Biomaterial Test

5 votes, 5 avg

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Biomaterial Test

1 / 60

Which of the following is the best choice of restorative material to achieve moderate to high strength, fluorite release, and esthetics ?

a. Glass ionomer

b. Compomer

c. Hybrid ionomer

d. Composite

2 / 60

Working time of denture resin should be at least 😕

a. 5 minutes

b. 15 minutes

c. 10 minutes

d. 20 minutes

3 / 60

Commonly used viscosity controller in composites is 😕

a. Bis-GAM

b. Methyl methacrylate

c. TEG-DMA

d. Polyurethanes

4 / 60

Acrylic resins are used in which of the following ?

a. Anterior onlays

b. Denture bases

c. Ceramic ( porcelain )-fused-to-metal crowns

d. Posterior inlays

5 / 60

Porcelain-bonded to metal is stronger when fired 😕

a. After metal is tempered

b. Under compression

c. Several times in air

d. Under low temperature

6 / 60

Property which distinguishes composites from filled acrylic resins 😕

a. Adhesive bonding between matrix and filler

b. Bonding between coupling agent and filler

c. Bonding between coupling agent and tooth structure

d. Bonding with tooth structure

7 / 60

Which one of the following is not a criterion for a failed high-copper dental amalgam restorations ?

a. Creep of the restoration out of the cavity preparation in proximal areas

b. Marginal ditching along occlusal margins

c. Micrographs of alloys particles.

d. Wear facets along the occlusal contach areas

8 / 60

Noble metal alloys are classified according to their 😕

a. Dental function

b. Melting temperature

c. Castability

d. Malleability

9 / 60

The constituent that acts as a binder in the investment is 😕

a. Water

b. Quartz

c. Gypsum

d. Silica

10 / 60

Oil of clove is sometimes used in preference to eugenal in ZOE paste because :

a. Reduces burning sensation of paste

b. To increase setting time

c. It increases mixing property of paste and therefore improves impression recorded

d. Has a better reaction with zinc oxide

11 / 60

A small portion of an anterior tooth would most likely be restored with which of the following ?

a. Gold alloy

b. Amalgam

c. Composite resin

d. Porcelain

12 / 60

The type of stress to which dental amalgam is more resistant to 😕

a. Compressive stress

b. Tensile stress

c. Shear stress

d. Impact stress

13 / 60

Elgiloy arch wire is 😕

a. β-titanium arch wire

b. Optical fiber arch wire

c. Gold alloy

d. Cobalt-chromium-nickel alloy

14 / 60

The desirable quality of porcelain is 😕

a. Translucency

b. Requirement of color

c. Thermal expansion

d. Toughness without brittleness

15 / 60

Nickel sensitivity in the general population is 😕

a. 11% for women

b. 3% for women

c. 1% in the overall population

d. 3% for men

16 / 60

The most accurate polysulfide impressions are made by using a custom acrylic tray because 😕

a. The tray does not distort during impression making

b. Custom tray made of plastic material ensures a uniform thickness of impression material

c. More pressure can be applied during impression making

d. It can hold more amount of impression material

17 / 60

Main disadvantage of laminate technique of making impression is : ?

a. Cost factor is high

b. Maximum details are not produced

c. Bond between agar and alginate is not very strong

d. Difficult to manipulate

18 / 60

Conventional dental amalgam alloy contains 😕

a. Silver, tin, palladium and zinc

b. Silver, tin, copper and zinc

c. Silver, mercury, copper and zinc

d. Silver, mercury, copper and mercury

19 / 60

A measure of ductility of a material is referred to as 😕

a. Yield strength

b. Proportional limit

c. Percentage elongation

d. Flexibility

20 / 60

One of the following statements which one is incorrect regarding addition silicones 😕

a. Dimensionally stable even after 1 week

b. Can be used in automixing devices

c. Undetectable distortion on removal

d. No evolution of any byproduct under all circumstances

21 / 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

22 / 60

Hand instruments for composites are made of 😕

a. Teflon-coated metal

b. Stainless steel

c. Titanium

d. Carbon steel

23 / 60

Most common use of Zinc oxide eugenol paste 😕

a. As interocclusal record material

b. Surgical paste

c. Dual impression for Partially edentulous patients

d. Wash impression for edentulous patients

24 / 60

Wrought metal 😕

a. Cannot be rendered corrosion resistant

b. Can be formed by pouring molten metal into a mold

c. Cannot be heat treated

d. Can be formed by working on a cast metal

25 / 60

In a porcelain fused to metal restoration, the porcelain is-bonded to metal by 😕

a. High malleafility of metal

b. Chemico-mechenical bonding

c. Chemical bonding

d. Hight ductility of metal

26 / 60

Silver in the set amalgam alloy tends to have the following effect 😕

a. Hydrolyzes the water if contaminated

b. Decreases ductility

c. Decreases the setting time

d. Produces contraction

27 / 60

Which of the following is called periphery wax ?

a. Sticky wax

b. Utility wax

c. Beading wax

d. Bite registration wax

28 / 60

Which of the following sentences describes the construction of removable partial dentures ?

a. They are attached to natural teeth with cements,

b. They are attached to upper natural teeth with cements,

c. They are attached to lower natural teeth with cements,

d. Artificial acrylic teeth are attached

29 / 60

Dental porcelains are manufactured by a process termed as 😕

a. Fritting

b. Fusing

c. Vulcanizing

d. Sintering

30 / 60

Contamination of zinc-containing amalgam by moisture during triturating or condensation :

a. Increases the setting time

b. Results in a sharp decrease in flow

c. Results in a marked expansion

d. Has no appreciable effect on properties except to the susceptibility to tarnish

