Which of the following resins are bio-degradable?
A. Cyanoacrylates
B. Polyurethanes
C. Polycarbonates
D. Polystyrenes
E. Epoxy resins