1) Which of the following is NOT true of polymethyl methacrylate ? a. Knoop hardness number 18 to 20 b. Tensile strength of 60 MPa c. Density of 1.13 g/cm3 d. Modulus of elasticity of 3.4 GPa
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2) Etchant preferred in gel from than in liquid form________________? a. Better control over placement b. Enhance and concentrate the action of acid c. Helps in visualization while placement d. None of the above
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3) During polymerisation of acrylic resin, above what temperature benzoyl peroxide form freeradicals_______________? a. 25°C b. 37°C c. 50°C d. 60°C
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4) Etching depth after 30 sec for orthodontic bracket with orthophosphoric acid is_________________? a. 10 um – 20 um b. 3 um – 9 um c. 50 um – 110 um d. 200 um – 250 um
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5) The accepted polymer to monomer ratio for packing of polymethyl methacrylate resin is____________? a. 3:1 b. 4:1 c. 10:1 d. 5:1
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6) Residual monomer content of chemically activated resins is______________? a. 0.2% to 0.5% b. 2% to 5% c. 0.3% to 0.5% d. 2% to 5%
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7) Dentin conditioner has the following function______________? a. Removes smear layer b. Increases surface energy of dentin c. Forms a thin resin layer over exposed collagen fibrils d. Helps in bonding with composite
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8) The process wherein two or more chemically different monomers, each with some desirable property, can be combined to yield specific physical properties of a polymer is known as_____________? a. Step-growth polymerization b. Addition polymerization c. Condensation polymerization d. Copolymerization
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9) Denture acrylics contain cross-linking agents mainly to improve their_____________? a. Internal color b. Tissue compability c. Surface hardness d. Craze resistance
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10) Subsurface porosity is due to_____________? a. Thermal changes b. Thickness of the resin c. Lack of temperature d. Packing past the dough stage
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11) If resin is packed in sandy stage what will be seen in the processed denture ? a. Distortion b. Porosity c. Inhomogeneous colour d. Increased strength
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12) Which one of the following is used as filler in composite resins ? a. Quartz b. Silicates c. Zinc particles d. Aluminium
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13) Insufficient closure of the flasks during packing of denture base resin can result in_____________? a. Poor colour stability b. Less polymerization shrinkage c. Increase in vertical dimension d. Decrease in vertical dimension
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14) Quartz tungsten light cure device minimum output of energy should not be less than_____________? a. 300 mw/sm2 b. 350 mw/cm2 c. 400 mw/cm2 d. 450 mw/cm2
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15) Polymerisation of heat-cured methyl methacrylate is initiated by______________? a. Tertiary amine b. Benzoyl peroxide free radical c. Hydroquinone d. Methyl ether
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16) In processing methyl methacrylate, the resin may show porosity if the flask is placed too soon porosity most likely occur_____________? a. Throughout the denture b. Near the borders c. In the thickest part d. On the denture surface
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17) Composite resins in comparison to acrylic have_______________? a. Low compressive strength b. High abrasive resistance c. High water absorption d. High polymerization shrinkage
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18) The chemical used to etch enamel is_______________? a. Zinc oxide b. Methyl methacrylate c. Phosphoric acid d. Eugenol
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19) Which of the following procedure is indicated to produce cross-linking in the polymerization of linear chains of acrylic_______________? a. Addition of grain refining agents b. Addition of difunctional monomers c. Increasing the amount of heat required for linear polymerization d. Incorporation of terminating agents
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20) For photo-curing the composite resin the light source______________? a. Should be held at a millimeter distance from the restoration b. Need no protection while in use c. Will cure composite upto a depth of 5 millimeter thickness d. Is fiber optic
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21) In self-cure acrylic resin, activator is_____________? a. Toluidine b. Quaternary ammonium compound c. Benzoyl peroxide d. Tertiary amine
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22) Marginal leakage related to temperature change occurs to the greatest extent with_______________? a. Amalgam alloy b. Unfilled resin c. Composite resin d. Direct filling gold
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23) Acrylic resins were first introduced as a denture base material in______________? a. 1925 b. 1937 c. 1951 d. 1956
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24) What is the disadvantage of using composites as restorative material ? a. Increased thermal conductivity b. Decreased wear resistance c. Decreased thermal conductivity d. None of the above
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25) The % of free monomer in a heat – cured acrylic resin is_______________? a. 3% to 5% b. 8% to 10% c. 0.2% to 0.5% d. 0.6% to 0.8%
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26) Inadequate pressure application during flasking_______________? a. Increases vertical dimension b. Causes teeth to be shrunken in investment c. Causes poor quality of colour d. Causes fracture of denture
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27) Inorganic phase of the composites aid in_______________? a. Increasing the mechanical strength b. Decreasing the coefficient of thermal expansion c. Reducing the polymerization shrinkage d. All of the above
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28) About polymerization shrinkage of composite all are true, except______________? a. Polymerization shrinkage is greater if bonded surface area is lesser than unbounded surface area b. Polymerization shrinkage is high if within the enamel margins c. Acid etching and priming will decrease polymerization shrinkage d. Microleakage can occur because of polymerization shrinkage
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29) The advantage of unfilled methyl methacrylate is that______________? a. It can be finished smoothly b. It has a low degree of flow c. It’s non-irritation to pulp d. It’s wear resistant is high
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30) Dentin bonding agents usually contain_____________? a. Only Hydrophobic component b. Only Hydrophilic component c. Hydrophobic and hydrophilic component d. Lyophillic and lyophobic component
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31) Which of the following provide opacity to composite ? a. TEGDMA b. BIS-GMA c. Ti02 d. None of the above
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32) The polymerization of self-curing resin takes faster in______________? a. Cold water b. Hot water c. Under pressure d. In vaccum
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33) Acid-etching is done for_______________? a. 30 seconds b. 60 seconds c. 90 seconds d. 120 seconds
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34) No trail closure is necessary with which one of the technique during denture fabrication_____________? a. Compression moulding technique b. Injection moulding technique c. Fluid resin technique d. Light cured technique
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35) The function of the coupling agent in a restorative resin is to allow______________? a. Adhesion of resin particles b. Bonding between filler crystals c. Bonding between filler and resin d. Bonding between tooth and resin
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36) Which of the following constituents is common in occlusal sealants, bonding agents, composite resins ? a. BIS GMA b. Polymethyl methacrylate c. Benzoin methyl ether d. Silica filter
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37) The most important disadvantage of acrylic denture base is_______________? a. porosity b. Shrinkage c. Tooth breakage d. Water absorption
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38) Radio opacity to composite resins is rendered by_______________? a. Silica glass b. Organic matrix c. Barium glass and strontium glasses d. Fluoride particles
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39) Acrylic (cold cure)______________? a. Melts at 100°C b. Softens at 100°C c. Still requires heat for polymerization d. Produces heat during polymerization
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40) Use of dimethyl-P-toluidine is indicated for_______________? a. Thermal polymerization of acrylic b. Chemical polymerization c. Retarding the polymerization reaction d. To inhibit the action of benzoyl peroxide
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