1. Which of the following is known as smart ceramic:ZirconiaFeldspathic porcelainBioceramicnone of the above 2. Constituent of bioactive glass:ZirconiaCalcium carbonateSilicaAlumina 3. which cement has the highest modulus of elasticityzinc phosphatezinc polyreinforced ZOEzinc polycaroxylateglass ionomer cement 4. best cement for cementation of orthodontic molar bandszinc phosphatesilicatesilicophosphateGIC 5. highest water solubility is seen inzinc phosphatezinc oxide eugenolzinc silicophosphatezinc polycarboxylate 6. Least soluble cement in water:Zinc phosphateGICZinc oxide eugenolSilicate 7. Which of the following will produce the most rigid restoration for framework of same dimensionWrought alloyPalladium alloysCobalt chrome alloysPartial denture casting gold in hardened condition 8. Which of the following property of amalgam is adversely affected by triturating with mechanical deviceWorking timeHardness of final mixtureGloss of final mixtureLess tarnish resistance 9. all of the following processes can be performed at room temp exceptwork hardeningforgingcold workingstrain hardening 10. an advantage of rubber base impression material over reversible hydrocolloid material is that rubber base impression materialwill displace soft tissuerequires less armamentariumis significantly more accurateis more accurate if saliva mucus or blood is present 11. By product of setting reaction of condensation silicon:WaterHydrogenEthyl alcoholAcetone 12. in processing an acrylic denture in a water bath a proper heating cycle is desired because of the possibility ofwarpageshrinkage of the dentureporosity due to boiling of the monomervolumetric expansion of the denture causing an open bite 13. Clinical appearance of GIC is dictated byViscosity of liquidAcid content of liquidChemical composition of cementParticle size of powder 14. test used to check setting time of impression material isvicat testvickers testrockwell testcold bend test 15. for best results when using an elastic impression material the prepared tooth should bevery dryfree of surface moisturecovered thinly with a waer soluble lubricantcovered with a surface tension reducing agent or air dried 16. Nodule on the intaglio surface of a casting can be prevented byUse of a vibrator during investing of the wax patternUse of die spacerWet the wax with water before investingSpraying a surfactant on the wax pattern before investing 17. 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 die 18. titanium casting is doneunder vaccum in argon atmosphereunder air pressure in nitrogen atmospherein specifically fabricated aluminium vanadium cruciblesusing cad-cam technique 19. There are four types of gypsum products approved for use in dentistry. Which of the following types is used rarely today?Type IType IIType IIIType IV 20. gold alloys used for the fabrication of saddle bars and clasps aretype Itype IItype IIItype IV 21. Inlay wax suitable for making indirect pattern isType IType IIType IIIAny of the above 22. Ceramic is known for which property:TranslucencyOpaqueTransparencyColour 23. Principle purpose of annealing isTo remove the absorbed gasTo make the gold cohesiveTo eliminate strain hardeningTo change metal metallographically 24. role if indium in amalgam isto reduce elease of mercury during masticationto reduce release of mercury during amalgam polishingto reduce formation of gamma phaseto reduce formation of gamma 2 phase 25. Phosphate bonded investment is made carbon free:To prevent brittleness of alloyTo produce smooth castingTo prevent staining of ceramicFor easier divesting of investmen 26. the primary purpose of rinsing a set impression with a watery mix of dental stoneto increase the gel strengthto prevent further gelationto retard shrinkage due to syneresisto remove residual saliva from the surface of impression 27. which orthodontic wire shows shape memoryTMANiTiCo-Cra-Ti 28. high copper amalgams are superior to low copper amalgams because ofthey have high ratio of compressive to tensile or tensile to compressive strengthare workable at low mercury alloy ratiosshows less marginal fracturethey corrode in oral cavity 29. Casting shrinkage in a type 2 gypsum investment is counteracted by:Thermal expansion of the investmentSetting expansion of investmentHygroscopic setting expansion of investmentIncreasing the thickness of casting ring 30. ductility meansthe metal can be transformed into sheetspercentage elongationsubjecting a cylindrical specimen to a compressive loadincreases with rise in temperature 31. What is the effect of addition of an accelerator or a retarder to a gypsum castThe compressive strength increasesThe compressive strength decreasesThe compressive strength may increase or decrease depending upon the amount of the accelerator/retarder addedNo relation to compressive strength 32. exposure of a stone cast to tap water should be minimised becausethe cast will be weakenederoding of the cast will resultdimensional achange will occur in th ecastthe surface of the cast will acquire a chalky appearance 33. 