1. Which impression material is radio opaque:Poly etherPolysulfideAddition siliconeCondensation silicone 2. The ratio of transverse contraction strain to longitudinal extension strain in the direction of stretching force is known asPoissons ratioCompressive stressTensile stressShear stress 3. Which investment shows high contraction due to loss of water and alcohol:Phosphate bonded investmentMg bondedSilicate bondedGypsum bonded 4. Green shrinkage seen in :Phosphate Bonded InvestmentEthyl Silicate bonded investmentGypsum Bonded investmentIt is seen in all types of investments 5. Not associated with corrosion products in metal alloysOxidesChloridesSulphidesCarbonates 6. Non eugenol pastes contain ____ instead of eugenol:Orthoethoxy benzoic acidZinc acetateZinc chloridePolyethylmethacrylate 7. Must commonly used coupling agent of composites:-OrganosilanesZirconateTitanatesSilicates 8. for zinc oxide eugenol all of the following are true exceptolive oil is used as plasticizeraddition of methyl methacrylate resin increases strengthaddition of EBA in concentration of 37-50 percent increases strengthresin decreses the brittleness of set cement 9. an amalgam is an alloyof two or more metalsone of whose consituent is silverof silver and tinone of those whose constituent is mercury 10. metal ceramic restorations may fail due to fracture of the ceramic material .this can be best avoided ifocclusal forces are minimalthe metal is not over 0.5 mm thickthe ceramic material is at least 1.5 mm thickthe casting is designed to reduce stress concentration in the ceramic material 11. the accuracy of the temperature of the casting furnace may be verified byobserving the color of the mold in shadowusing templates of chemicals that melt at a specific temperaturereading the pyrometerusing a thermometer 12. oxides of all of the following elements in noble metal alloys help in bonding to porcelain exceptnickelirontinindium 13. All of the following metals are considered to be base metals EXCEPT one.Which one is the EXCEPTIONnickelcobaltchromiumsilver 14. most common reason for incomplete casting when using a centrifugal casting machine isnarrow sprueincreased porosity of the investmentlarge reservoirhollow space 15. The dentist can best control the setting time of irreversible hydrocolloid impression material by altering theMixing timeWater temperatureWater powder ratioAmount of retarder added 16. in size the largest porosities in a casting are of which typemicroporositypin holesuck backgas inclusion 17. Which composite type is 70% to 77% percent filled by volume and has an average particle size ranging from 1 to 3 um.Microfillshybridsmicrohybridspackables 18. the restorative material having hardness nearest to that of enamel ismicrofilled composite resindirect filling goldsilicate cementamalgam 19. While shade matching; as the brightness becomes more intense, color appears to change. This effect is known asmetamerismMunsell effectBezold-Brucke effectFlouroscence 20. The phenomenom where porcelain appears different under varying light conditions isMetamerismTransmittanceOpacificationRegractive optics 21. bonding of GIC to tooth structure is brought about bymetal ionshydroxyl groupcarboxyl groupfine pumice 22. A very active metal which is gas at room temperature isMercuryGalliumHydrogenOxygen 23. the union of metal to porcelain fused restoration is bymechanically rough surfacetin and indium oxidesnickel and orcelaincobalt and porcelain 24. Which of the following is formed by spray atomization and chemical precipitation of molten goldMat goldGranular goldGold foilCrystalline gold 25. Cutting edge of surgical burs are made from martensite form rather than austenite form due to which of the following reasonMartensite form is hardMartensite form is corrosion resistantMartensite form is very brittleMartensite form has less strength 26. Type I GIC isLutingLiningRestorativeResin modified 27. Material added in In-Ceram:LuciteFeldsparAluminaKaolin 28. Cerrobend alloy islow fusing metal for positioning or shielding stentlow fusing material for removing memory patternshigh fusing metal for positioning or shielding stenthigh fusing metal for removing memory patterns 29. the working time of a phosphate investment mix can be increases by increasing theliquid /powder ratiotempperature of the mixmixing time and mixing efficiencyall of the above 30. the length of sprue formers depends primarily on thelength of the casting ringthickness of the wax patternthickness of sprue formerangle at which it is attached to the pattern 31. methyl methacrylate can be activated by all of the following exceptlead peroxidetertiary aminessulfuric acid derivativesheat 32. heat energy required for vaporisation of liquid after boilinglatent heat of sublimationlatent heat of fusionlatent heat of vaporisationmelting temperature 33. the ability of diresct filling gold to be welded together at room temperature is because of its malleability andlack of oxide surface coatinghigh thermal conductivityextreme softnesshigh degree of purity 34. Fluid wax impression techniques may use following waxes exceptKorecta waxKerr ivory inlay waxSticky waxApplegates fluid wax 35. the porcelain constituent that fuses at firing temperature and forms a matrix iskaolinquartzfeldsparaluminium oxide 36. Which of the following