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 Which of the following statements about compomers are true ? a. They are two-paste systems that self-cure within 2 to 3 minutes. b. They also are know as GIC c. They typically are recommended for class II restorations. d. Because of their resin content, they require a bonding agent for adhesion to tooth structure. 2 / 60 Commonly used viscosity controller in composites is 😕 a. TEG-DMA b. Polyurethanes c. Bis-GAM d. Methyl methacrylate 3 / 60 Excess composite from the labial surfaces can be removed by using 😕 a. Carbide burs at high speed b. Diamond burs at high speed c. Carbide burs at low to medium speed d. Diamond burs at low to medium speed 4 / 60 In UV curing system the activator employed is 😕 a. Dibutyl phthalate b. Methyl methacrylate c. Hydroquinone d. Benzoin methyl ether 5 / 60 Materials having coefficient of thermal expansion close to the tooth structure 😕 a. Glass ionomer cement b. Silicate cement c. Amalgam d. Unfilled 6 / 60 The type of stress to which dental amalgam is more resistant to 😕 a. Shear stress b. Impact stress c. Compressive stress d. Tensile stress 7 / 60 Which one of the following mixing methods permits the escape of dental amalgam mercury vapor ? a. Proportioning mercury and alloy into a friction-fit capsule b. A cover over the mixing arms on a triturator c. Triturating precapsulated alloy and mercury d. Mixing in a mortar and pestle 8 / 60 Which of the following is called periphery wax ? a. Utility wax b. Bite registration wax c. Beading wax d. Sticky wax 9 / 60 The byproduct in condensation silicones is 😕 a. Butyl alcohol b. Ethyl alcohol c. Propyl alcohol d. Methyl alcohol 10 / 60 Stearic acid in impression compound 😕 a. Reduces flow b. Reduces plasticity c. Increase setting time d. Reduces brittleness 11 / 60 Inorganic phase in a composite matrix 😕 a. Decreases the mechanical strength b. Increases coefficient of thermal expansion c. Increases the mechanical strength d. Increases the polymerization shrinkage 12 / 60 Commonly used coloring agent in impression plaster is 😕 a. Congo red b. Alizarin red c. Indigo dye d. Metallic oxide 13 / 60 The temperature at which a solid changes to liquid is known as its 😕 a. Heat temperature b. Temperature of specificity c. Vapor temperature d. Fusion temperature 14 / 60 Which of the composites with the following fillers may be radiopaque ? a. Lithium aluminum silicate b. Quartz c. Barium glass d. Colloidal silica 15 / 60 The purpose of burnishing the amalgam after condensation is to 😕 a. Reduce surface microporosities b. To prevent recurrent carries c. To reduce discoloration d. To reduce gamma II particule 16 / 60 Dispensing composite resins using a syringe is advantageous because it 😕 a. Increases surface smoothness b. Conserves the material c. Decreases air voids in the restoration d. Increases strength and abrasive resistance 17 / 60 Thermal conductivity is proportional to 😕 a. Type of metal b. Area of conduction c. Hardness of metal d. Fusion temperature 18 / 60 The light from the visible light curing unit can cause 😕 a. Iritis b. Corneal ulceration c. Cataract d. Retinal damage 19 / 60 For each property, list the amalgam type (irregular low-copper, admixed high-copper, and spherical high-copper ) that has the highest value?. a. Tensile strength spherical high-copper b. Creep irregular high-copper c. Creep irregular low-copper d. 1-hour compressive strength spherical high-copper 20 / 60 Thickness of the gel between the tray and tissue for either agar or alginate should always be at least 😕 a. 1 mm b. 3 mm c. 4 mm d. 2 mm 21 / 60 Cobalt-chromium alloy is mostly used for the construction of 😕 a. Endosseus implants b. Intramucosal frames c. Subperiosteal d. Transosteal frames 22 / 60 Which of the following statements is true regarding zinc phosphate cement ? a. Has an obtudant effect on the pulp b. The least irritant to the pulp c. Is used as a permanent restorative material in adults d. Is the oldest luting agent 23 / 60 The reason for hydroxyapatite coating on implant biomaterials is 😕 a. Greater bony opposition b. Presence of fibrous tissue c. Lesser bony apposition d. Prolonged healing time 24 / 60 Which of the following occurs when dental amalgam is overmixed ? a. Tensile strength increases b. Compressive strength decreases c. Corrosion decreases d. Corrosion increases 25 / 60 The desirable quality of porcelain is 😕 a. Requirement of color b. Toughness without brittleness c. Thermal expansion d. Translucency 26 / 60 Spot out incorrect statement regarding zinc in dentistry 😕 a. Pure zinc has no application in dentistry b. It does not oxidize c. It is low in strength d. It is relatively soft and ductile 27 / 60 The most commonly used implant type presently is 😕 a. Intramucosal implant b. Transosteal implant c. Endosseous d. Subperiosteal 28 / 60 The common characteristic for pit and fissure sealant composite resins, acrylic appliances and elastomeric impression materials is : a. All of them should be heated before using b. All of them are a result of secondary reaction c. All of them can be employed as anterior filling materials d. All of them are polymers 29 / 60 The reason zinc oxide eugenol cement is used as a temporary restoration 😕 a. It has an obtudant effect b. It has poor tensile strength c. It does not form reparative dentin d. It does not have anticariogenic activity 30 / 60 In alginate impression the final gel is 😕 a. Sodium sulphate b. Calcium alginate c. Calcium sulphate d. Sodium alginate 31 / 60 Sulfur contamination from natural latex gloves inhibits the setting of 😕 a. Zinc oxide eugenol impression paste b. Polyether c. Alginate d. Polyvinyl siloxane 32 / 60 The strain at which the plastic strain develops may be represented by 😕 a. Elastic limit, yield strength, proportional limit b. Toughness, rigidity, resilience c. Yield strength, tensile strength, toughness d. Elastic limit, modulus of elasticity, tensile strength 33 / 60 A direct restorative material used frequently to restore a portion of a posterior tooth that is subject to large biting forces would possess which of the following properties ? a. Ease of casting b. Esthetics c. High strength d. Thermal insulation 34 / 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. 