8801. What is the working time of zinc polyacrylate cement ?
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A. 4 Minutes

B. 3 Minutes

C. 2 Minutes

D. 1 Minutes

8803. Which of the following characterizes the silicate cement______________?
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A. Chemically attaches to the tooth structure

B. It produces thinnest film surface

C. It is pulpal irritant

D. It is highly cariogenic

8804. Mercury intoxication in dental office mainly results from____________?
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A. Direct contact with the mercury

B. None of the above

C. Inhalation of mercury vapours

D. Ingestion of mercury

8805. Age hardening is a process done at______________?
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A. Heating up to 200 450C for 15 30 min and quenching in water

B. Heating above 700C for 30 min and quenching in water

C. Heating at 700C for 1 hour and quenching in water

D. Heating at 700C for 10 15 min and quenching in water

8806. Mercury rich condition in a slow setting amalgam alloy system in a resoration in______________?
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A. Merginal damage

B. All of the above

C. Accelerated corrosion

D. Fracture of the restoration

8807. Which of the following are characteristic feature of high copper amalgam alloy ?
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A. Less marginal #

B. Low compressive strength

C. High creep

D. High marginal breakdown

8809. Increase in the residual mercury in silver amalgam filling can_____________?
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A. Tarnish and corrosion

B. Cause fracture of the filling

C. Increase the strength

D. Decrease condensation pressure

8810. The chief advantage of zinc phosphate cement is its___________?
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A. Good compressive strength

B. Film thickness

C. Lack of irritation

D. Low solubility

8811. Super abrasive is________________?
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A. Silicon arbide

B. Aluminum oxide

C. Sand

D. Diamond
8813. Pitting of direct filling old restoration usually results from_________________?
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A. Improper stepping of condenser point

B. Using contaminated gold foil

C. Poor finished preparation

D. Using small condenser point

8814. Which one of the following dental cements does not contain water as part of the composition of the liquid component ?
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A. Zinc silicophosphate cement

B. Zinc oxide equgenol cement

C. Zinc polycarboxylate cement

D. Zinc Phosphate cement

8815. The term trituration means____________?
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A. Lysing amalgam alloy

B. None of the above

C. Mixing of amalgam alloy and mercury

D. Removal of excess of mercury

8816. The highest mercury concentration in amalgam filling is found_____________?
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A. None of the above

B. In the deepest part of the restoration

C. At the margin of the restoration

D. In the centre of the restoration

8817. Condensation shrinkage of porcelain during firing depends on__________________?
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A. Rate of arriving at firing temperature

B. Uniformity of particle size

C. Type of investment used

D. Shape and size of particle
8818. Advantage of zinc phosphate over GIC is______________?
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A. Tensile strength

B. High compressive strength

C. Diametral strength

D. High modulus of elasticity
8821. Which of the following bur is used in the preparation of cavity restored with porcelain fused to metal ?
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A. Diamond bur

B. Diamond but for porcelain and carbide bur for metal

C. Carbide bur

D. Stainless steel bur

8823. The setting of zinc phosphate is accelerated by_____________?
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A. Adding a drop of oleic acid

B. Increasing mixing time

C. Adding a drop of water

D. Cooling the slab

8824. Ceramics fired to metals are processed by_______________?
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A. Machining

B. Slip casting

C. Heat pressing

D. Sintering
8825. Polycarboxylate cement is used for_____________?
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A. Leuting

B. Permanent restoration

C. Die material

D. Temporary restoration

8826. In a high copper amalgam the phase, which is eliminated is_______________?
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A. Gamma 2

B. Gamma 1 and 2

C. Gamma 1

D. No phase is eliminated

8827. High copper dental amalgams are superior to other amalgams because high copper dental amalgems______________?
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A. Are workable at lower Hg-alloy ratio

B. Have less marginal breakdown

C. Have less resistance to tarnish and corrosion

D. Have a higher ratio of tensile to compressive strength

8828. Adequate mixing of mercury is indicated by_______________?
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A. Dry Mix

B. Shiny Mix

C. Short Mixing Time

D. None of the above

8830. The major component of zinc phosphate cement is_____________?
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A. Zinc

B. Phosphoric acid

C. Zinc oxide

D. None of the above

8831. In method of firing: A shorter firing period at a higher temperature is considered better_______________?
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A. A large time period at a lower temperature is preferred

B. none of these

C. A short firing period at a very low temperature is preferred

D. A long firing period at a very high temperature is preferred
8833. Why GIC is best restorative material in children_____________?
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A. Good marginal integrity

B. High strength

C. It has less occlusal wear

D. It can bond enamel & dentin
8835. Moisture contamination of amalgam can lead to_____________?
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A. Delayed expansion

B. increased stresses

C. Shrinkage

D. Marginal breakdown

8836. Dynamic creep is the______________?
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A. Continuing alloying between silver-tin alloy and mercury during the life of restoration

B. Deformation of set amalgam during function

C. Spread of amalgam during packing

D. Process whereby alloy is wetted by murcury

8838. Discolouration of silver alloy is due to_____________?
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A. Dry corrosion

B. Tarnish and corrosion

C. Wet corrosion

D. Tarnish

8840. Greening occuring when porcelains are fired on silver free alloys may be attributed to________________?
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A. Silver ionization by porcelains with high oxygen potential

B. Vaporization of silver from the walls of contaminated furnaces

C. Surface diffusion of silver from the marginal metal

D. More rapid silver diffusion in sodium containing glass

8841. Chemical tempering in porcelains is done to interrupt crack propagation by______________?
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A. Dispersion of crystalline phase

B. Inducing residual compressive strength

C. All of the above

D. Transformation toughening

8842. High strength amalgam is achieved by_____________?
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A. Maximum matrix and minimum alloy phase

B. Minimum matrix and maximum alloy phase

C. Minimum alloy phase

D. Maximum matrix phase

8844. Porosity in porcelain can be prevented by_______________?
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A. Rapidity of firing

B. All of the above

C. High firing temperature

D. Thoroughness of condensation
8848. All of the following is used as accelerator in zinc oxide eugenol cement except_____________?
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A. Acetic acid

B. Calcium chloride

C. Zinc acetate dehydrate

D. Bromoglycerine
8849. The maximum shrinkage during firing proces in ceramic occurs in__________________?
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A. Low Bisque stage

B. High Bisque stage

C. Fusion stage

D. Medium Bisque stage