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 exothermicthis is not recommended; the water should be added to the powderthis process results in better powder mixing and reduced chance for air bubblesthe powder is added to the water to avoid using more than one bowl 34. Transformation toughening of zirconia occurs due to change in phase from:Tetragonal to monoclinicCubic to tetragonalMonoclinic to tetragonalAustenitic to martensiti 35. Porcelain is strongest when in a state oftensiontorsionneutralitycompression 36. when force is applied perpendicular to the metal surface,resultant deformation istensile stresstensile straincompressive strainshearing stress 37. Strength of gypsum is measured asTensile strengthWet strengthGreen strengthCompressive strength 38. Shrinkage porosity is related toTemperatureMolten metalInlay waxSprue size 39. strain hardening of a metal decreases itssurface hardnessstrengthresistance to corrosionproportional limit 40. Any marked distortion of the casting is related toSuck back porosityLocalised shrinkageDistortion of the wax patternImproper temperature control 41. Following is added to zinc polycarboxylate to improve its manageability:Strontium fluorideMagnesium oxideStannous fluorideAluminium oxide 42. Young's modulus is defined as:Stress/strain below elastic limitStress/strain above elastic limitLimit where a material shows plastic defonnationArea under the stress strain curve till point of fracture 43. nickel is added to wrought gold alloys asstrengthenerscavengerage hardnerbalance of color 44. If gold content of the alloy decreases:Strength decreases, ductility increasesStrength increases, ductility decreasesBoth strength and ductility increasesBoth strength and ductility decreases 45. Effects associated with cold working i.e lowered ductility and distorted grains can be eliminated by process known asStrain hardeningAnnealingEutecticConcentricity 46. dental impression compound is characterised by having aspecific melting pointcrystalline atomic structurecross linkage reaction upon heatingrelatively low thermal conductivity 47. the heat treatment of soaking the alloy at a high temp to produce a solid solution followed by quenching is known assolution heat treatmentage hardeningliquid heat treatmentstrain hardening heat treatment 48. dental plaster powder and dental stone powder differ mainly insolubilityshelf lifechemical formulaparticle porosity 49. for a successful metal ceramic restoration both the metal and porcelain must have closely matchedsolidification shrinkagespecific gravitycoefficient of thermal expansioncompressive strength 50. Soldering flux is composed of all of the following EXCEPT one. Which one is the EXCEPTION?sodium pyroboratealumboraxsilica 51. Most common accelerator used in gypsum is:Sodium Chloride2% potassium sulphate1 % potassium sulphate2% sodium sulphate 52. what filler is used in impression compound "alginate"sodium bicarbonatediatomaceous earthcalcium alginatesodium phosphate 53. Stain removing commercial denture cleanser usually containSoda ashSodium perboratePotassium perborateSodium hypochlorite 54. the process of driving off the water of crystallisation of gypsum to manufacture powders of plaster and stone is calledsinteringcrazingcalciningfusing 55. which of the following will form a peritectic alloysilver and tinsilver and coppersilver and goldsilver and palladium 56. in Co-Cr alloys the constituent responsible for corrosion resistance issilvernickelchromiumcobalt 57. Principle hardener in gold alloy isSilverCopperZincPalladium 58. the antiflux used for gold solders issilicontitaniumcryolitegraphite 59. of the following, most kind to the pulp issilicate cementspolycarboxylatezinc phosphateGIC 60. the strength of gypsum bonded investment is dependednt uponsilica contentgypsum contentcopper contentcarbon content 61. Best material for casting base metal crown isSilica bondedHigh refractory silica bondedGypsum bondedPhosphate bonded 62. Pyroplastic flow in dental porcelainShould optimally be highIs determined by potash formIs not an important considerationIs decreased with a low soda/potash ratio 63. type IV gold casting alloys are used for fabricatingshort span bridgesremovable partial denture frameworksinlays3/4 crowns 64. the effectiveness of condensation and prevention of porcelain shrinkage is determined byshape and size of particlesthickness of platinum mixspeed of icrease of furnace heatuse of powder containing particles that are of same size 65. within practical limits when the water/powder ratio is increased beyond the recommended amount in mixing plaster thesetting time is increasedsetting expansion is decreasedcompressive strength is decreasedall of the above 66. Primer which etches and primes dentin is known as:Self etching primerSelf etch adhesiveTwo step systemAuto etch adhesive 67. Most recent type of denture adhesive isSalts of gontrezNatural gumsCellulose based saltsAcrylic adhesives 68. Bonding of porcelain veneer done by:RM-GICPolycarboxylateResin cementGIC 69. An impression is taken with addition silicone. What should be done before pouring the cast?Rinse with chloroformWait