Biomaterial Test 0% 5 votes, 5 avg 0 You will have 60 minutes to complete all the questions. After the timer reaches 60 minutes, the exam will end and be saved automatically. Good luck! *Fingers crossed* The timer has been reached. The exam has now been terminated and saved. Biomaterial Test 1 / 60 The cracks formed on the ceramic during cooling because 😕 a. The inner layer cools more rapidly than the outer layer b. The outer layer cools more rapidly than the interior c. The cooling of the outer and the inner layer occurs at the same rate d. Due to external forces 2 / 60 Condensation of porcelain is done by all the methods except 😕 a. Vibration method b. Brush addition technique c. Ceramming method d. Spatulation method 3 / 60 The energy absorbed by a material when it is stressed to its proportional limit is 😕 a. Flexibility b. Resilience c. Toughness d. Impact strength 4 / 60 Which of the following properties are higher for microhybrid composites than for microfilled composites ? a. Water sorption b. Thermal expansion c. Polymerization shrinkage d. Modulus of elasticity 5 / 60 Gypsum investments should not be heated above 😕 a. 4500C b. 10000C c. 17000C d. 7000C 6 / 60 Which of these statements are correct in terms of preparing a correctly triturated mass of amalgam ? a. A correctly triturated mass is a smooth homogeneous, and dull. b. An overmixed mass is removed readily from the capsule but is soupy in appearance. c. An undertriturated mass is crumbly and dull. d. Dental amalgam is a mixture of silver alloys and mercury. 7 / 60 Proconditioning before GIC restoration is done in order to 😕 a. Remove smear layer b. Provide more strenght c. Facilitate mechanical bonding d. Create tags 8 / 60 One of the following statements which one is incorrect regarding addition silicones 😕 a. Dimensionally stable even after 1 week b. Can be used in automixing devices c. Undetectable distortion on removal d. No evolution of any byproduct under all circumstances 9 / 60 Once amalgamation has occurred, which of the following is true of mercury ? a. Has the toxic properties of unreacted mercury b. Composite restorative resins c. Can form at the surface of amalgam restorations if heated to 0° C d. Is combined primarily with silver 10 / 60 Distortion on removal from undercuts in addition silicones is very less due to 😕 a. Increased strain rate on unset material b. Shrinkage of material c. Stiffness of the material d. Lowest strain in compression 11 / 60 Main disadvantage of laminate technique of making impression is : ? a. Difficult to manipulate b. Bond between agar and alginate is not very strong c. Cost factor is high d. Maximum details are not produced 12 / 60 Proportional limit is defined as : a. The maximum force required to cause a structure to break b. A deformation resulting from an applied load c. The maximum stress that can be induced without permanent deformation d. The stress/strain ratio within the elastic limit in a structure 13 / 60 The constituent that acts as a binder in the investment is 😕 a. Gypsum b. Silica c. Water d. Quartz 14 / 60 Elgiloy arch wire is 😕 a. Optical fiber arch wire b. Gold alloy c. Cobalt-chromium-nickel alloy d. β-titanium arch wire 15 / 60 Materials having coefficient of thermal expansion close to the tooth structure 😕 a. Glass ionomer cement b. Amalgam c. Silicate cement d. Unfilled 16 / 60 Dental porcelains are manufactured by a process termed as 😕 a. Sintering b. Fusing c. Fritting d. Vulcanizing 17 / 60 Main disadvantage of denture base soft reliner is 😕 a. It has not to be changed over a period of time b. It can not lead to cleaned property c. It can be cleaned properly d. It can not lead to fungal growth 18 / 60 Porcelain denture teeth 😕 a. Have decreased abrasion resistance than dentin b. Are easy to grind and polish c. Have higher coefficient of thermal expansion than resin teeth d. Are more resistant of abrasion than gold 19 / 60 A full crown on a maxillary anterior tooth may be restored with which of the following