Test 1 Past Paper PDF

Test 1 1.Mark the correct statement: The surface of a body has lower energy than its interior The bond strength between the building blocks is directly proportional to the surface energy The surface energy of metal oxides is lower than that of liquids Surface tension characterises the free surface...

Test 1 1.Mark the correct statement: The surface of a body has lower energy than its interior The bond strength between the building blocks is directly proportional to the surface energy The surface energy of metal oxides is lower than that of liquids Surface tension characterises the free surface energy of solids 2.Mercury is characterised by the following: Main constituent of cermet cements Specific velvet colour Component of dental amalgam Boils at 689.5 degrees 3.Opalescence is: A process where certain optical media reflect light rays of shorter wavelengths and transmit those of longer wavelengths. Nearly all incident light can pass through the irradiated body. Property of some substances to let light through them so that an object cannot be seen clearly through the substance A process by which a particular body absorbs radiation of a particular wavelength and emits light of a longer wavelength. 4.Which of the following applies to primary tests for determining the biological properties of dental materials? Closest to the actual clinical situation Legal and other restrictions High cost Ease of standardisation 5.Gold alloys of the fourth type are used to fabricate: Overlay Crowns Frameworks for partial dentures Bridges up to three units 6.Which of the following is not considered a noble metal in dentistry: Palladium Gold Silver Osmium 7.Mark the correct statement: There is electron sharing in secondary chemical bonds There is no electron sharing in primary chemical bonds Ionic chemical bonds are characterised by electron sharing Hydrogen chemical bonds are characterised by electron sharing 8.Mark the CORRECT statement: Waxes are hydrophilic materials Waxes are a mixture of esters of higher fatty acids and alcohols Waxes are thermosetting materials Waxes are insoluble in organic solvents 9.When two complementary colours are mixed in equal proportion, the following is obtained: Grey Depends on the complementary colours White Black 10.Zinc-phosphate cement is mixed on the: On the glass slab, heated to 37 degrees The rough side of the glass slab The smooth side of the glass slab In large portions 11.The Vickers hardness test uses the following: A Pyramid A Diamond cone A Diamond prism A Polymer needle 12.Dental amalgam is defined as The alloy of cement and metals The alloy of Metals and polymers The alloy of mercury, silver and other metals The alloy of precious metals with copper 13.All materials are auxiliary EXCEPT: Hydrocolloids Additive silicone Glass ionomer cement Gypsum 14.The aggregate state characterised by the lowest energy of substances is: Plasma Gaseous Solid Liquid 15.Mark the correct statement: The coefficient of thermal expansion can characterise the volumetric, surface and linear expansion of materials Thermal conductivity of materials is defined as the amount of heat in microsieverts that passes through 1 meter of material with a cross-section and square centimetre Thermal properties of dental materials refer to the response of a material to an applied pressure Thermal conductivity of materials is defined as their ability to change to different aggregate states when heat is applied 16.Mark the correct statement: The property of substances to form a large contact angle with water is defined as hydrophilicity. The property of substances to form a small contact angle with water is defined as hydrophilicity The property of substances to form a large contact angle with water is defined as lipophilicity The property of substances to form a small contact angle with water is defined as hydrophobicity 17.Noble metals in dentistry are: Ruthenium, Platinum, Silver Silver, Osmium, Iridium Tin, Lead, Potassium Iridium, Osmium, Ruthenium 18.The fractures in metal-ceramic indirect restorations can be: Combined (mixed) Adhesive Cohesive All are true 19.Mark the correct statement: Copper in dental amalgam reduces strength and hardness Copper in dental amalgam increases volumetric expansion Copper in dental amalgam reduces corrosion resistance Copper in dental amalgam binds readily to mercury 20.Mark the correct statement: Artificial porcelain teeth for dentures adhere better to the denture base than acrylic ones Porcelain denture teeth are lighter than acrylic denture teeth Porcelain denture teeth are more wear-resistant than acrylic denture teeth Acrylic denture teeth have better colour stability compared to porcelain artificial teeth 21.The tensile strength test is: Static non-destructive method Dynamic destructive method Dynamic non-destructive method Static destructive method 22.The force of London is characteristic of: The dipole relationship in the metallic bond The ionic bond The covalent bond Van der Waals forces of attraction 23.The ratio of elements in the alloy composition at which the lowest melting point is achieved is defined as: Thermal equilibrium Eutecticum Binary Poisson's ratio 24.Which test determining the biological properties of dental materials allows for interaction between an INTACT BIOLOGICAL SYSTEM