is true statements regarding the polishing of amalgam?it should be done about 10 minutes after placementocclusion should not be checked prior to polishingit prevents tarnishing of the restorationit should be done with a dry polishing powder 37. About pit and fissure sealant which is wrongIt is made of composite resin and sealant to prevent the cAriesIt includes enamel bonding agent and resin without filler contentIf in doubt whether the teeth is carious or not seal it with pit and fissure sealantIn sealed fissures prevent odonto pathogenic bacterial growth 38. the penetration of the fissure sealant into the fissuresis not influenced by the wettability of the enamelis independent of the chemical composition of the enamelis the result of a chemical bond between the sealant and enamelmust occur before the polymerisation of the material 39. the main advantage of a natural glaze rather than an applied glaze is that the natural glazeis more permanentis easier to achieveoffers best estheticsrequires a lower firing temperature 40. Polishing agent which is known as whitening agentIron oxideRougeChromium oxideNone of the above 41. porcelain are made opaque by the addition of oxides ofiron and aluminiumboron and magnesiumnickel and iridiumtitanium and tin 42. the primary oxygen scavenger in noble metal casting alloy isironzinccoppersilver 43. Use of type II ZOE cement:Intermediate restorationTemporary cementationTemporary restorationPermanent cementation 44. Asbestos is used as a lining in a casting ring toinsulate against thermal conductivityallow for expansion of the investment.prevent fracture of the investment during heating.facilitate removal of the investment after casting. 45. setting time of zinc phospahte cement is retarted byincreasing the rate of addition of powder to liquidincreasing the powder liquid ratiodiluting the liquid with a small amount of waterdecreasing the rate of addition of powder to liquid 46. Function of molybdenum in base metal alloys?Increases strengthDecreases strengthIncrease CTEDecrease corrosion resistance 47. nickel in high percentages in noble metal dental casting alloysincreases ductilitydecreases tarnish resistancedecreases strengthall of the above 48. Wettability can be increased by:Increase in surface areaIncrease in surface energyIncreasing the contact angleReducing the internal stresses 49. main advantage of zinc phosphate over GIC isincrease compressive strengthincrease modulus of elasticitymore biocompatibilityincreased tensile strength 50. In metal-ceramic restorations, failure or fracture usually occurs:in the porcelainat the porcelain-metal interfacein the metalNone of the above 51. Beta hemihydrate is calcinated byIn presence of airIn absence of airDehydrated in a boiling solution of 30% calcium chlorideUnder steam pressure in autoclave 52. Gutta percha, stearic acid and shellac are added to impression compound to:Improve workability & plasticityTo increase stifthess and hardness of the compoundTo improve softness at melting temperatureTo prevent leaching out ofthermolabile components 53. Enamel resin bond used forImprove mechanical bond of resinConsist of a highly filled liquid acrylic monomer mixture placed onto acid etched enamelCan be used for enamel as well as DentineIt has no role in preventing micro leakage 54. Suck back porosity is caused byImproper removal of gasImproper venting of waxAttaching sprue in proximal surfacesHot metal impinging on the mold surface to cause a hot spot 55. A thin application of cavity varnish over the cut surface of a prepared tooth just prior to the cementation of a crown or a bridge with zinc phosphate cement willimpede the seating of the restoration.insulate the tooth against thermal changeincrease the possibility of thermal sensitivity.reduce the possibility of irritation of the pulp 56. In hot and dry environment, alginate shrinks byImbibitionSyneresisHysteresisAccretion 57. hydrocolloid impression material may experience all of the following exceptimbibitionssyneresisrecrystallsationhysteresis 58. Correct property of the tilite alloy isIdeal for implantsComposition is nickel, chromium, molybdenum, titaniumBonding to porcelain is more as compare to noble metalCantilever up to 5 mm can be given 59. What chemical is added to prevent polymerization of polymethylmethacrylate during storage:HydroquinoneTertiary aminesBenzoyl peroxideCamphorquinone 60. Loss of colour stability in self polymerizing resins is due to degradation of:HydroquinoneTertiary aminePolymethyl methacrylateBenzoyl peroxide initiator 61. The relative amount of lightness or darkness in a color is referred to as:huechromavalueintensity 62. Lower density usually means?High strengthLow strengthLow melting temperatureLighter weight 63. maximum shrinkage of firing of ceramic occurs during which stagehigh bisquelow bisquemedium bisquenone of the above 64. Maximum shrinkage occurs in which stage:High bisqueLow bisqueMedium bisqueAll stages show equal shrinkage 65. Which of the following cannot be used for debridement of zirconia implant surfaceHi grade plastic instrumentTitanium coated instrumentGold tip instrumentStainless steel instrument 66. Etching of feldspathic ceramic:HF acidHCL35% Phosphoric acidHN03 67. Purpose of reservior is toHelp in removal of waxPrevent localised shrinkage porosityPrevent