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 Metal has the following properties except 😕 a. All metals do not have same degrees of strength and plasticity b. Pure metals are not useful in dentistry c. Metal is any element that ionizes positively in solution d. Electroplated silver and copper are used in dies 2 / 60 Which of the following sentences describes the construction of removable partial dentures ? a. They are removable and attached to teeth with clasps. b. Artificial waxes teeth are attached c. Carbone steal d. They are attached to natural teeth with cements, 3 / 60 Which has the highest viscoelastic property and requires more time to recover from deformation ? a. Polysulfide b. Condensation silicone c. Addition silicone d. Polyether 4 / 60 In deep caities, the resin which remains unpolymerized can cause 😕 a. Porosity in restoration b. Pulp inflammation c. Secondary caries d. Sagging of restoration 5 / 60 Which of the following phases in dental amalgam restoration has the best mechanical properties ? a. Ag-Hg b. Sn-Hg c. Cu-Sn d. Ag-Sn 6 / 60 In the cavities which are more than 2mm deep a light-cured restoration is 😕 a. Not indicated b. Cured for longer period c. Fifth generation bonding agent should be applied d. Restoration should be build in increments 7 / 60 Which of the following statements is true regarding zinc phosphate cement ? a. Is used as a permanent restorative material in adults b. Is the oldest luting agent c. Has an obtudant effect on the pulp d. The least irritant to the pulp 8 / 60 For each property, list the amalgam type (irregular low-copper, admixed high-copper, and spherical high-copper ) that has the highest value?. a. Creep irregular low-copper b. 1-hour compressive strength spherical high-copper c. Tensile strength spherical high-copper d. Creep irregular high-copper 9 / 60 Which of the following composites give rough surfaced finish ? a. Conventional composites b. Small particle filled composites c. Hybrid composites d. Microfilled composites 10 / 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 11 / 60 Which of the following represents the maximum safe concentration of mercury vapor in the breathing zone for a 40-hour workweek ? a. All are corrects b. 0.05 mg Hg/m3 of air c. 100 ng Hg/m3 of air d. 30 ng Hg/m3 of air 12 / 60 The common characteristic for pit and fissure sealant composite resins, acrylic appliances and elastomeric impression materials is : a. All of them can be employed as anterior filling materials b. All of them are a result of secondary reaction c. All of them are polymers d. All of them should be heated before using 13 / 60 Setting of plaster of Paris is a result of 😕 a. Solubility difference between hemihydrates and dehydrate b. Loss of water from hemihydrates c. Interaction between hemihydrates and water d. Indirect interaction between hemihydrates 14 / 60 The main function of zinc in amalgam is 😕 a. To prevent the creep b. To increase the shelf-life of an amalgam c. To produce delayed expansion d. To increase the longevity of amalgam after setting 15 / 60 The maximum warpage of acrylic denture occurs during 😕 a. Polishing b. Deflasking c. Curing d. Packing 16 / 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. Expand greatly to provide marginal seal against the tooth d. Properties of amalgam 17 / 60 Zinc oxide eugenal impression should be removed from oral cavity : a. When it can be easily indented by a blunt instrument b. Exactly after four minutes after kneading c. When the material cannot be intended by a blunt instrument d. When the material is glossy 18 / 60 Which of the following base is contraindicated for composites ? a. Zinc oxide eugenol b. Zinc phosphate c. Glass ionomer cement d. Calcium hydroxide 19 / 60 Cavity varnish should not be applied when the following is used as a filling material 😕 a. Direct resin-filling material b. Silicate c. Amalgam d. Zinc phosphate 20 / 60 Dental porcelains are manufactured by a process termed as 😕 a. Fritting b. Fusing c. Sintering d. Vulcanizing 21 / 60 Chemically cured resin shrinks:? a. Away from the light source b. On the surface only c. Towards the center of bulk of material d. On the base only 22 / 60 Carnauba wax is preferred to candelilla wax as 😕 a. It is harder and has less flow b. It provides luster to the pattern c. It is sticky d. It has low melting temperature 23 / 60 Montan waxes have the following properties except 😕 a. Hard, brittle and lustrous b. Obtained by extraction from lignite c. Have low melting points of 42oC d. Are mineral waxes 24 / 60 Which one of the following is not a criterion for a failed high-copper dental amalgam restorations ? a. Micrographs of alloys particles. b. Creep of the restoration out of the cavity preparation in proximal areas c. Marginal ditching along occlusal margins d. Wear facets along the occlusal contach areas 25 / 60 Hypersensitivity reactions like contact dermatitis is caused by 😕 a. Polyether b. Polysulfides c. Addition silicones d. Condensation silicones 26 / 60 The appropriate proportion of polymer to monomer component of dental resin by volume is generally 😕 a. 2:1 b. 1:2 c. 1:3 d. 3:1 27 / 60 The function of gum dammar in inlay wax is 😕 a. To improve smoothness of pattern b. No smoothness of pattern c. No resistance to carving d. Less strength to wax 28 / 60 The impression material which is routinely used in auto mixing devicee system is 😕 a. Condensation silicone b. Polysulfied c. Polyether d. Polyvinyl siloxane 29 / 60 Distortion on removal from undercuts in addition silicones is very less due to 😕 a. Stiffness of the material b. Lowest strain in compression c. Increased strain rate on unset material d. Shrinkage of material 30 / 60 A measure of ductility of a