and the material being tested? Use tests Animal tests All answers are correct Primary tests 25.The powder of conventional glass ionomer cement is: Magnesium oxide and phosphates Spinel Silica Calcium aluminium fluorosilicate glass 26.Triethylene glycol dimethacrylate is Monomer in heat-activated acrylic resins for denture bases Monomer in microwave-activated acrylic resins for denture bases Component of composite restorative materials Soft silicone denture relining materials 27.Silicate and Silicophosphate cement: Are all true Are precursors of glass ionomer cement Have a toxic effect on dental pulp Have historical significance 28.A characteristic of Chromium-Nickel Martensitic steels is: Have a volume-centered tetragonal lattice Contain 18% Nickel The amount of carbon is 14% Contain 50% chromium 29.Pickling is: The process of cleaning tooth enamel of organic contaminants by the application of acid solutions Process of preparation for bonding of polycrystalline ceramic materials by application of acid solutions No correct answer The process of cleaning metal surfaces of oxides and other contaminants by immersion in acid solutions 30.ISO Class IV gypsum is characterised by: High strength and low expansion High strength and high expansion Low strength and high expansion Low strength and low expansion 31.A gold alloy graded 750 contains: 22-karat gold 16-karat gold 18-carat gold 24-carat gold 32.Which of the following statements best describes absorption? Bonding of the building blocks within a material Atoms or molecules of a substance penetrate through the surface of a liquid or solid material Atoms or molecules of a substance are retained on the surface of a liquid or solid material Bonding of the building blocks of different materials 33.Alloys are characterised by: Melting interval Heat absorption on the transition from liquid to solid Heat release on the transition from solid to liquid Melting point 34.The ~SH group is characteristic of the following: Silicones Hydrocolloids Polysulfide rubbers Polyether rubbers 35.Deformation, where the material regains its size and shape after the cessation of external forces, is defined as: Elastic Plastic Static Creep 36.Feldspar is a major ingredient in: Low-melting porcelains Zirconia-reinforced aluminium ceramics Zirconia-silica ceramics in a resinous interpenetrating matrix Polycrystalline ceramics 37.Mark the correct statement The relationship between the class (number) of dental plaster and the amount of water required to mix it is directly proportional Type 2 dental plaster has lower strength than type 1 The amount of water, mixing time and compressive strength of gypsum products are not related The water/powder ratio of Class 4 and Class 5 plaster products is similar 38.Mark the correct statement: Electric current is the chaotic movement of electric charges whose carriers may be non-metals and their oxides Electric current is the flow of electrical charges whose carriers may be electrons or ions Electric current is the directed movement of photons, the carriers of which may be electrons or ions Electric current is the chaotic movement of electric charges whose carriers are not electrons or ions 39.Mark the correct statement: When soldering, an alloy with the same melting temperature as the elements to be joined is selected No correct answer When soldering, the surfaces to be joined are treated with flux When welding, an additional material (solder) is used to make the connection between the two units 40.Polyether impression materials: Are thermoplastic materials Are of the Hydrocolloid group Form a large contact angle with water Form a small contact angle with water 41.Which of the following is not an organisation for standardisation in dentistry? FDA FDI UEFA ISO 42.Of the tests determining the biological properties of dental materials, the inhalation test belongs to the group: Diffusion filter testс Primary tests Use tests Secondary tests 43.In the four-point bending test: There is one support and three load points There are four supports and four load points There are two supports and two load points There are three supports and one load point 44.Which substances exhibit isotropic properties: All answers are correct Gases Amorphous substances Liquids 45.Which of the following materials is crystalline below 36°C and amorphous above 52°C Composite resins Wax Acrylic polymers Rubber 46.What is the initiator of polymerisation in heat-polymerising acrylic resins for denture base fabrication? Ethylene Glycol Polyether ketone Lead Benzoyl peroxide 47.Impressions with plaster of Paris are indicated for: Impressions for partial crowns Partially edentulous patients Impressions for fixed partial dentures (bridge) Completely edentulous patients 48.According to their use, ceramic materials are divided as follows: For reinforcing veneering porcelains, veneering ceramic materials, for fabrication of artificial denture teeth High temperature, medium-high temperature, low temperature and extremely low temperature Feldspathic, synthetic, glass infiltrated Polycrystalline, vitreous, nanoceramics 49.Shore A hardness test: Examines the instantaneous hardness of ceramic materials Tests the hardness of alloys Tests the hardness of elastomers Examines the hardness of plastics 50.Oral electro galvanism is characteristic