Biomaterial Test

5 votes, 5 avg

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Biomaterial Test

1 / 60

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

a. Polyethers

b. Addition silicones

c. Condensation silicones

d. Polysulfides

2 / 60

Greater ratio fo zinc oxide to eugenol will have the following effect on setting time 😕

a. Increases setting time

b. Decreases setting time

c. Depends on rate of mixing

d. Does not alter setting time

3 / 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

4 / 60

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

a. Ceramic

b. Waxe

c. Glass ionomer

d. Gold

5 / 60

Crystal structures of metals are all the following except 😕

a. Monoclinic

b. Tetragonal

c. Circular

d. Cubic

6 / 60

Nickel sensitivity in the general population is 😕

a. 3% for men

b. 1% in the overall population

c. 11% for women

d. 3% for women

7 / 60

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

a. Gold alloy

b. Amalgam

c. Composite resin

d. Metal

8 / 60

Which of the following statements about compomers are true ?

a. Because of their resin content, they require a bonding agent for adhesion to tooth structure.

b. They also are know as GIC

c. They typically are recommended for class II restorations.

d. They are two-paste systems that self-cure within 2 to 3 minutes.

9 / 60

Commonly used filler in composite is 😕

a. Aluminum

b. Glass

c. Colloidal silica

d. Quartz

10 / 60

Following are the functions of impression compound except 😕

a. To make individual die impression with copper band

b. To record mucostatic impressions

c. To make special tray for final impression

d. To make impression of edentulous ridge

11 / 60

Which of the following polymer systems are used for the organic matrix in composites ?

a. Poly (methyl methacrylate)

b. Bisphenol A-glycidyl methacrylate (Bis-GMA)

c. Pheyl methacrylate

d. Polystyrene

12 / 60

Which of the following waxes used to align of castings before soldering ?

a. Carding wax

b. Base plate wax

c. Sticky wax

d. Utility wax

13 / 60

Light source in the curing unit is usually 😕

a. Infra red bulb

b. Tungsten halogen light bulb

c. Ultraviolet light bulb

d. Sun light

14 / 60

In UV curing system the activator employed is 😕

a. Hydroquinone

b. Dibutyl phthalate

c. Benzoin methyl ether

d. Methyl methacrylate

15 / 60

Which of the following material has a high coefficient of thermal expansion ?

a. Silicate cement

b. Unfilled acrylic resin

c. Composite resin

d. Glass ionomer cement

16 / 60

Noble metal alloys are classified according to their 😕

a. Dental function

b. Malleability

c. Castability

d. Melting temperature

17 / 60

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

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

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

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

d. Light from an argon laser will activate polymerization.

18 / 60

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

a. Porcelain will wear off

b. Porcelain will not bond with metal

c. Porcelain will crack on cooling

d. Porcelain will provide good shade

19 / 60

The maximum warpage of acrylic denture occurs during 😕

a. Deflasking

b. Curing

c. Packing

d. Polishing

20 / 60

Commonly used viscosity controller in composites is 😕

a. Methyl methacrylate

b. Bis-GAM

c. TEG-DMA

d. Polyurethanes

21 / 60

Impression plaster is a 😕

a. Thermoplastic material

b. Reversible impression material

c. Mucostatic material

d. Mucocompressive material

22 / 60

The fluoride release from glass ionomer cement is 😕

a. 0.075 mg during the first month

b. 0.75 mg during the first week

c. 0.005 mg during the first week

d. 0.0005 mg during the first month

23 / 60

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

a. Space lattice

b. Strain

c. Stress

d. Amorphous material

24 / 60

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

a. Gold alloy

b. Porcelain

c. Composite resin

d. Amalgam

25 / 60

The cavity for a GIC restoration is preconditioned with 😕

a. Phosphoric acid for 60 seconds

b. Phosphoric acid for 10 seconds

c. Polyacrylic acid for 60 seconds

d. Polyacrylic acid for 10 seconds

26 / 60

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

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

b. Increased solubility of the resin

c. Subsequent oxidation of the tertiary amine

d. Decreased polymerization of the resin

27 / 60

Elgiloy arch wire is 😕

a. Optical fiber arch wire

b. Gold alloy

c. β-titanium arch wire

d. Cobalt-chromium-nickel alloy

28 / 60

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

a. Carnauba and candellia

b. Paraffin and microcrystalline wax

c. Spermitic and bees wax

d. Montan and Japan coco

29 / 60

Thermal conductivity is proportional to 😕

a. Fusion temperature

b. Area of conduction

c. Hardness of metal

d. Type of metal

30 / 60

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

a. Condensation silicone

b. Addition silicone

c. Polysulfide

d. Polyether

31 / 60

The main resin constituent of polishable composite resin is 😕

a. Cyanoacrylate

b. Urethane dimethacrylate

c. Polycaronate

d. Polymethyl methacrylate

32 / 60

Setting of plaster of Paris is a result of 😕

a. Indirect interaction between hemihydrates

b. Loss of water from hemihydrates

c. Interaction between hemihydrates and water

d. Solubility difference between hemihydrates and dehydrate

33 / 60

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

a. Type III

b. Type IV

c. Type I

d. Type II

34 / 60

A glaze is placed over the finished composite restoration to 😕

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

b. To change the shade

c. To reduce surface porosities

d. No provide a better peripheral seal

35 / 60

Proportional limit is defined as :

