MISCELLANEOUS MCQs _ Dental Material MCQs

MISCELLANEOUS MCQs _ Dental Material MCQs

1. The first reaction after mixing of water with alginate is the reaction of sodium phosphate with
A. Insoluble Ca ions
B. Soluble Ca ions
C. Soluble K ions
D. Insoluble K ions

2. What are the ways to decrease the setting time of alginate impression materials?
A. Increase water temperature
B. Rapid mixing
C. Both A and B
D. Slow mixing

3. The process of absorbing water which leads to expansion of alginate is known as
A. Syneresis
B. Imbibition
C. Sublimation
D. Sintering

4. The process of exudation of the liquid component of a gel which leads to shrinkage of alginate is known as
A. Syneresis
B. Imbibition
C. Sublimation
D. Sintering

5. Major ingredient of alginate impression materials is
A. Sodium alginate
B. Calcium sulfate dehydrate
C. Diatomaceous earth
D. Potassium sulfate

6. Minor ingredient of alginate impression materials is
A. Sodium alginate
B. Calcium sulfate dehydrate
C. Diatomaceous earth
D. Sodium phosphate

7. Consistency and flexibility of set impression of alginate are controlled by
A. Sodium alginate
B. Calcium sulfate dehydrate
C. Diatomaceous earth
D. Potassium sulfate

8. Which of the following ingredients of alginate counteracts inhibiting effect of alginate on stone surface?
A. Sodium alginate
B. Calcium sulfate dehydrate
C. Diatomaceous earth
D. Potassium sulfate

9. The setting time of alginate impression materials is controlled by
A. Sodium alginate
B. Calcium sulfate dehydrate
C. Potassium sulfate
D. Sodium phosphate

10. Type of calcium hemihydrate in dental stone is
A. Alpha
B. Beta
C. Delta
D. Gamma

11. Type of calcium hemihydrate in dental plaster is
A. Alpha
B. Beta
C. Delta
D. Gamma

12. The principal component of dental gypsum products is
A. Calcium sulfate hemihydrate
B. Calcium sulfate dihydrate
C. Potassium sulfate hemihydrate
D. Potassium sulfate dihydrate

13. Types of calcium hemihydrate are obtained through the process of
A. Sintering
B. Fritting
C. Calcination
D. Precipitation

14. The setting reaction of 1 g of calcium hemihydrate yields how much calories
A. 3,100
B. 3,600
C. 3,900
D. 4,100

15. For the impressions of flabby tissues, which of the following impression materials is used?
A. Impression plaster
B. Model plaster
C. Alginate
D. Impression compound

16. Type 2 gypsum product is
A. Impression plaster
B. Model plaster
C. Dental stone
D. High-strength dental stone

17. For diagnostic casts, which of the following materials is used?
A. Impression plaster
B. Model plaster
C. Dental stone
D. High-strength dental stone

18. For master casts for die fabrication, which of the following materials is used?
A. Impression plaster
B. Model plaster
C. Dental stone
D. High-strength dental stone

19. Term gummy smile indicates that when gingival display is
A. >5 mm
B. >3 mm
C. >4 mm
D. <3 mm

20. Gull wing effect is shown by the outline of the incisal edges from
A. Incisor to incisor
B. Canine to canine
C. Premolar to premolar
D. Molar to molar

21. An elastomeric impression material that has an exothermic setting reaction with water as a by-product is
A. Polyether
B. Polysulfide
C. Addition silicon
D. Condensation silicon

22. Polysulfide impressions must be poured within
A. 15 minutes
B. 30 minutes
C. 45 minutes
D. 1 hour

23. Auto-polymerized polymethyl methacrylate shows how much shrinkage during polymerization
A. 0.2%
B. 0.5%
C. 1.0%
D. 1.5%

24. Heat-polymerized polymethyl methacrylate shows how much shrinkage during polymerization
A. 1–7%
B. 2–7%
C. 3–7%
D. 2–3%