restorative materials ? a. Gold alloys b. Amalgam c. Ceramic d. Composite resin 20 / 60 The appropriate proportion of polymer to monomer component of dental resin by volume is generally 😕 a. 1:3 b. 2:1 c. 3:1 d. 1:2 21 / 60 Nickel in base metal alloys increase its 😕 a. S Ductility b. Strength c. Modulus of elasticity d. Hardness and fusion temperature 22 / 60 Ideal metal used for electroplating polysulfide impression is 😕 a. Silver b. Copper c. Cobalt d. Nickel 23 / 60 Which of the following is used to alter contour of impression trays ? a. Beading wax b. Utility wax c. Carding wax d. Boxing wax 24 / 60 The byproduct in condensation silicones is 😕 a. Ethyl alcohol b. Methyl alcohol c. Propyl alcohol d. Butyl alcohol 25 / 60 Greening effect of porcelain is due to 😕 a. Silver b. Palladium c. Platinum d. Golde 26 / 60 Resistance of a liquid to motion is called 😕 a. Viscosity b. Springiness c. Creep d. Diffusion 27 / 60 The strain at which the plastic strain develops may be represented by 😕 a. Elastic limit, yield strength, proportional limit b. Yield strength, tensile strength, toughness c. Toughness, rigidity, resilience d. Elastic limit, modulus of elasticity, tensile strength 28 / 60 Which of the following statements apply to the packable composites ? a. Their depth of cure allows bulk polymerization, which has been shown to be clinically effective. b. Their wear rate is low (3.5 μm/year). Which is similar to that of amalgam. c. Radiopaque d. They are radiolucent. 29 / 60 Conventional dental amalgam alloy contains 😕 a. Silver, tin, palladium and zinc b. Silver, mercury, copper and zinc c. Silver, mercury, copper and mercury d. Silver, tin, copper and zinc 30 / 60 Bis-GMA is a reaction product of 😕 a. Bis-phenol-A and urethane dimethacrylate b. Urethane dimethacrylate and glycidyl c. Bis-phenol-A and glycidyl methacrylate d. Bis-phenol-A and methyl methacrylate 31 / 60 A portion of a posterior tooth that is subject to high biting forces would likely be restored with which of the following ? a. Glass ionomer b. Amalgam c. Composite resin d. Acrylic resin 32 / 60 The main advantage of composites compared to silicates cement is 😕 a. Color matching with the tooth structure is excellent b. Coefficient of thermal expansion close to tooth structure c. Practically insoluble in oral fluids d. High modulus of resilience 33 / 60 Contamination of zinc-containing amalgam by moisture during triturating or condensation : a. Has no appreciable effect on properties except to the susceptibility to tarnish b. Increases the setting time c. Results in a sharp decrease in flow d. Results in a marked expansion 34 / 60 Setting time of alginate can be better controlled by 😕 a. Temperature of water used of mixing b. Mixing time c. Chemical accelerators and retarders d. Changing water: powder ratio 35 / 60 The function of gum dammar in inlay wax is 😕 a. No smoothness of pattern b. To improve smoothness of pattern c. No resistance to carving d. Less strength to wax 36 / 60 Which of the following statements about compomers are true ? a. They typically are recommended for class II restorations. b. They also are know as GIC c. They are two-paste systems that self-cure within 2 to 3 minutes. d. Because of their resin content, they require a bonding agent for adhesion to tooth structure. 37 / 60 Higher mercury left in an amalgam leads to which of the following ? a. Higher creep b. Higher strength c. High corrosion d. Low corrosion 38 / 60 Clinical significance of smear layer : a. Improve the strength of the composite b. Bonded to tooth structure and prevents composite adhesion c. Increases the bonding action of the bonding agent d. Provides calcium for adhesion of composites 39 / 60 In deep caities, the resin which remains unpolymerized can cause 😕 a. Sagging of restoration b. Secondary caries c. Porosity in restoration d. Pulp inflammation 40 / 60 Which of the following represents the maximum safe concentration of mercury vapor in the breathing zone for a 40-hour workweek ? a. 