of: Amalgams Acrylic partial dentures Composite restorations Ceramic partial crowns 51.Which statement is true for the suction chamber used in the process of casting: The suction chamber is used to evacuate gasses formed during the casting process The suction chamber is placed in the volumetric centre of the mould The suction chamber placed in the thermal centre of the mould A suction chamber is never used 52.A mineral that consists of mixed metal oxides is called: Spinel Glaze Polycrystalline ceramics Leucite 53.Mark the correct statement: Composite restorations are less corrosion-resistant than amalgams Recrystallisation reduces the potential for corrosion Amalgams are more resistant to corrosion than gold restorations Corrosion only affects the surface of the restorations 54.The main setting reaction of compomers is: Acid-base reaction Polymerisation Cooling No correct answer 55.Glass ionomer cement reinforced with metal particles is known as: Kermet Geomers Ormosers Oligomers 56.A simple cubic crystal lattice contains: Nine atoms Eight atoms Four atoms Seven atoms 57.Antifluxes are used for: Insulating the metal surface before bonding Dissolving metal oxides Etching the enamel Limiting solder flow 58.For which material mixing with latex gloves is not indicated due to inhibition of the polymerisation reaction: Additional silicones Gypsum Zinc oxide eugenol pastes Hydrocolloids 59.Base alloys are those which: Contain at least 40% gold and 60% precious metals Contain less than 25% precious metals Contain only precious metals Contain more than 25% precious metals 60.The γ phase in traditional silver-tin amalgam alloys is: Cu6Sn5 Sn4Hg2 Ag-Cu Ag3Sn 61.The polymer in heat-polymerising acrylic resins for denture base fabrication is characterised by the following: Solid state at room temperature Liquid state at a temperature of 60 degrees Purple colour High volatility 62.Mark the correct statement for Cobalt-chromium-molybdenum alloys: Excellent biocompatibility, relatively high process sensitivity, good bond to porcelain, low cost High cost, poor biocompatibility, relatively high technological sensitivity, good bond to porcelain, low cost Excellent biocompatibility, low technological sensitivity, poor bond to porcelain, low value Very high density, relatively low technological sensitivity, good bond to porcelain, high cost 63.Temporary obturation materials are divided into two main groups: Composite and zinc oxide Glass ionomer and modified glass ionomer Eugenol-containing and aneugenol-free Glass ionomer and zinc oxide 64.Mark the correct statement: Silicate investment materials undergo expansion during their setting and initial heating stages Silicate investment materials have a high heating strength Silicate investment materials have a lower density than phosphate investment materials High heating strength lowers the technological sensitivity of silicate investment materials 65.The micro-cracks produced in the sintering process that are relevant to fractures in porcelain are called: Godon defects Goldstein defects Griffith defects Growth defects 66.Light in the visible spectrum is defined as electromagnetic radiation of wavelength: 380 - 750 nanometres 380 - 750 millimetres 380 - 750 micrometres 380 - 750 picometres 67.In the Vita 3D Master shade guide: Chroma is the leading feature The Chroma of the shade tabs changes in the vertical direction There are four groups - A,B,C,D Smaller number indicates lower brightness 68.To define a material as porcelain, the following component is mandatory: No correct answer Quartz Feldspar Kaolin 69.Typical symptoms of oral electro galvanism are: All are true Increased tooth sensitivity Burning, tingling Metallic taste 70.Mark the WRONG statement: Alginate impression materials are cast immediately (up to 30 minutes) after being taken Silicone impressions are stored at room temperature until cast Silicone impressions are cast immediately (up to 30 minutes) after they are taken Special thermosetting resins are used to create a pattern from an optical impression 71.The liquid of polycarboxylate cement is: An аqueous acetic acid solution An aqueous solution of hydrofluoric acid An aqueous solution of polyacrylic acid An aqueous solution of orthophosphoric acid 72.Which statement is true about the quality transparency of materials: Transparency is a chemical characteristic of material media, a measure of their permeability to electromagnetic waves or other types of radiation Transparency is a physical characteristic of material media, a measure of their permeability to electromagnetic waves or other types of radiation No statement is true Transparency is a physical characteristic of material media, a measure of their transmittance to heat 73.The chemical formula of Cristobalite is: K2O.Al2O3.6SiO CaSO4 SiO2 K2O.Al2O3.4SiO2 74.Recrystallisation is a technological process characteristic of: Polymer materials Composite materials Alloys Enamel 75.In the Vita Classic shade guide: A smaller number indicates lower vitality There are four groups - A, B, C, D Vitality is a leading feature The Chroma of the shade tabs changes vertically 76.The most important characteristic for correct colour reproduction of indirect restorations is: Translucency Value Chroma Hue 77.What are the main indicators characterising colour in the