31 / 60

Bis-GMA is a reaction product of 😕

a. Bis-phenol-A and urethane dimethacrylate

b. Bis-phenol-A and glycidyl methacrylate

c. Bis-phenol-A and methyl methacrylate

d. Urethane dimethacrylate and glycidyl

32 / 60

Thickness of the gel between the tray and tissue for either agar or alginate should always be at least 😕

a. 1 mm

b. 2 mm

c. 4 mm

d. 3 mm

33 / 60

Strength of dental porcelain is dependent on 😕

a. Resistance to fusion

b. Composition

c. Rough

d. No internal structure

34 / 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

35 / 60

In a porcelain fused to metal restoration, when the coefficient of thermal expansion of metal and porcelain are different 😕

a. Porcelain will not bond with metal

b. Porcelain will crack on cooling

c. Porcelain will wear off

d. Porcelain will provide good shade

36 / 60

Which of the following materials are used for dental implants ?

a. Titanium

b. Cobalt and chromium alloys

c. Metal alloys

d. Gold alloys

37 / 60

Which of the following metals currently are used in dental alloys ?

a. Gold

b. Waxe

c. Glass ionomer

d. Ceramic

38 / 60

Condensation of porcelain is done by all the methods except 😕

a. Ceramming method

b. Brush addition technique

c. Spatulation method

d. Vibration method

39 / 60

Potato starch is contained in which impression material ?

a. Potassium sulfate

b. Impression compound

c. Agar agar

d. Impression plaster

40 / 60

Zinc oxide eugenal impression should be removed from oral cavity :

a. When the material cannot be intended by a blunt instrument

b. When the material is glossy

c. Exactly after four minutes after kneading

d. When it can be easily indented by a blunt instrument

41 / 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

42 / 60

Regarding Knoop hardness number, which of the following material is closest to that of dentine (KHN 65) ?

a. Pure gold

b. Silicates

c. Amalgam

d. Composites

43 / 60

Which of the composites with the following fillers may be radiopaque ?

a. Colloidal silica

b. Barium glass

c. Lithium aluminum silicate

d. Quartz

44 / 60

Porosity in denture base resins can be due to 😕

a. Well flasking of wax pattern

b. Applying sufficient pressure during polymerization

c. Excess heating of resin above its boiling point

d. Adequate mixing of liquid and powder components

45 / 60

Softening of impressing compound is best accomplished by 😕

a. Dry heat

b. Oil bath

c. Open flame

d. Water bath

46 / 60

In an alloy oxygen scavenger is 😕

a. Copper

b. Silver

c. Zinc

d. Palladium

47 / 60

Passiveness of chrome cobalt alloys is due to formation of 😕

a. Chromium carbide

b. Cobalt oxide

c. Ferric oxide

d. Chromium oxide

48 / 60

Alginate impression material deteriorates rapidly at 😕

a. Elevated temperature

b. Temperature does not cause any change in shelf-life

c. Low temperature

d. Normal room temperature

49 / 60

In visible light-cured composites photo initiator molecule is 😕

a. Camphoroquinone

b. Bis-phenol-A

c. Benzoyl methyl ether

d. Toluidine

50 / 60

The reason zinc oxide eugenol cement is used as a temporary restoration 😕

a. It does not have anticariogenic activity

b. It has poor tensile strength

c. It does not form reparative dentin

d. It has an obtudant effect

51 / 60

Sulfur contamination from natural latex gloves inhibits the setting of 😕

a. Polyether

b. Alginate

c. Polyvinyl siloxane

d. Zinc oxide eugenol impression paste

52 / 60

The temperature at which a solid changes to liquid is known as its 😕

a. Vapor temperature

b. Temperature of specificity

c. Heat temperature

d. Fusion temperature

53 / 60

All of the following are properties of Co-Cr-Ni wires except 😕

a. Their hardness is comparable to stainless steel

b. They have excellent tarnish and corrosion resistance

c. They can be heat treated

d. They cannot be soldered or welded

54 / 60

Hypersensitivity reactions like contact dermatitis is caused by 😕

a. Condensation silicones

b. Addition silicones

c. Polyether

d. Polysulfides

55 / 60

Which has the highest viscoelastic property and requires more time to recover from deformation ?

a. Polyether

b. Condensation silicone

c. Polysulfide

d. Addition silicone

56 / 60

Calcium hydroxide is used for 😕

a. Reduce maginal leakage

b. Reinforce the restoration

c. To prevent recurrent caries

d. Pulp capping

57 / 60

Ideal metal used for electroplating polysulfide impression is 😕

a. Cobalt

b. Nickel

c. Copper

d. Silver

58 / 60

Which of the following statements about curing of composites are true ?

a. Before light activation, the base and catalyst pastes are mixed.

b. Exposure times of 2 to 3 seconds are needed for polymerization with visible light.

c. Lights with both blue and red wavelengths are equally effective for polymerization.

d. Light from an argon laser will activate polymerization.

59 / 60

Which of the following phases in dental amalgam restoration is most prone to electrochemical properties ?

a. Cu-Sn

b. Ag-Sn

c. Ag-Hg

d. Sn-Hg

60 / 60

Which one of the following phases in dental amalgam restoration has the best mechanical properties ?

a. Cu-Sn

b. Sn-Hg

c. Ag-Hg

d. Ag-Su

Your score is

The average score is 86%

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