100 ng Hg/m3 of air b. All are corrects c. 0.05 mg Hg/m3 of air d. 30 ng Hg/m3 of air 41 / 60 Hand instruments for composites are made of 😕 a. Teflon-coated metal b. Stainless steel c. Carbon steel d. Titanium 42 / 60 In visible light-cured composites photo initiator molecule is 😕 a. Camphoroquinone b. Toluidine c. Bis-phenol-A d. Benzoyl methyl ether 43 / 60 The following statements about dental porcelains are true except 😕 a. Crystalline nature b. It is brittle in nature c. Undergoes firing shrinkage d. Undergoes discoloration 44 / 60 A potentially toxic element in base metal alloys is 😕 a. Boron b. Magnesium c. Beryllium d. Molybdenum 45 / 60 Ideal method firing of porcelain is by using 😕 a. Shorter firing at higher temperatures b. Shorter firing at low temperatures c. Longer firing at high temperatures d. Longer firing at low temperatures 46 / 60 Setting of plaster of Paris is a result of 😕 a. Loss of water from hemihydrates b. Indirect interaction between hemihydrates c. Solubility difference between hemihydrates and dehydrate d. Interaction between hemihydrates and water 47 / 60 One of the disadvantages of using quartz as filler in restorative resin is 😕 a. It cannot be polished b. It has low affinity for resin matrix c. It cannot be reduced to the size of microparticle composite d. It cause abrasion and wearing of opposing tooth surface 48 / 60 Hypersensitivity reactions like contact dermatitis is caused by 😕 a. Condensation silicones b. Polysulfides c. Polyether d. Addition silicones 49 / 60 Which of the following statements about laboratory composites are true ? a. Bridge prepared from laboratory composites require a metal substructure. b. Curing using light, heat, and pressure increase the wear resistance. c. Fiber reinforcement increases their strength but decrease their rigidity. d. Restorations prepared from laboratory composites typically are cemented with zinc phosphate cement. 50 / 60 Working time of denture resin should be at least 😕 a. 5 minutes b. 15 minutes c. 10 minutes d. 20 minutes 51 / 60 Which of the following composites give rough surfaced finish ? a. Small particle filled composites b. Conventional composites c. Hybrid composites d. Microfilled composites 52 / 60 Nickel sensitivity in the general population is 😕 a. 11% for women b. 1% in the overall population c. 3% for men d. 3% for women 53 / 60 In an alloy oxygen scavenger is 😕 a. Copper b. Zinc c. Palladium d. Silver 54 / 60 Which one of the following represents the maximum safe concentration of mercury vapor in the breathing zone for a 40-hour work week ? a. 100 mg Hg/m3 of air b. 30 mg Hg/m3 of air c. 0.04 mg Hg/m3 of air d. 0.05 mg Hg/m3 of air 55 / 60 Passiveness of chrome cobalt alloys is due to formation of 😕 a. Cobalt oxide b. Chromium oxide c. Chromium carbide d. Ferric oxide 56 / 60 The restorative material used to restore a small portion of an anterior tooth should have which of the following properties ? a. High strength b. Ease of casting c. Amalgam d. Esthetics 57 / 60 Cobalt-chromium alloy is mostly used for the construction of 😕 a. Subperiosteal b. Endosseus implants c. Intramucosal frames d. Transosteal frames 58 / 60 Carnauba wax is preferred to candelilla wax as 😕 a. It has low melting temperature b. It is sticky c. It provides luster to the pattern d. It is harder and has less flow 59 / 60 The main function of zinc in amalgam is 😕 a. To increase the shelf-life of an amalgam b. To prevent the creep c. To produce delayed expansion d. To increase the longevity of amalgam after setting 60 / 60 Which of the following statements about curing of composites are true ? a. Light from an argon laser will activate polymerization. b. Lights with both blue and red wavelengths are equally effective for polymerization. c. Before light activation, the base and catalyst pastes are mixed. d. Exposure times of 2 to 3 seconds are needed for polymerization with visible light. Your score isThe average score is 0% Facebook 0% Restart quiz Any comments? Send feedback
