1. Temp at which tertiary amine activates benzoyl peroxide release free radicals60?C37?C25? C50?CQuestion 1 of 20 2. Purpose of reservior is toPrevent removal of molten metalHelp in removal of waxGives smooth polished surfacePrevent localised shrinkage porosityQuestion 2 of 20 3. Green shrinkage seen in :Gypsum Bonded investmentPhosphate Bonded InvestmentEthyl Silicate bonded investmentIt is seen in all types of investmentsQuestion 3 of 20 4. most common reason for incomplete casting when using a centrifugal casting machine islarge reservoirincreased porosity of the investmenthollow spacenarrow sprueQuestion 4 of 20 5. for best results when using an elastic impression material the prepared tooth should befree of surface moisturecovered thinly with a waer soluble lubricantcovered with a surface tension reducing agent or air driedvery dryQuestion 5 of 20 6. the working time of a phosphate investment mix can be increases by increasing themixing time and mixing efficiencyliquid /powder ratiotempperature of the mixall of the aboveQuestion 6 of 20 7. The main component of gypsum bonded investment which provides thermal expansion to compensate for alloy solidification shrinkage isRefractory fillerNone of the aboveBinderModifiers like magnesium oxide and sodium chlorideQuestion 7 of 20 8. One disadvantage of dental porcelain restorations is:brittlenesspoor estheticsexpansionradioactivityQuestion 8 of 20 9. Stain removing commercial denture cleanser usually containSodium hypochloritePotassium perborateSodium perborateSoda ashQuestion 9 of 20 10. Which of the following best describes "strain hardening" or "work hardening"?hardening (or deformation) of a metal at a very high temperaturesoftening a metal by controlled heating and coolingsoftening a metal at room temperaturehardening (or deformation) of a metal at room temperatureQuestion 10 of 20 11. gypsum investments disintegrates at700 degree C195 degree C200 degree C140 degree CQuestion 11 of 20 12. About pit and fissure sealant which is wrongIt is made of composite resin and sealant to prevent the cAriesIf in doubt whether the teeth is carious or not seal it with pit and fissure sealantIn sealed fissures prevent odonto pathogenic bacterial growthIt includes enamel bonding agent and resin without filler contentQuestion 12 of 20 13. the penetration of the fissure sealant into the fissuresis not influenced by the wettability of the enamelis independent of the chemical composition of the enamelmust occur before the polymerisation of the materialis the result of a chemical bond between the sealant and enamelQuestion 13 of 20 14. Bond strength required to counteract the effect of polymerization shrinkage in composite resins:7 MPa21 MPa17 MPa56 MPaQuestion 14 of 20 15. What chemical is added to prevent polymerization of polymethylmethacrylate during storage:Benzoyl peroxideCamphorquinoneTertiary aminesHydroquinoneQuestion 15 of 20 16. Primer which etches and primes dentin is known as:Self etching primerTwo step systemSelf etch adhesiveAuto etch adhesiveQuestion 16 of 20 17. when force is applied perpendicular to the metal surface,resultant deformation isshearing stresstensile stresstensile straincompressive strainQuestion 17 of 20 18. When electroplating an impression with copper the cathode isThe impression being electroplatedDistilled waterA copper paste or rodCopper sulphateQuestion 18 of 20 19. Which of the following property of amalgam is adversely affected by triturating with mechanical deviceGloss of final mixtureLess tarnish resistanceHardness of final mixtureWorking timeQuestion 19 of 20 20. type IV gold casting alloys are used for fabricating3/4 crownsremovable partial denture frameworksinlaysshort span bridgesQuestion 20 of 20 Loading...