30 mg Hg/m3 of air b. 0.05 mg Hg/m3 of air c. 100 mg Hg/m3 of air d. 0.04 mg Hg/m3 of air 35 / 60 Which of the following is a measure of resistance to fracture ? a. Brittleness b. Springiness c. Toughness d. Hardness 36 / 60 Light source in the curing unit is usually 😕 a. Tungsten halogen light bulb b. Sun light c. Infra red bulb d. Ultraviolet light bulb 37 / 60 Which of the following components acts as a refractory material in porcelain ? a. Feldspar b. Silica c. Kaolin d. Potash 38 / 60 Greater ratio fo zinc oxide to eugenol will have the following effect on setting time 😕 a. Depends on rate of mixing b. Increases setting time c. Does not alter setting time d. Decreases setting time 39 / 60 Which of the following office conditions minimize the health hazard from spilled mercury ? a. Amalgam scrap stored in a closed container b. Baseboard heating c. Floor carpeting d. Wall carpeting 40 / 60 Clinical significance of smear layer : a. Provides calcium for adhesion of composites b. Improve the strength of the composite c. Bonded to tooth structure and prevents composite adhesion d. Increases the bonding action of the bonding agent 41 / 60 The most commonly employed alloy combination for use in implants is 😕 a. Titanium-platinum-aluminum alloy b. Titanium-molybdenum-vanadium alloy c. Titanium-aluminum-vanadium alloy d. Platinum-aluminum-vanadium alloy 42 / 60 Gold casting alloys are classified as type I, II, III or IV among these, having highest hardness is 😕 a. Type I b. Type II c. Type IV d. Type III 43 / 60 Which of the following is recommended as an adhesive to trays with polysulfides ? a. Polydimethyl siloxane b. Acrylic resin c. Ethyl silicate d. Styrene-acrylonitrile 44 / 60 Resistance of a liquid to motion is called 😕 a. Diffusion b. Creep c. Springiness d. Viscosity 45 / 60 Ideally, the set amalgam should do which of the following ? a. Have little dimensional change b. Shrink significantly to provide space for correction products to seal the margins c. Properties of amalgam d. Expand greatly to provide marginal seal against the tooth 46 / 60 Which of the following initiator-accelerator systems is needed for a light-activated composite? a. Diketone-amine b. Peroxide-amine c. Organic acid-metal ion d. Organic acid-peroxide 47 / 60 Hypersensitivity reactions like contact dermatitis is caused by 😕 a. Polysulfides b. Addition silicones c. Polyether d. Condensation silicones 48 / 60 Biting force in the molar region ranges from 😕 a. 600-1000 N b. 1000-1300 N c. 900-1000 N d. 400-890 N 49 / 60 Binder in the phosphate investment is 😕 a. Phosphoric acid b. Manganese dioxide c. Magnesium oxide and monoammonium phosphate d. Cristobalite 50 / 60 Which of the following phases in dental amalgam restoration has the best mechanical properties ? a. Ag-Hg b. Ag-Sn c. Cu-Sn d. Sn-Hg 51 / 60 Conventional dental amalgam alloy contains 😕 a. Silver, mercury, copper and zinc b. Silver, tin, copper and zinc c. Silver, mercury, copper and mercury d. Silver, tin, palladium and zinc 52 / 60 The restorative material used to restore a small portion of an anterior tooth should have which of the following properties ? a. Ease of casting b. High strength c. Amalgam d. Esthetics 53 / 60 Which statements are true for bonding of amalgam to tooth structure ? a. The use of amalgam bonding reduces marginal leakage of amalgam restorations. b. Shear bond strength using amalgam bonding to teeth in clinically proven to be as high as that for bonding composites to teeth. c. The most effective bonding agents contain copalite. d. The use of amalgam bonding restores the strength of the clinical crown to its original condition. 54 / 60 Main disadvantage of denture base soft reliner is 😕 a. It can not lead to fungal growth b. It can be cleaned properly c. It has not to be changed over a period of time d. It can not lead to cleaned property 55 / 60 Greening effect of porcelain is due to 😕 a. Palladium b. Platinum c. Silver d. Golde 56 / 60 The maximum warpage of acrylic denture occurs during 😕 a. Polishing b. Packing c. Deflasking d. Curing 57 / 60 Glass ionomer cenment is not recommended for 😕 a. Class III restoration b. Class IV resoration c. Class V restoration d. Class I restoration 58 / 60 Which of these statements are correct in terms of preparing a correctly triturated mass of amalgam ? a. An overmixed mass is removed readily from the capsule but is soupy in appearance. b. An undertriturated mass is crumbly and dull. c. A correctly triturated mass is a smooth homogeneous, and dull. d. Dental amalgam is a mixture of silver alloys and mercury. 59 / 60 For luting purpose, the film thickness should be 😕 a. 25 μm or less b. up to 75 μm c. minimum 50 μm d. ideally 100 μm 60 / 60 The main advantage of composites compared to silicates cement is 😕 a. Coefficient of thermal expansion close to tooth structure b. Practically insoluble in oral fluids c. High modulus of resilience d. Color matching with the tooth structure is excellent Your score isThe average score is 0% Facebook 0% Restart quiz Any comments? Send feedback
