1. After mixing powder and liquid in case of alginate impression material, gelation will occur in what time (at room temperature)?3-4 minutes1-2 minutes6-7 minutes10-12 minutesQuestion 1 of 20 2. Liquid which shows thickening on increasing strain is calledThixotropicPseudoplasticNewtonianDilatantQuestion 2 of 20 3. nickel in high percentages in noble metal dental casting alloysdecreases strengthincreases ductilitydecreases tarnish resistanceall of the aboveQuestion 3 of 20 4. Must commonly used coupling agent of composites:-SilicatesTitanatesZirconateOrganosilanesQuestion 4 of 20 5. Following is added to zinc polycarboxylate to improve its manageability:Strontium fluorideAluminium oxideMagnesium oxideStannous fluorideQuestion 5 of 20 6. the property of amalgam that makes it undesirable to bevel occlusal margins of an amalgam cavity preparation is itsductilitymalleabilitybrittlenessflowQuestion 6 of 20 7. For obtaining harder dies to be used for making wax patterns, all of the following can be done exceptUse an epoxy resin based dieAddition of die hardener to gypsumSilver plating of dieGold plating of dieQuestion 7 of 20 8. Pyroplastic flow in dental porcelainIs not an important considerationShould optimally be highIs determined by potash formIs decreased with a low soda/potash ratioQuestion 8 of 20 9. within practical limits when the water/powder ratio is increased beyond the recommended amount in mixing plaster thecompressive strength is decreasedsetting expansion is decreasedall of the abovesetting time is increasedQuestion 9 of 20 10. diamond particle size of 125-150 um is catagorised asextrafinefinemediumcoarseQuestion 10 of 20 11. oxides of all of the following elements in noble metal alloys help in bonding to porcelain exceptindiumtinironnickelQuestion 11 of 20 12. which orthodontic wire shows shape memoryCo-CrTMAa-TiNiTiQuestion 12 of 20 13. Which property of composites is most affected by the size and number of fillers:Polymerization shrinkageThermal contractionThermal expansionWater sorptionQuestion 13 of 20 14. test used to check setting time of impression material isrockwell testcold bend testvicat testvickers testQuestion 14 of 20 15. the porcelain constituent that fuses at firing temperature and forms a matrix iskaolinfeldsparaluminium oxidequartzQuestion 15 of 20 16. All of the following metals are considered to be base metals EXCEPT one.Which one is the EXCEPTIONchromiumsilvernickelcobaltQuestion 16 of 20 17. role if indium in amalgam isto reduce release of mercury during amalgam polishingto reduce elease of mercury during masticationto reduce formation of gamma 2 phaseto reduce formation of gamma phaseQuestion 17 of 20 18. Best cementing medium for self retained all ceramic crown isChemical cure resinDual cure resinGICRMGICQuestion 18 of 20 19. tartaric acid in GIC is added toincrease working timereduce viscositymodify handling propertiesincrease flow of materialQuestion 19 of 20 20. In mixing dental stone, why should the powder be sprinkled onto the water in the bowl?this is not recommended; the water should be added to the powderthe addition of powder prevents the mix from becoming exothermicthis process results in better powder mixing and reduced chance for air bubblesthe powder is added to the water to avoid using more than one bowlQuestion 20 of 20 Loading...
