Biomaterial Test

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Biomaterial Test

1 / 60

Crystal structures of metals are all the following except 😕

a. Tetragonal

b. Circular

c. Monoclinic

d. Cubic

2 / 60

The impression material which is routinely used in auto mixing devicee system is 😕

a. Condensation silicone

b. Polyvinyl siloxane

c. Polysulfied

d. Polyether

3 / 60

Materials having coefficient of thermal expansion close to the tooth structure 😕

a. Amalgam

b. Glass ionomer cement

c. Silicate cement

d. Unfilled

4 / 60

Which of the following properties would be of least importance, when selecting an impression material ?

a. Adhesion

b. Dimensional stability

c. Biocompatibility

d. Flow

5 / 60

The chemistry behind the condensation of the amalgam is to 😕

a. To reduce gamma II particules

b. Condense the unattacked gamma particles

c. Condense the unattacked gamma II particles

d. Condense the unattacked gamma I particles

6 / 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. Tensile strength spherical high-copper

c. 1-hour compressive strength spherical high-copper

d. Creep irregular high-copper

7 / 60

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

a. Has a better reaction with zinc oxide

b. To increase setting time

c. Reduces burning sensation of paste

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

8 / 60

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

a. Sn-Hg

b. Ag-Sn

c. Ag-Hg

d. Cu-Sn

9 / 60

Porcelain denture teeth 😕

a. Are easy to grind and polish

b. Have higher coefficient of thermal expansion than resin teeth

c. Are more resistant of abrasion than gold

d. Have decreased abrasion resistance than dentin

10 / 60

In an alloy oxygen scavenger is 😕

a. Palladium

b. Silver

c. Zinc

d. Copper

11 / 60

Which of these statements apply to the filler particles of composites ?

a. All are correct

b. Microfilled composites contain more filler than all-purpose composites.

c. Microhybrid composites contain as much as 84% filler by weight.

d. Microfilled

12 / 60

The primary difference between low- and high-copper amalgams is which of the following ?

a. The amount of copper

b. The amount of copper and zinc

c. The amount of copper and tin

d. The amount of copper and silver

13 / 60

Wet porcelain is condensed properly before firing to enhance all the properties except : ?

a. Reduce firing shrinkage

b. Reduce brittleness

c. Reduce porosity

d. increase strength

14 / 60

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

a. Hydrolyzes the water if contaminated

b. Decreases the setting time

c. Produces contraction

d. Decreases ductility

15 / 60

Full denture bases are usually made from which of the following materials ?

a. Acrylic resin

b. Composite restorative resins

c. Ceramic

d. Gold alloys

16 / 60

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

a. Polysulfide

b. Polyether

c. Condensation silicone

d. Addition silicone

17 / 60

Commonly used filler in composite is 😕

a. Colloidal silica

b. Quartz

c. Glass

d. Aluminum

18 / 60

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

a. Ag-Hg

b. Sn-Hg

c. Ag-Su

d. Cu-Sn

19 / 60

In the cavities which are more than 2mm deep a light-cured restoration is 😕

a. Fifth generation bonding agent should be applied

b. Not indicated

c. Cured for longer period

d. Restoration should be build in increments

20 / 60

Which of the following statements apply to the packable composites ?

a. Their depth of cure allows bulk polymerization, which has been shown to be clinically effective.

b. Their wear rate is low (3.5 μm/year). Which is similar to that of amalgam.

c. They are radiolucent.

d. Radiopaque

21 / 60

Which one of the following office conditions minimize the health hazard from spilled mercury ?

a. Baseboard heating

b. Amalgam scrap stored in a closed container

c. Floor carpeting

d. fluorite release

22 / 60

Light source in the curing unit is usually 😕

a. Infra red bulb

b. Sun light

c. Tungsten halogen light bulb

d. Ultraviolet light bulb

23 / 60

The light-cured restorative resins have advantages over chemically activated restorative resins as 😕

a. It is more sensitive to oxygen inhibitors

b. It takes more time for curing

c. It has not more working time available

d. It has more working time available

24 / 60

Which of the following statements is true regarding zinc phosphate cement ?

a. Has an obtudant effect on the pulp

b. The least irritant to the pulp

c. Is used as a permanent restorative material in adults

d. Is the oldest luting agent

25 / 60

Condensation of porcelain is done by all the methods except 😕

a. Vibration method

b. Spatulation method

c. Brush addition technique

d. Ceramming method

26 / 60

Working time of denture resin should be at least 😕

a. 5 minutes

b. 10 minutes

c. 20 minutes

d. 15 minutes

27 / 60

Which of the following composites give rough surfaced finish ?

a. Conventional composites

b. Hybrid composites

c. Microfilled composites

d. Small particle filled composites

28 / 60

Softening of impressing compound is best accomplished by 😕

a. Open flame

b. Dry heat

c. Water bath

d. Oil bath

29 / 60

The main resin constituent of polishable composite resin is 😕

a. Polycaronate

b. Cyanoacrylate

c. Polymethyl methacrylate

d. Urethane dimethacrylate

30 / 60

Which of the following occurs when dental amalgam is overmixed ?