25. Best provisional restoration material is
A. PMMA
B. PEMA
C. Bis-acryl
D. All of the above

26. An impression material that sets in a cross-linking polymerization reaction and gives off the by-product ethanol is
A. Polyether
B. Polysulfide
C. Condensation silicones
D. Addition silicones

27. An impression material that changes from a gel to a sol with the application of heat and is reversible with cooling is
A. Polyether
B. Polysulfide
C. Condensation silicones
D. Agar

28. The most popular crown and bridge impression material and there are no by-products of reaction is
A. Polyether
B. Polysulfide
C. Condensation silicones
D. Addition silicones

29. Maximum stress before fracturing is known as
A. Strength
B. Ultimate tensile strength
C. Yield strength
D. Modulus

30. Rigidity or stiffness is determined by
A. Strength
B. Ultimate tensile strength
C. Yield strength
D. Modulus

31. Resistance to permanent deformation is known as
A. Strength
B. Ultimate tensile strength
C. Yield strength
D. Modulus

32. Which of the following is important for wear characteristics and finishing?
A. Strength
B. Ultimate tensile strength
C. Yield strength
D. Hardness

33. Alginate impression material is
A. Expensive compared to other impression materials
B. Easy to use
C. Not affected by gain or loss of water
D. Well known for its long-term stability

34. Impression materials that have mechanical properties permitting considerable elastic deformation but that return to their original form are classified as
A. Thermoplastic
B. Elastometric
C. Inelastic
D. Resins

35. You mix alginate and take an impression. While measuring the water, you got involved in conversation and did not notice how warm it was. It will
A. Make the mix unstable
B. Lengthen the gelation time
C. Not affect the gelation time
D. Shorten the gelation time

36. Which of the following dental materials is an example of an aqueous elastometric?
A. ZOE impression paste
B. Polysulfide
C. Irreversible hydrocolloid
D. Addition silicone

37. The brown paste used in rubber base is called the
A. Polymer
B. Accelerator
C. Base
D. Filler

38. Dental impression compound is known as a/an
A. Chemoplastic material
B. Irreversible material
C. Hydroelastic material
D. Thermoplastic material

39. Which of the following is an example of an inelastic impression material?
A. Polysulfide
B. ZOE impression paste
C. Alginate
D. Addition silicone

40. The term used for the setting of hydrocolloid impression materials is
A. Crystallization
B. Polymerization
C. Curing
D. Gelation

41. The popularity of agar impression materials is limited by the
A. High cost
B. Need for special equipment
C. Poor reproduction of detail
D. Difficulty in pouring the impression

42. When an agar impression slightly contracts and exudes water, it is termed
A. Imbibition
B. Gelation
C. Syneresis
D. Hysteresis

43. Addition silicones are the most popular type of rubber impression material. The reason for this is cost
A. True, false
B. False, true
C. Both true
D. Both false

44. Custom impression trays are made on a model of the patient’s arch. Therefore, to make a custom tray, an alginate impression is also needed
A. True, false
B. False, true
C. Both true
D. Both false

45. A patient came to the clinic and it was found that she needed extensive restorative treatment to which she agreed. You were asked to take impressions as the first step of her care. The impression material of choice would be
A. Agar
B. Alginate
C. Dental impression compound
D. Addition silicone

46. The impression tray that is used to record the prepared tooth, a bite registration, and an impression of the opposing teeth is a
A. Stock tray
B. Custom tray
C. Triple tray
D. Bite registration tray

47. Which of the following impression materials sets by physical means?
A. Agar
B. ZOE
C. Alginate
D. Addition silicone

48. The desirable strength of gypsum materials is __ related to the amount of water used
A. Directly
B. Indirectly
C. Not
D. Partially

49. For gypsum products, a suitable accelerator and retarder, respectively, would be
A. Ethyl alcohol and oleic acid
B. Oleic acid and glycerin
C. Borax and potassium sulfate
D. Potassium sulfate and borax