for sometime before pouringRinse with ketoneMix with some flavouring agent 70. When Alginate is mixed with tap water having high calcium sulfate and magnesium, what happensRetardation of setting reactionPermanent deformation of alginateAcceleration of setting reactionWeakened stone dies 71. Stiffness is related to?Resistance to plastic deformationResistance to elastic deformationDegree of elastic resistanceDegree of plastic resistance 72. role of flux in soldering isremoves oxideto preheatto melt the solderrestrict the flow of solder 73. direct wax pattern may distort due torelease of internal stressescomposition of waxmethoc of heating of waxthe placement of reservior 74. Which of the following statements is not true regarding glass ionomer cements?release fluoridegood thermal insulatorthermal expansion similar to toothhigh solubility after initial setting 75. The main component of gypsum bonded investment which provides thermal expansion to compensate for alloy solidification shrinkage isRefractory fillerBinderModifiers like magnesium oxide and sodium chlorideNone of the above 76. which zone of flame is used for melting alloysreducing zonecombustion zoneoxidising zonecentral zone 77. Addition of fillers in composite resins:Reduces strengthDecreases polymerization shrinkageIncreases wettabilityDecreases wear resistance 78. In relation to gypsum products, prolonged spatulation time will lead toReduced setting timeIncrease compressive strengthIncrease in hygroscopic expansionIncrease in hardness 79. tartaric acid in GIC is added toreduce viscosityincrease flow of materialincrease working timemodify handling properties 80. During final finishing of composite you find a void, what will you do:Re-etch and fill the compositeRemove entire composite and refill itLeave as it isFill with composite after etching, application of bonding agent 81. condensation shrinkage during porcelain firing is determined byrate of firinguniform distriution of particle sizetype of investment usedsize and shape of particle 82. Fins and spines in casting are caused by:Rapid heating of investmentProlonged heatingIncreased casting pressureWater film present 83. Continues use of vibrator during investing leads to?Random nodule formationSurface roughnessSurface irregularitiesDiscoloration 84. Hardening heat treatment for gold copper alloys involvesQuenching immediately after castingQuenching immediately after recrystallisationHeating to 350 degree C for 15-30 min followed by quenchingHeating to 700 degree C for 10 min followed by quenching 85. The process by which a casting is heated in a porcelain furnace to a temperature of 980"C to burn off any remaining impurities prior to adding porcelain is called:quenchingpicklingdegassinginvesting 86. Liquid which shows thickening on increasing strain is calledPseudoplasticThixotropicDilatantNewtonian 87. a thinner mix of gypsum bondeded investment will result inproduce a smoother castingdecrease setting expansionincreases setting expansionincreases thermal expansion 88. the function of monomer added to the heat curing resin polymer is primarily toproduce a plastic mass that can be packed into the moldstart the polymerisation reactionreduce the porosity and increase the strength of the applianceprovide adhesion of the resin base to the teeth 89. A system of manufacturing copings from blocks of pure titanium by machine duplication and spark erosion isProceraEmpressInceramCaptek 90. A base that is typically placed over a calcium hydroxide base (which has been placed over a pulp exposure); is known as:primary basesecondary basedirect baseindirect base 91. Fluoride flux used in soldering works by Preventing flow of solder to other areasPrevents formation of chromium oxide or dissolves already formed chromium oxideWeakens the solder jointForms a protective film during soldering 92. Polysulfide impression material should be:poured immediatelypoured within 15 minutespoured within 30 minutespoured within 1 hour 93. One disadvantage of dental porcelain restorations is:poor estheticsexpansionbrittlenessradioactivity 94. Which material has least shelf lifePolysulphidePolyetherCondensation siliconeAddition silicone 95. With which of the following impression materials is it advisable to wait 20 to 30 minutes before pouring of models for stress relaxation to occur?Polysulfidescondensation siliconespolyvinyl siloxanespolyethers 96. Which material is sensitive to Sulfur contamination from latex gloves:PolysulfideAddition siliconePolyetherAgar 97. Which property of composites is most affected by the size and number of fillers:Polymerization shrinkageThermal contractionThermal expansionWater sorption 98. When using which impression material can you delay pouring up of the model for up to one week?Polyetherpolysulfidereversible hydrocolloidpoly vinyl siloxane 99. Which impression material is most difficult to remove without fracturing teeth of a stone model?PolyetherAddition SiliconeCondensation siliconePolysulphide 100. Mercaptan are a component of:PolyetherPolysulphideAddition siliconeCondensation silicone Loading...