removal of molten metalGives smooth polished surface 68. Microwave polymerisation for Acrylic dentures uses:Heat ConductionHeat ConvectionMagnetic FieldRadiation 69. the activator for autopolymerising resin is likely to beheathydroquinonetertiary aminebenzoyl peroxide 70. According to the ADA classification for alloy systems used for metalceramic restorations, noble alloys:have a noble metal content of > 60%have a noble metal content of > 45%have a noble metal content of > 25%have a noble metal content of > 15% 71. the most important mechanical property involved when a base metal partial denture clasp is adjusted ishardnesselongationelastic imittensile strength 72. the difference between heat cured and cold cured acrylic resin is least significant with respect to the property ofhardnesstransverse strengthcolor stabilityinternal porosity 73. Which of the following best describes "strain hardening" or "work hardening"?hardening (or deformation) of a metal at room temperaturehardening (or deformation) of a metal at a very high temperaturesoftening a metal by controlled heating and coolingsoftening a metal at room temperature 74. Which of the following investment exhibit green shrinkageGypsum bondedPhosphate bondedSilica bondedAll of the above 75. Contact angle between liquid and adherend surface is 180 degree. This suggestsGood wettingPoor wettingCompletely non wettingnone of the above 76. which of the following is not a nobel metalgoldrutheniumsilverosmium 77. when selecting the color of cememt to use for cementing a porcelain jacket crown the powder being tested is best mixed withglycerine water solutioncement liquidalcoholonly water 78. All of the following statements are true regarding glass ionomer restorations,exceptglass ionomer is often the ideal material of choice for restoring root surface caries in patients with high caries activitythe best surface finish for a glass ionomer restoration is that obtained against a surface matrixglass ionomers are somewhat esthetic and polish much better than compositesglass ionomer adheres to mineralized tooth tissue 79. The aramid and ribbond fibers are used to strengthenGlass ionomerCeramicAcrylic resinPolyether material 80. Metal oxides are added to powder of porcelain forGive color, increase strengthGive color , decrease strengthDecrease strength; act as a refractory skeletonIncreased strength; act as a refractory skeleton 81. Which of the following cements provide maximum resistance to decalcification while placing bands on molarGICPolycarboxylateZinc phosphateSilicate 82. Which phase of the amalgam reaction is prone to corrosion in clinical restorations?Gammagamma-onegamma-twogamma-three 83. Which of the following is a solid solution?gallium silver alloyamalgamsilver palladiumcobalt chromium 84. the prinicipal factor in minimising the firing shrinkage of porcelain is thefusion temperatureratio of flux to feldsparuniformity of particle sizethoroughness of condensation 85. Stress is:Force applied perpendicular to the surfaceForce applied per unit areaAn internal force opposing an applied loadA deformation resulting from an applied load 86. Shade matching is done in what light condition:Fluorescent light at 6500KDay light at 6000KIncandescent light bulb at 2500KColour corrected fluorescent light at 5500K 87. the property of amalgam that makes it undesirable to bevel occlusal margins of an amalgam cavity preparation is itsflowductilitybrittlenessmalleability 88. diamond particle size of 125-150 um is catagorised asfinecoarseextrafinemedium 89. What distinguishes a base from a cement from a cavity liner?final application thicknessdegree of pulpal protectionbiocompatibility of materialdegree of hardness 90. in an alginate impression material trisodium phosphate is thefillerreactorretarderaccelerator 91. Which of the following is used for making blades and sharp surgical instruments:Ferrite steelmartensitic steelAustenitic steelnone of the above 92. a cermet is a combination offeldspar and quartzsilver amalgam powder and glass ionomer powderconventional and aluminous ceramic powdersthe powders of polycarboxylate and composite resin cements 93. self curing acrylics for tooth restorations are least compatible with which materialeugenolcopal varnishalcoholcalcium hydroxide 94. Pinhole porosities are related toEntrapement of gas during solidificationCasting investment junctionSprue casting dissociationDistortion of wax pattern 95. carnauba wax is added to basic paraffin wax toensure uniformity of batchesimprove the smoothness in moldingrender it resistant to cracking and flakingdecrease flow at mouth temp 96. the significance of free eugenol in root canal sealer cements is an increase indimensional stabilitycytotoxicitysetting timestrength 97. Modulus of elasticity/tensile strength of brittle materials is measured byDiametrical compresssion testCold bend test3-point bend testCharpy test 98. Low-fusing porcelain is usually used for the manufacture of:denture teethall ceramic crownsmetal-ceramic crownsall of the above 99. During polymerisation from monomer to polymerdensity changes from 1.19 to 0.94 and volume shrinkage 7%density changes from 0.94 to 1.19 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% 100. each crystal of the polycrystalline metal is termeddendritegrainbushseed Loading...