50. The gypsum material known as “high strength stone” may also be referred to as
A. Plaster
B. Type II stone
C. Type III stone
D. Improved stone

51. The final setting time for gypsum products is typically
A. 15–30 min
B. 30–45 min
C. 45–90 min
D. 90–120 min

52. To make a correct mix for dental stone when using 50 g of powder, the amount of water would be approximately
A. 10–12 ml
B. 14–15 ml
C. 28–30 ml
D. 45–50 ml

53. At a previous appointment, the orthodontist took impressions of patient’s maxillary and mandibular arches. The replicas made from each impression to discuss the treatment plan are termed
A. Casts
B. Dies
C. Study models
D. Molds

54. Quartz in dental porcelain acts as a
A. Binder
B. Frit
C. Opacifier
D. Strengthener

55. Which of the following resins may be classified as thermosetting?
A. Polystyrenes
B. Vinyl resins
C. Epoxy resins
D. Impression compound

56. In general, the hygroscopic expansion of gypsum investments will be higher if they contain
A. Coarser silica particles and alpha hemihydrate
B. Finer silica particles and beta hemihydrate
C. Coarser silica particles and beta hemihydrate
D. Finer silica particles and alpha hemihydrate

57. The cement capable of forming a chemical bond with the tooth structure
A. Reinforced zinc oxide eugenol cement
B. Silicophosphate cement
C. Polycarboxylate cement
D. Composite resin cement

58. Silicate cements are made up of oxide or fluorides of all of the following except
A. Aluminum
B. Tin
C. Calcium
D. Sodium

59. Sodium N-lauroyl sarcosinate is used in dentifrice pastes as a
A. Detergent
B. Humectant
C. Therapeutic agent
D. Binder

60. During the casting of noble metal alloys, the mold should be held at the burn-out temperature for at least
A. 15 minutes
B. 60 minutes
C. 3 hours
D. 6 hours

61. The principal strengthening phases of cerestore, an injection molded ceramic material, are
A. Aluminum oxide and silicon oxide
B. Magnesium silicate and beta-alumina
C. Alpha-alumina and magnesium aluminate spinel
D. None of the above

62. A dental restoration may be tarnished because of
A. Deposition of pigment producing bacteria
B. Surface discoloration
C. Formation of oxides or sulfides
D. All of the above

63. An agar hydrocolloid impression should never be removed from the mouth by a weaving method because this can result in distortion of the impression material
A. Both the statement and the reason are true
B. The statement is true and the reason is false
C. The statement is false but the reason is true
D. Both the statement and the reason are false

64. The principal hardener in noble metal casting alloys is
A. Brass
B. Iron
C. Silver
D. Copper

65. Resins that soften when heated and set on cooling are termed
A. Thermoset resins
B. Irreversible resins
C. Thermoplastic resins
D. Elastomeric resins

66. A compressive stress is always accompanied by
A. An elastic strain
B. A compressive strain
C. A shearing strain
D. A tensile strain

67. Which of the following may result in the expansion of an amalgam restoration made with zinc free alloys?
A. Moisture contamination during condensation
B. High mercury/alloy ratio
C. Under trituration
D. All of the above

68. Self-cured and heat-cured acrylic resins are most similar in respect of which of the following
A. Color stability
B. Curing shrinkage
C. Transverse strength
D. Hardness

69. During the setting of gypsum, the mass thickens and then hardens into needle-like clusters called
A. Spicules
B. Crystallites
C. Spherulites
D. Stellites

70. Which of the following colloidal solutions can be termed aerosol?
A. Liquid in solid
B. Gas in liquid
C. Liquid in air
D. Solid in liquid

71. Which of the following is required for cross-linking for condensation silicone elastomers?
A. Platinum oxide
B. Tin octoate
C. Copper dioxide
D. Calcium sulfate

