Biomaterial Test

5 votes, 5 avg

164

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Biomaterial Test

1 / 60

Glass ionomer cenment is not recommended for 😕

a. Class I restoration

b. Class III restoration

c. Class V restoration

d. Class IV resoration

2 / 60

Thermal conductivity is proportional to 😕

a. Hardness of metal

b. Fusion temperature

c. Area of conduction

d. Type of metal

3 / 60

The fluoride release from glass ionomer cement is 😕

a. 0.075 mg during the first month

b. 0.0005 mg during the first month

c. 0.75 mg during the first week

d. 0.005 mg during the first week

4 / 60

Adhesion in composites is due to 😕

a. Cohesion

b. Mechanical interlocking

c. Presence of smear layer

d. True chemical bonding to tooth structure

5 / 60

Side effects and complications resulting from treatment by a physician or dentist is 😕

a. Carcinogenesis

b. Biocompatibility

c. Teratogenesis

d. Iatrogenesis

6 / 60

Proconditioning before GIC restoration is done in order to 😕

a. Remove smear layer

b. Create tags

c. Facilitate mechanical bonding

d. Provide more strenght

7 / 60

Passiveness of chrome cobalt alloys is due to formation of 😕

a. Cobalt oxide

b. Ferric oxide

c. Chromium carbide

d. Chromium oxide

8 / 60

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

a. They have excellent tarnish and corrosion resistance

b. Their hardness is comparable to stainless steel

c. They can be heat treated

d. They cannot be soldered or welded

9 / 60

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

a. Adhesion

b. Biocompatibility

c. Flow

d. Dimensional stability

10 / 60

Softening of impressing compound is best accomplished by 😕

a. Oil bath

b. Open flame

c. Water bath

d. Dry heat

11 / 60

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

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

b. They are attached to natural teeth with cements,

c. Artificial acrylic teeth are attached

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

12 / 60

Commonly used viscosity controller in composites is 😕

a. TEG-DMA

b. Bis-GAM

c. Polyurethanes

d. Methyl methacrylate

13 / 60

Gypsum investments should not be heated above 😕

a. 10000C

b. 4500C

c. 17000C

d. 7000C

14 / 60

Porosity in denture base resins can be due to 😕

a. Excess heating of resin above its boiling point

b. Applying sufficient pressure during polymerization

c. Well flasking of wax pattern

d. Adequate mixing of liquid and powder components

15 / 60

Which of the following statements about laboratory composites are true ?

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

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

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

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

16 / 60

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

a. Barium glass

b. Quartz

c. Lithium aluminum silicate

d. Colloidal silica

17 / 60

A glaze is placed over the finished composite restoration to 😕

a. To change the shade

b. No provide a better peripheral seal

c. To reduce surface porosities

d. Create a rough surface that is less receptive to extrinsic stain and plaque retention

18 / 60

The greatest amount of dimensional change after setting is exhibited by 😕

a. Polyethers

b. Polysulfides

c. Condensation silicones

d. Addition silicones

19 / 60

The main use of zinc oxide eugenol cement is 😕

a. Indirect pulp capping agent

b. Base

c. Temporary restoration

d. Permanent restoration

20 / 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

21 / 60

Crystalline materials have 😕

a. No well-defined melting

b. No space lattice

c. Well-defined melting

d. Less stable space lattice

22 / 60

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

a. Strain

b. Stress

c. Space lattice

d. Amorphous material

23 / 60

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

a. Diamond burs at low to medium speed

b. Carbide burs at high speed

c. Carbide burs at low to medium speed

d. Diamond burs at high speed

24 / 60

Porcelain-bonded to metal is stronger when fired 😕

a. Under compression

b. After metal is tempered

c. Under low temperature

d. Several times in air

25 / 60

Of the four types of gold casting alloys, the most commonly used for crowns and bridges is 😕

a. Type I

b. Type II

c. Type IV

d. Type III

26 / 60

The most commonly used implant type presently is 😕

a. Subperiosteal

b. Transosteal implant

c. Intramucosal implant

d. Endosseous

27 / 60

Which of the following is a measure of resistance to fracture ?:

a. Springiness

b. Brittleness

c. Toughness

d. Hardness

28 / 60

Compared to lathe-cut alloy, spherical dental amalgam alloys 😕

a. Have longer setting time

b. Requires higher forces of condensation

c. Requires less amalgamation time

d. Requires more mercury for trituration

29 / 60

Amalgam is less prone to corrosion 😕

a. If it contains 25-27% of tin

b. If it contains zinc

c. If it contains 4-6% of copper

d. If devoid of the gamma 2 phase

30 / 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 removable and attached to teeth with clasps.