Munsell system? Density, Lightness, Translucency Hue, Transparency, Translucency Hue, Vitality, Chroma Hue, Transparency, Chroma 78.The main setting reaction of resin-modified glass ionomer cement is: Neutralisation Polymerisation Polycondensation Devitrification 79.Which of the following statements is true for the spontaneous jumping of atoms in the crystal lattice: This process is defined as Diffusion This process is characteristic of low temperatures This process is characteristic of polymers This process is characteristic of ceramics 80.Technological properties of materials are: Plasticity, Rolling, Forging, Welding, Shrinkage, Drawing, Drilling, Thinness Plasticity, Cutting, Expansion, Welding, Rolling, Drawing, Drilling, Thinness Plasticity, Forging, Welding, Rolling, Drawing, Drilling, Cutting, Thinness Plasticity, Forging, Welding, Sintering, Rolling, Drawing, Drilling, Cutting 81.Which statement is true for the tensile strength test for brittle materials: The limit of proportionality coincides with the fracture zone The plastic deformation zone is similar to that of pure metals The yield zone is increased relative to alloys The tensile strength test does not test brittle materials 82.In commercially pure titanium: Vickers hardness is variable on the surface and in-depth of the test sample Has poor corrosion resistance Does not react with investment materials when cast Forms a passivation layer with a thickness of 200-500 μm 83.Which of the following can lead to deterioration of corrosion resistance, allergic reactions, and formation of nitrides, oxides and carbides in casting alloys? Using the same pot (crucible) to cast different alloys Melting the casting alloy by spark erosion Using a volt arc to melt the casting alloy All are correct 84.The γ 2 phase in traditional amalgams is: The compound of copper with tin The compound of silver with mercury The compound of silver with copper The compound of tin with mercury 85.In Mohs' table of mineral hardness, the fourth in order is: Calcite Fluorite Topaz Apatite 86.The polishing of heat-cured acrylic resins for denture base fabrication ends with: Soft bristle brush and polishing paste Rubbers Hard bristle brush and polishing paste Soft bristle brush (felt) 87.What do the last three digits of the 13-digit ISO code for turbine burs indicate? Type of attachment The size and shape of the abrasive The largest diameter of the working part The file material 88.Nickel Allergy: Occurs more frequently in women Does not occur in metal-ceramic restorations Occurs more frequently in men Has no clinical significance 89.Dental gypsum powder 1st class: Is a beta form of calcium sulphate hemihydrate Is an alpha form of calcium sulfate dihydrate Is calcium sulfate dihydrate Should be mixed with a special liquid 90.Dental implants and active therapeutic appliances with potential health risks fall into the following category: Class 1 Class 2a Class 2b Class 4 91.Of the tests determining the biological properties of dental materials, the implantation test belongs to the group: Diffusion filter tests Primary tests Usage tests Secondary tests 92.Sintering is defined as: The process of heating closely packed particles to a specific temperature equivalent to the melting point of the base element The process of heating closely packed particles to a specified temperature higher than the melting point of the base element The process of heating closely packed particles to a specified temperature below the melting point of the base element The process of cooling closely packed particles of material to room temperature 93.Two objects that are colour matched under the irradiation of all possible light sources are called: Calibration pair Amorphous pair Isomeric pair Metameric pair 94.An inhibitor used in heat-polymerising acrylic resins for denture base fabrication is: Methacrylic acid Polyether rubber Dibutyl-n-phthalate Hydroquinone 95.Mark the correct statement: Slow cooling of the alloy results in the fixation of a hard but brittle structure of the cast component When casting an alloy, heating is required until the melting point of the alloy is reached Centrifugal forces are used in casting machines to allow the molten alloy to fill the mould's details Rapid cooling after casting results in an increase in the ductility and malleability of the alloy 96.Mark the WRONG statement: Ceramic materials dissolve when fluorides are applied The surface of ceramic restorations is stable Ceramic materials do not emit harmful products Ceramic materials are chemically reactive materials 97.Which of the following classes of material is defined as an auxiliary: Cement Ormosers Polysulfide rubbers Amalgams 98.Mark the WRONG statement: Lithium disilicate ceramics can be acid-etched with hydrofluoric acid Feldspathic porcelains can be acid-etched with hydrofluoric acid Polycrystalline ceramics can be acid-etched with hydrofluoric acid Glass-ceramics can be acid-etched with hydrofluoric acid 99.All main groups are equally subdivided into four subgroups in which shade guide: Vita Classical Bioform Vita 3D master Chromascope 100.The phase (allotropic) transformation of titanium at 882 degrees Celsius determines the following: Two forms α and β Three polymorphic forms - type 1, type 2 and type 3 Four forms α, β, ∞, π Six forms α, β, ∞, π, Ω, ¥