72. Zinc phosphate cement powder contains all of the following except
A. Zinc oxide
B. Magnesium oxide
C. Bismuth oxide
D. Aluminum phosphate

73. Dental porcelains are manufactured by a process termed
A. Fritting
B. Fusing
C. Vulcanizing
D. Sintering

74. The structure of Dicor, a castable glass ceramic, is essentially composed of
A. Crystalline mica particles
B. Microscopic silica particles
C. Interlocking apatite crystals
D. Microcrystalline quartz particles

75. Strength of gypsum investments is provided by
A. Quartz
B. Dental stone
C. Tridymite and cristobalite together
D. Silica

76. Internal porosity is most likely to occur in which portion of a denture
A. On the surface
B. In those portions located near the flask periphery
C. In the center of a thick portion
D. In the portions having less thickness of resin

77. Invariant transformation is a property of
A. Eutectic and peritectic alloys
B. Peritectic alloys only
C. Eutectic alloys only
D. Solid solutions only

78. The chemical used as a catalyst for the cross-linking of addition silicones is
A. Sulfinic acid
B. Titanium dioxide
C. Platinum salt
D. Palladium salt

79. Which of the following is a thermoplastic material?
A. Impression compound
B. Acrylic resin
C. Dental porcelain
D. Plaster

80. Abrasive used in air polishing agent is
A. NaCl
B. 27 µ alumina particles
C. 50 µ alumina particles
D. Sodium bicarbonate

81. Of all the bevels placed on gold inlay preparation, which is the most important bevel for success of restoration?
A. Occlusal
B. Gingival
C. Axiopulpal
D. Faciopulpal

82. The gingival cavosurface bevel for a class II preparation to receive a cast gold inlay
A. Results in a 300 metal that is burnishable
B. Results in no benefits whatsoever
C. Results in open margin if casting procedures are not accurate
D. Results in difficulty in taking wax patterns

83. Skipping effect is seen in
A. Use of liquid etchant
B. Use of viscous etchant
C. Use of GIC as pit and fissure sealant
D. Use of composite as pit and fissure sealant

84. What is a ferrule?
A. Pin retained restorative preparation
B. Secondary retentive feature for amalgam restoration
C. Band encircling external dimension of tooth
D. Preparation design for composite inlay

85. Transformation toughening is found in ceramics containing
A. Octagonal zirconia
B. Tetragonal zirconia
C. Decahedron zirconia
D. All of the above

86. Similarity in the chemical structure of estrogen is seen with
A. HEMA
B. Polyether
C. Bisphenol A
D. Gutta-percha

87. Which of the following drug is commonly used to control salivation in operative dentistry?
A. Pilocarpine
B. Propranolol
C. Atropine
D. Muscarine

88. Best cement for cementation of porcelain laminate is
A. Dual cure resin
B. GIC
C. Composite
D. Polycarboxylate

89. Glass infiltrated alumina core ceramic is
A. Dicor
B. Inceram
C. Captek
D. IPS-empress

90. Porcelain bonded to metal is strongest when it is
A. Air fired
B. Fired under compression
C. Tempered after firing
D. Fired several times before completion

91. Condensation shrinkage of porcelain during firing depends on
A. Rate of arriving at firing temperature
B. Uniformity of particle size
C. Shape and size of particle
D. Type of investment used

92. To prevent porosity in dental porcelain, it should be baked
A. In the presence of air
B. In vacuum
C. For long period
D. Under pressure

93. Which of the following polishing agents is called whitening agent?
A. Precipitated chalk
B. Iron oxide
C. Chromium oxide
D. Rouge

94. Which of the following should not be used to polish (or) finish amalgam?
A. A ball burnisher
B. A rubber (Burlew) disk
C. Finishing bur
D. A white stone

95. Machineable glass ceramic is
A. Cerestore
B. Décor MGC
C. Infusium
D. Leucite