material is referred to as 😕 a. Percentage elongation b. Yield strength c. Flexibility d. Proportional limit 31 / 60 Clinical significance of smear layer : a. Increases the bonding action of the bonding agent b. Provides calcium for adhesion of composites c. Improve the strength of the composite d. Bonded to tooth structure and prevents composite adhesion 32 / 60 Of the four types of gold casting alloys, the most commonly used for crowns and bridges is 😕 a. Type IV b. Type I c. Type II d. Type III 33 / 60 Glass ionomer cenment is not recommended for 😕 a. Class I restoration b. Class IV resoration c. Class V restoration d. Class III restoration 34 / 60 Which of the following composite is recommended for non stress bearing anterior restoration ? a. Microfilled composites b. Hybrid composites c. Small particles d. Conventional composites 35 / 60 Which statements are true for bonding of amalgam to tooth structure ? a. The most effective bonding agents contain copalite. b. The use of amalgam bonding restores the strength of the clinical crown to its original condition. c. The use of amalgam bonding reduces marginal leakage of amalgam restorations. d. Shear bond strength using amalgam bonding to teeth in clinically proven to be as high as that for bonding composites to teeth. 36 / 60 Which one of the following mixing methods permits the escape of dental amalgam mercury vapor ? a. Mixing in a mortar and pestle b. Proportioning mercury and alloy into a friction-fit capsule c. Triturating precapsulated alloy and mercury d. A cover over the mixing arms on a triturator 37 / 60 Strength of dental porcelain is dependent on 😕 a. Composition b. Rough c. No internal structure d. Resistance to fusion 38 / 60 Stearic acid in impression compound 😕 a. Reduces brittleness b. Increase setting time c. Reduces flow d. Reduces plasticity 39 / 60 Adhesion in composites is due to 😕 a. Presence of smear layer b. Cohesion c. True chemical bonding to tooth structure d. Mechanical interlocking 40 / 60 In visible light-cured composites photo initiator molecule is 😕 a. Bis-phenol-A b. Toluidine c. Benzoyl methyl ether d. Camphoroquinone 41 / 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 42 / 60 Which of the following is a measure of resistance to fracture ?: a. Hardness b. Toughness c. Brittleness d. Springiness 43 / 60 The product that is formed on the surface of the amalgam restoration and frequently result in discoloration is 😕 a. Gamma I Phase b. Gamma II Phase c. Oxide d. Sulphide 44 / 60 The noble or base metal alloys used for PFM should have the following requisite : a. Coefficient of thermal expansion should not be compatible with porcelain b. Its melting temperature should be low in comparison with firing temperature of porcelain c. Should bond with dental porcelain d. Should be brittle 45 / 60 All are properties of waxes except 😕 a. Plastic deformation b. Creep c. Solidification shrinkage d. Flow 46 / 60 One of the disadvantages of using quartz as filler in restorative resin is 😕 a. It has low affinity for resin matrix b. It cannot be reduced to the size of microparticle composite c. It cause abrasion and wearing of opposing tooth surface d. It cannot be polished 47 / 60 Commonly used filler in composite is 😕 a. Aluminum b. Colloidal silica c. Glass d. Quartz 48 / 60 The main resin constituent of polishable composite resin is 😕 a. Urethane dimethacrylate b. Polycaronate c. Cyanoacrylate d. Polymethyl methacrylate 49 / 60 Pick out the incorrect statement regarding alginate impressions 😕 a. Will be shrink as a result of syneresis b. Will take up water and expand if kept wet c. Is an irreversible hydrocolloid impression material d. May exhibit a fluid exudates on the surface as a result of imbibitions 50 / 60 The following statements about dental porcelains are true except 😕 a. Undergoes discoloration b. Crystalline nature c. Undergoes firing shrinkage d. It is brittle in nature 51 / 60 Light source in the curing unit is usually 😕 a. Sun light b. Infra red bulb c. Ultraviolet light bulb d. Tungsten halogen light bulb 52 / 60 Commonly used coloring agent in impression plaster is 😕 a. Alizarin red b. Metallic oxide c. Congo red d. Indigo dye 53 / 60 The gelation temperature of agar hydrocolloid impression material should be 😕 a. 45-600C b. 100C higher than mouth temperature c. Far below the oral temperature d. 37-450C 54 / 60 When the gold content of gold alloys increases 😕 a. The corrosion resistance increases b. Ductility decrease c. The hardness decrease d. The percentage elongation decrease 55 / 60 Gold casting alloys are classified as type I, II, III or IV among these, having highest hardness is 😕 a. Type II b. Type I c. Type III d. Type IV 56 / 60 A potentially toxic element in base metal alloys is 😕 a. Magnesium b. Boron c. Beryllium d. Molybdenum 57 / 60 Acrylic resins are used in which of the following ? a. Ceramic ( porcelain )-fused-to-metal crowns b. Anterior onlays c. Denture bases d. Posterior inlays 58 / 60 Ideal method firing of porcelain is by using 😕 a. Longer firing at high temperatures b. Shorter firing at higher temperatures c. Longer firing at low temperatures d. Shorter firing at low temperatures 59 / 60 Cobalt-chromium alloy is mostly used for the construction of 😕 a. Transosteal frames b. Subperiosteal c. Intramucosal frames d. Endosseus implants 60 / 60 Which of the following sentences describes the construction of removable partial dentures ? a. They are attached to upper natural teeth with cements, b. Artificial acrylic teeth are attached c. They are attached to lower natural teeth with cements, d. They are attached to natural teeth with cements, Your score isThe average score is 0% Facebook 0% Restart quiz Any comments? Send feedback
