dental materials Mcqs
552. Which of the following cements is most irritant to pulpal tissues ?
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A. Polycarboxylate

B. Zinc phosphate

C. Silicate

D. Glass ionomer

553. Compare to conventional amalgams, spherical amalgams_______________?
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A. Have longer setting times

B. Require heavy compection forces

C. None of the above

D. Require more mercury

554. Plaster of paris is mixed in________________?
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A. Plastic bowl

B. Glass bowl

C. Rubber bowl

D. Metal bowl

556. Cavo surface angle for amalgam resoration is butt joint as____________?
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A. Decreased compressive, increased strength

B. Decreased compressive, decrease tensile strength

C. It increases compresssive and tensile strengths

D. Increased compressive, increased tensile strength

560. Creep value of which of the following is the highest ?
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A. Creep value of all the above mentioned alloys is same

B. Low copper amalgam alloy

C. Single composition alloys

D. Admix alloy

561. Advantage of minimum mercury technique or Eames technique is all Except________________?
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A. Needs no squeezing of excess mercury

B. High strength

C. Sets quickly

D. Greater plasticity and adapts well to cavity walls
562. For porcelain fused to metal crown, the porcelain should have ______________?
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A. Linear coefficient of thermal expansion less than that of metal

B. High fusion temperature

C. High fusion expansion

D. Linear coefficient of thermal expansion more than that of metal

564. Chronic mercury toxicity results from_____________?
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A. Mercury vapour

B. Ingestion while removing old amalgam

C. All of the above

D. Skin contact

565. Eugenol may be replaced in the zinc oxide eugenol cement by______________?
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A. Phosphoric acid

B. Ortho-ethoxy acid

C. Acetic acid

D. Alginic acid

566. The pure form of gold used in dentistry is known as___________________?
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A. Class I casting gold

B. Class IV casting gold

C. Cohesive gold

D. Non cohesive gold

568. The dental amalgam is most resistant to________________?
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A. Shear stress

B. Tensile stress

C. Compressive stress

D. Impact stress

569. Coefficient of thermal expansion of metal-ceramic alloys is________________?
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A. Same as porcelain

B. More than porcelain

C. Less than porcelain

D. More than or equal to porcelain but not less
570. The effect of trituration on strength in an amalgam restoration depends on______________?
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A. All of the above

B. Amalgam alloy

C. Speed of amalgamator

D. Trituration time

572. The ideal temperature of water bath for softening fluid wax is about________________?
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A. 51 to 54 degree C

B. 70 to 75 degree F

C. 51 to 54 degree F

D. 70 to 75 degree C

574. Which is true regarding lathe cut silver alloy_______________?
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A. Requires least amount of mercury

B. Achieves lowest compressive strength at 1 hr.

C. Has tensile strength both at 15 min & 7 days comparable to high copper unicompositional alloy

D. Has low creep

575. Pyroplastic flow of porcelain is due to___________________?
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A. High temperature during glazing

B. Improper condensation

C. High firing temperature

D. Low temperature during glazing

576. Secondary caries is least likely seen with_______________?
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A. Polycarboxylate

B. Silicate cement

C. GIC

D. Zinc phosphate

577. All of the following are true for traditional solution liner, except_________________?
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A. It is not necessary in moderately deep cavities under glass ionomer restoration

B. Do not provide thermal or electric insulation

C. Protect the pulp from reaction products leaching out of restoration

D. Have Film thickness of 1 50 microns
580. Fluoride rich materials include ?
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A. Silicate cement

B. Polycarboxylate cement

C. Glass ionomer cement

D. All of the above
581. Electrolyte used for plating copper dies is________________?
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A. Ionic copper

B. Silver cyanide

C. Acidic copper sulphate

D. Copper cyanide

582. All of the following is used as accelerator in zinc oxide eugenol cement except_______________?
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A. Bromoglycerine

B. Zinc acetate dehydrate

C. Acetic acid

D. Calcium chloride

584. The cement Which is least soluble in oral cavity______________?
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A. Glass ionomer

B. Silico-Phosphate cement

C. Resin cement

D. Polycarboxylate cement

585. Setting time of Amalgam is best controlled by _______________?
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A. Altering Hg-Alloy ratio

B. Trituration time

C. Using spherical particles

D. Lathe cut alloy

586. In non-eugenol pastes the constituents are mixed in______________?
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A. None of the above

B. Ethyl alcohol

C. Phosphoric Acid

D. Benzoic acid
587. Which of the following statements about high copper silver alloy compared to conventional alloy is not true ?
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A. Its edge strength is greater

B. It has poor tarnish and corrosion resistance

C. It has increased tensile and compressive strength

D. Mercury content in the final restoration is less

588. Which one of the following is not an objective of trituration ?
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A. Keep the amount of gamma-1 or gamma-2 matrix crystals to maximum

B. Achieve a workable mass of amalgam in minimum time

C. Pulverize pelletes into particles to aid in attack by mercury

D. Remove oxides from powder particle surface

589. Porcelain is best fired__________________?
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A. Under air compression

B. In open air

C. When several layer are fired simultaneously

D. Under minimum pressure

590. Crocus cloth is________________?
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A. Rouge

B. Emery

C. Pumice

D. Garnet

591. The cohesive gold used as bulk filler is_____________?
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A. Spherical gold

B. Electra alloy

C. Gold foll

D. Mat gold
593. Which of the following acts as accelerator in Zinc oxide eugenol______________?
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A. Zn(OH)2 + ZnO

B. ZnCl2 + ZnSO2

C. Eugenol + ZnO

D. ZnCl2 + Eugenol

594. Ethoxy benzoic acid increases the strength and solubility of the cement______________?
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A. Silicate cement

B. Zinc phosphate cement

C. Zinc oxide eugenol

D. Polycarboxylate cement

595. Which cement base has the highest modulus of elasticity ?
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A. Glass inomer cement

B. Zinc polycarboxylate

C. Polymer reinforced ZOE cement

D. Zinc phosphate
596. Frozen slab technique is applicable to_____________?
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A. Zinc oxide Eugenol cement

B. Glass Ionomer cement

C. Zinc phosphate cement

D. Resin cement

599. Machineable glass ceramic is________________?
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A. Infusium

B. Decor MGC

C. Cerestore

D. Leucite