1. Loss of colour stability in self polymerizing resins is due to degradation of:Benzoyl peroxide initiatorHydroquinonePolymethyl methacrylateTertiary amineQuestion 1 of 20 2. carnauba wax is added to basic paraffin wax todecrease flow at mouth tempimprove the smoothness in moldingrender it resistant to cracking and flakingensure uniformity of batchesQuestion 2 of 20 3. the penetration of the fissure sealant into the fissuresis not influenced by the wettability of the enamelis the result of a chemical bond between the sealant and enamelmust occur before the polymerisation of the materialis independent of the chemical composition of the enamelQuestion 3 of 20 4. Must commonly used coupling agent of composites:-ZirconateSilicatesTitanatesOrganosilanesQuestion 4 of 20 5. When electroplating an impression with copper the cathode isA copper paste or rodCopper sulphateDistilled waterThe impression being electroplatedQuestion 5 of 20 6. the main advantage of a natural glaze rather than an applied glaze is that the natural glazerequires a lower firing temperatureis easier to achieveis more permanentoffers best estheticsQuestion 6 of 20 7. There are four types of gypsum products approved for use in dentistry. Which of the following types is used rarely today?Type IIType IType IVType IIIQuestion 7 of 20 8. During polymerisation from monomer to polymerdensity changes from 0.94 to 1.19 and volume shrinkage 7%density changes from 1.19 to 0.94 and volume shrinkage 7%density changes from 1.19 to 0.94 and volume shrinkage 21%density changes from 0.94 to 1.19 and volume shrinkage 21%Question 8 of 20 9. main advantage of zinc phosphate over GIC ismore biocompatibilityincrease modulus of elasticityincreased tensile strengthincrease compressive strengthQuestion 9 of 20 10. Which of the following best describes "strain hardening" or "work hardening"?softening a metal at room temperaturehardening (or deformation) of a metal at a very high temperaturehardening (or deformation) of a metal at room temperaturesoftening a metal by controlled heating and coolingQuestion 10 of 20 11. Polishing agent which is known as whitening agentNone of the aboveChromium oxideRougeIron oxideQuestion 11 of 20 12. Which of the following investment exhibit green shrinkageGypsum bondedPhosphate bondedAll of the aboveSilica bondedQuestion 12 of 20 13. Brush heap structure is seen in:PolyethersAddition siliconesImpression compoundAlginateQuestion 13 of 20 14. Any marked distortion of the casting is related toSuck back porosityLocalised shrinkageImproper temperature controlDistortion of the wax patternQuestion 14 of 20 15. strain hardening of a metal decreases itsproportional limitsurface hardnessstrengthresistance to corrosionQuestion 15 of 20 16. the prinicipal factor in minimising the firing shrinkage of porcelain is thefusion temperatureratio of flux to feldsparthoroughness of condensationuniformity of particle sizeQuestion 16 of 20 17. Phosphate bonded investment is made carbon free:For easier divesting of investmenTo prevent brittleness of alloyTo prevent staining of ceramicTo produce smooth castingQuestion 17 of 20 18. Which of the following is a solid solution?silver palladiumcobalt chromiumgallium silver alloyamalgamQuestion 18 of 20 19. of the following, most kind to the pulp issilicate cementsGICzinc phosphatepolycarboxylateQuestion 19 of 20 20. Fins and spines in casting are caused by:Prolonged heatingIncreased casting pressureWater film presentRapid heating of investmentQuestion 20 of 20 Loading...