a. The stress/strain ratio within the elastic limit in a structure

b. The maximum force required to cause a structure to break

c. The maximum stress that can be induced without permanent deformation

d. A deformation resulting from an applied load

36 / 60

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

a. Water

b. Gypsum

c. Quartz

d. Silica

37 / 60

Once amalgamation has occurred, which of the following is true of mercury ?

a. Has the toxic properties of unreacted mercury

b. Composite restorative resins

c. Is combined primarily with silver

d. Can form at the surface of amalgam restorations if heated to 0° C

38 / 60

Ideal metal used for electroplating polysulfide impression is 😕

a. Nickel

b. Copper

c. Cobalt

d. Silver

39 / 60

Binder in the phosphate investment is 😕

a. Cristobalite

b. Phosphoric acid

c. Magnesium oxide and monoammonium phosphate

d. Manganese dioxide

40 / 60

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

a. Reduces burning sensation of paste

b. Has a better reaction with zinc oxide

c. To increase setting time

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

41 / 60

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

a. They can be heat treated

b. They have excellent tarnish and corrosion resistance

c. They cannot be soldered or welded

d. Their hardness is comparable to stainless steel

42 / 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. Micrographs of alloys particles.

c. Wear facets along the occlusal contach areas

d. Marginal ditching along occlusal margins

43 / 60

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

a. Teratogenesis

b. Carcinogenesis

c. Iatrogenesis

d. Biocompatibility

44 / 60

Which one of the following represents the maximum safe concentration of mercury vapor in the breathing zone for a 40-hour work week ?

a. 0.05 mg Hg/m3 of air

b. 30 mg Hg/m3 of air

c. 100 mg Hg/m3 of air

d. 0.04 mg Hg/m3 of air

45 / 60

The byproduct in condensation silicones is 😕

a. Ethyl alcohol

b. Methyl alcohol

c. Butyl alcohol

d. Propyl alcohol

46 / 60

One of the disadvantages of using quartz as filler in restorative resin is 😕

a. It cannot be polished

b. It cannot be reduced to the size of microparticle composite

c. It cause abrasion and wearing of opposing tooth surface

d. It has low affinity for resin matrix

47 / 60

Which of the following uses a hardened steel ball indenting tool ?

a. Vichers hardness test

b. Brinell hardness test

c. Knoop hardness test

d. Rockwell hardness test

48 / 60

Metal has the following properties except 😕

a. Metal is any element that ionizes positively in solution

b. Pure metals are not useful in dentistry

c. All metals do not have same degrees of strength and plasticity

d. Electroplated silver and copper are used in dies

49 / 60

Gypsum investments should not be heated above 😕

a. 4500C

b. 10000C

c. 17000C

d. 7000C

50 / 60

The most effective cement in stimulating tertiary dentin is 😕

a. Zinc silicophoshpate

b. Zinc phosphate

c. Calcum hydroxide

d. Polycardoxylate

51 / 60

Which of the following elastomers is suited for multiple cast pouring 😕

a. Polysulfide

b. Polyether

c. Condensation silicone

d. Addition silicone

52 / 60

Greening effect of porcelain is due to 😕

a. Palladium

b. Platinum

c. Golde

d. Silver

53 / 60

Setting time of alginate can be better controlled by 😕

a. Mixing time

b. Chemical accelerators and retarders

c. Changing water: powder ratio

d. Temperature of water used of mixing

54 / 60

Which of the following properties are higher for microhybrid composites than for microfilled composites ?

a. Water sorption

b. Thermal expansion

c. Modulus of elasticity

d. Polymerization shrinkage

55 / 60

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

a. Feldspar

b. Silica

c. Potash

d. Kaolin

56 / 60

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

a. All are correct

b. Microfilled

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

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

57 / 60

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

a. Not indicated

b. Fifth generation bonding agent should be applied

c. Cured for longer period

d. Restoration should be build in increments

58 / 60

The chemistry behind the condensation of the amalgam is to 😕

a. Condense the unattacked gamma I particles

b. Condense the unattacked gamma II particles

c. To reduce gamma II particules

d. Condense the unattacked gamma particles

59 / 60

Oxalates, carbonates, potassium, trisodium phosphates are added to alginate as 😕

a. Accelerators

b. Retarders

c. Fillers

d. Reactors

60 / 60

If the light cure resin is curd in increments, it helps in 😕

a. Compensating polymerization shrinkage

b. Saving the application of bonding agent

c. Achieving complete polymerization

d. Providing strength to the restoration

Your score is

The average score is 86%

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