a. Corrosion decreases

b. Corrosion increases

c. Tensile strength increases

d. Compressive strength decreases

31 / 60

The function of gum dammar in inlay wax is 😕

a. To improve smoothness of pattern

b. Less strength to wax

c. No resistance to carving

d. No smoothness of pattern

32 / 60

Pick out the incorrect statement regarding alginate impressions 😕

a. Will take up water and expand if kept wet

b. Will be shrink as a result of syneresis

c. Is an irreversible hydrocolloid impression material

d. May exhibit a fluid exudates on the surface as a result of imbibitions

33 / 60

Spot out incorrect statement regarding zinc in dentistry 😕

a. It does not oxidize

b. Pure zinc has no application in dentistry

c. It is low in strength

d. It is relatively soft and ductile

34 / 60

The physical properties most desirable in set amalgam are which of the following ?

a. Higher strength, high creep, low corrosion

b. Higher strength, low creep, low corrosion

c. Higher strength, high creep, high corrosion

d. Low strength, low creep, low corrosion

35 / 60

An anterior fixed partial denture could have facings constructed of which of the following materials ?

a. Silver alloys

b. Gold alloy

c. Amalgam

d. Ceramic

36 / 60

Which of the following components acts as a refractory material in porcelain ?

a. Feldspar

b. Kaolin

c. Potash

d. Silica

37 / 60

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

a. Artificial acrylic teeth are attached

b. They are attached to natural teeth with cements,

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

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

38 / 60

Excess composite from the labial surfaces can be removed by using 😕

a. Carbide burs at low to medium speed

b. Diamond burs at low to medium speed

c. Carbide burs at high speed

d. Diamond burs at high speed

39 / 60

The gelation temperature of agar hydrocolloid impression material should be 😕

a. 100C higher than mouth temperature

b. Far below the oral temperature

c. 45-600C

d. 37-450C

40 / 60

The physical property measured in terms of the deformation of the structure per until dimensions is ?

a. Space lattice

b. Amorphous material

c. Strain

d. Stress

41 / 60

Stearic acid in impression compound 😕

a. Reduces flow

b. Increase setting time

c. Reduces plasticity

d. Reduces brittleness

42 / 60

Which of the following waxes is obtained from distillation of petroleum ?

a. Paraffin and microcrystalline wax

b. Carnauba and candellia

c. Montan and Japan coco

d. Spermitic and bees wax

43 / 60

Which of the following statements about laboratory composites are true ?

a. Restorations prepared from laboratory composites typically are cemented with zinc phosphate cement.

b. Curing using light, heat, and pressure increase the wear resistance.

c. Bridge prepared from laboratory composites require a metal substructure.

d. Fiber reinforcement increases their strength but decrease their rigidity.

44 / 60

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

a. Composite

b. Compomer

c. Hybrid ionomer

d. Glass ionomer

45 / 60

Which of the following statements is incorrect regarding hydroxyapatite as an implant material ?

a. It is a bio-inert material

b. This material in granular form and is difficult

c. It is produced in block or granula form

d. It is used for augmenting alveolar ridges of filling bony defects

46 / 60

Main disadvantage of laminate technique of making impression is : ?

a. Bond between agar and alginate is not very strong

b. Cost factor is high

c. Maximum details are not produced

d. Difficult to manipulate

47 / 60

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

a. Proportional limit

b. Flexibility

c. Percentage elongation

d. Yield strength

48 / 60

Setting of plaster of Paris is a result of 😕

a. Interaction between hemihydrates and water

b. Indirect interaction between hemihydrates

c. Loss of water from hemihydrates

d. Solubility difference between hemihydrates and dehydrate

49 / 60

Following are the functions of impression compound except 😕

a. To make special tray for final impression

b. To make individual die impression with copper band

c. To record mucostatic impressions

d. To make impression of edentulous ridge

50 / 60

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

a. Heat temperature

b. Fusion temperature

c. Temperature of specificity

d. Vapor temperature

51 / 60

Hypersensitivity reactions like contact dermatitis is caused by 😕

a. Polysulfides

b. Condensation silicones

c. Polyether

d. Addition silicones

52 / 60

Minimal thickness of base for adequate thermal insulation is 😕

a. 0.5 mm

b. 0.75 mm

c. 2 mm

d. 1 mm

53 / 60

In visible light-cured composites photo initiator molecule is 😕

a. Benzoyl methyl ether

b. Camphoroquinone

c. Bis-phenol-A

d. Toluidine

54 / 60

Proconditioning before GIC restoration is done in order to 😕

a. Facilitate mechanical bonding

b. Remove smear layer

c. Create tags

d. Provide more strenght

55 / 60

Which of the following office conditions minimize the health hazard from spilled mercury ?

a. Floor carpeting

b. Baseboard heating

c. Wall carpeting

d. Amalgam scrap stored in a closed container

56 / 60

Greening effect of porcelain is due to 😕

a. Golde

b. Silver

c. Palladium

d. Platinum

57 / 60

Nickel in base metal alloys increase its 😕

a. Hardness and fusion temperature

b. S Ductility

c. Strength

d. Modulus of elasticity

58 / 60

The most commonly employed alloy combination for use in implants is 😕

a. Titanium-platinum-aluminum alloy

b. Titanium-molybdenum-vanadium alloy

c. Platinum-aluminum-vanadium alloy

d. Titanium-aluminum-vanadium alloy

59 / 60

Commonly used coloring agent in impression plaster is 😕

a. Metallic oxide

b. Alizarin red

c. Congo red

d. Indigo dye

60 / 60

The light from the visible light curing unit can cause 😕

a. Corneal ulceration

b. Cataract

c. Iritis

d. Retinal damage

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