c. Artificial waxes teeth are attached

d. Carbone steal

31 / 60

A cavity varnish used for lining the preparation for a dental amalgam restoration will :

a. Provide electrical insulation

b. Reduce early marginal leakage tooth structure

c. Provide thermal insulation

d. Provide strength of amalgam

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

In alginate impression the final gel is 😕

a. Sodium sulphate

b. Calcium sulphate

c. Sodium alginate

d. Calcium alginate

34 / 60

The common characteristic for pit and fissure sealant composite resins, acrylic appliances and elastomeric impression materials is :

a. All of them can be employed as anterior filling materials

b. All of them are polymers

c. All of them are a result of secondary reaction

d. All of them should be heated before using

35 / 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. Low strength, low creep, low corrosion

d. Higher strength, high creep, high corrosion

36 / 60

Nickel sensitivity in the general population is 😕

a. 3% for women

b. 1% in the overall population

c. 3% for men

d. 11% for women

37 / 60

The cavity for a GIC restoration is preconditioned with 😕

a. Phosphoric acid for 10 seconds

b. Polyacrylic acid for 60 seconds

c. Polyacrylic acid for 10 seconds

d. Phosphoric acid for 60 seconds

38 / 60

Zinc oxide eugenal impression should be removed from oral cavity :

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

b. When the material is glossy

c. Exactly after four minutes after kneading

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

39 / 60

Dental porcelains are manufactured by a process termed as 😕

a. Sintering

b. Fusing

c. Fritting

d. Vulcanizing

40 / 60

Wrought metal 😕

a. Cannot be heat treated

b. Cannot be rendered corrosion resistant

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

d. Can be formed by working on a cast metal

41 / 60

Which of the following properties of calcium hydroxide cement help in the formation of reparative dentin ?

a. Low alkalinity

b. No antibacterial action

c. No Protein lysing effect

d. High alkalinity

42 / 60

Color stability of cold-cured resins is inferior to that of heat cured resins due to 😕

a. Subsequent oxidation of the tertiary amine

b. Increased solubility of the resin

c. Variation in the molecular weight of the resin (low mol wt)

d. Decreased polymerization of the resin

43 / 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

44 / 60

Dispensing composite resins using a syringe is advantageous because it 😕

a. Conserves the material

b. Increases surface smoothness

c. Increases strength and abrasive resistance

d. Decreases air voids in the restoration

45 / 60

Main disadvantage of laminate technique of making impression is : ?

a. Bond between agar and alginate is not very strong

b. Maximum details are not produced

c. Cost factor is high

d. Difficult to manipulate

46 / 60

Montan waxes have the following properties except 😕

a. Hard, brittle and lustrous

b. Obtained by extraction from lignite

c. Are mineral waxes

d. Have low melting points of 42oC

47 / 60

Polyether is different from other elastomers in the following aspects 😕

a. Low stiffness

b. High stiffiness

c. Hydropholic in nature

d. Can not be used as light cure material

48 / 60

Following are the functions of impression compound except 😕

a. To make individual die impression with copper band

b. To make special tray for final impression

c. To record mucostatic impressions

d. To make impression of edentulous ridge

49 / 60

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

a. Glass ionomer cement

b. Unfilled

c. Silicate cement

d. Amalgam

50 / 60

Noble metal alloys are classified according to their 😕

a. Malleability

b. Melting temperature

c. Dental function

d. Castability

51 / 60

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

a. Proportional limit

b. Yield strength

c. Percentage elongation

d. Flexibility

52 / 60

Which of the following initiator-accelerator systems is needed for a light-activated composite?

a. Organic acid-metal ion

b. Organic acid-peroxide

c. Diketone-amine

d. Peroxide-amine

53 / 60

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

a. Porcelain will crack on cooling

b. Porcelain will provide good shade

c. Porcelain will wear off

d. Porcelain will not bond with metal

54 / 60

A portion of a posterior tooth that is subject to high biting forces would likely be restored with which of the following ?

a. Glass ionomer

b. Amalgam

c. Composite resin

d. Acrylic resin

55 / 60

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

a. Sn-Hg

b. Cu-Sn

c. Ag-Hg

d. Ag-Sn

56 / 60

One of the following statements which one is incorrect regarding polyether :

a. The main chain consists of copolymer of methylene oxide and tetrahydrofuran

b. The base paste consists of polyether polymer

c. The main chain of polyether consists of copolymer of ethylene oxide and tetrahydrofuran

d. Aromatic sulfonate ester acts as a cross linking agent

57 / 60

Strain that occurs when the material is stressed to its proportional limit is called 😕

a. Modulus of elasticity

b. Resilience

c. Toughness

d. Flexibility

58 / 60

The following statements about dental porcelains are true except 😕

a. Undergoes firing shrinkage

b. Undergoes discoloration

c. It is brittle in nature

d. Crystalline nature

59 / 60

Alginate impression material deteriorates rapidly at 😕

a. Low temperature

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

c. Normal room temperature

d. Elevated temperature

60 / 60

Impression plaster is a 😕

a. Mucostatic material

b. Mucocompressive material

c. Reversible impression material

d. Thermoplastic material

Your score is

The average score is 86%

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