1. Most recent type of denture adhesive isSalts of gontrezCellulose based saltsAcrylic adhesivesNatural gumsQuestion 1 of 20 2. Palladium and platinum are added to base metal alloys to:Act as scavengerAs grain refinersReduce brittlenessImpart colorQuestion 2 of 20 3. Which impression material is most difficult to remove without fracturing teeth of a stone model?PolysulphideCondensation siliconePolyetherAddition SiliconeQuestion 3 of 20 4. Hysteresis, the phenomenon of sol-gel conversion of a reversible hydrocolloid ,is dependent uponTemperatureChemical reaction of constituentsWater contentAddition of modifiersQuestion 4 of 20 5. carnauba wax is added to basic paraffin wax toimprove the smoothness in moldingrender it resistant to cracking and flakingdecrease flow at mouth tempensure uniformity of batchesQuestion 5 of 20 6. which of the following is not a nobel metalosmiumrutheniumsilvergoldQuestion 6 of 20 7. gold alloys used for the fabrication of saddle bars and clasps aretype IItype IIItype Itype IVQuestion 7 of 20 8. Cerrobend alloy islow fusing material for removing memory patternshigh fusing metal for positioning or shielding stenthigh fusing metal for removing memory patternslow fusing metal for positioning or shielding stentQuestion 8 of 20 9. for best results when using an elastic impression material the prepared tooth should becovered with a surface tension reducing agent or air driedvery drycovered thinly with a waer soluble lubricantfree of surface moistureQuestion 9 of 20 10. The main component of gypsum bonded investment which provides thermal expansion to compensate for alloy solidification shrinkage isBinderRefractory fillerNone of the aboveModifiers like magnesium oxide and sodium chlorideQuestion 10 of 20 11. Suck back porosity is caused byImproper removal of gasAttaching sprue in proximal surfacesImproper venting of waxHot metal impinging on the mold surface to cause a hot spotQuestion 11 of 20 12. Purpose of reservior is toPrevent localised shrinkage porosityPrevent removal of molten metalGives smooth polished surfaceHelp in removal of waxQuestion 12 of 20 13. in processing an acrylic denture in a water bath a proper heating cycle is desired because of the possibility ofwarpagevolumetric expansion of the denture causing an open biteshrinkage of the dentureporosity due to boiling of the monomerQuestion 13 of 20 14. In mixing dental stone, why should the powder be sprinkled onto the water in the bowl?the addition of powder prevents the mix from becoming exothermicthe powder is added to the water to avoid using more than one bowlthis process results in better powder mixing and reduced chance for air bubblesthis is not recommended; the water should be added to the powderQuestion 14 of 20 15. Fins and spines in casting are caused by:Increased casting pressureRapid heating of investmentProlonged heatingWater film presentQuestion 15 of 20 16. Maximum shrinkage occurs in which stage:Low bisqueHigh bisqueAll stages show equal shrinkageMedium bisqueQuestion 16 of 20 17. Beta hemihydrate is calcinated byDehydrated in a boiling solution of 30% calcium chlorideUnder steam pressure in autoclaveIn presence of airIn absence of airQuestion 17 of 20 18. Which of the following property of amalgam is adversely affected by triturating with mechanical deviceHardness of final mixtureLess tarnish resistanceWorking timeGloss of final mixtureQuestion 18 of 20 19. What is the effect of addition of an accelerator or a retarder to a gypsum castThe compressive strength may increase or decrease depending upon the amount of the accelerator/retarder addedNo relation to compressive strengthThe compressive strength increasesThe compressive strength decreasesQuestion 19 of 20 20. Which of the following cannot be used for debridement of zirconia implant surfaceGold tip instrumentTitanium coated instrumentStainless steel instrumentHi grade plastic instrumentQuestion 20 of 20 Loading...
