Biomaterial Test

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Biomaterial Test

1 / 60

Porcelain denture teeth 😕

a. Have decreased abrasion resistance than dentin

b. Are more resistant of abrasion than gold

c. Have higher coefficient of thermal expansion than resin teeth

d. Are easy to grind and polish

2 / 60

Metal has the following properties except 😕

a. Electroplated silver and copper are used in dies

b. Pure metals are not useful in dentistry

c. Metal is any element that ionizes positively in solution

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

3 / 60

Acrylic resins are used in which of the following ?

a. Anterior onlays

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

c. Denture bases

d. Posterior inlays

4 / 60

In dental plaster the main ingredient is 😕

a. Calcium anhydrate

b. Calcium sulfate hemihydarate

c. Calcium sulfate dehydrate

d. Calcium phosphate

5 / 60

Which of the following occurs when dental amalgam is overmixed ?

a. Corrosion increases

b. Compressive strength decreases

c. Corrosion decreases

d. Tensile strength increases

6 / 60

Dental porcelains are manufactured by a process termed as 😕

a. Fritting

b. Sintering

c. Vulcanizing

d. Fusing

7 / 60

Cobalt-chromium alloy is mostly used for the construction of 😕

a. Transosteal frames

b. Intramucosal frames

c. Endosseus implants

d. Subperiosteal

8 / 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. 30 mg Hg/m3 of air

b. 100 mg Hg/m3 of air

c. 0.05 mg Hg/m3 of air

d. 0.04 mg Hg/m3 of air

9 / 60

Commonly used coloring agent in impression plaster is 😕

a. Metallic oxide

b. Congo red

c. Indigo dye

d. Alizarin red

10 / 60

Cavity varnish should not be applied when the following is used as a filling material 😕

a. Amalgam

b. Direct resin-filling material

c. Zinc phosphate

d. Silicate

11 / 60

The main resin constituent of polishable composite resin is 😕

a. Polycaronate

b. Urethane dimethacrylate

c. Cyanoacrylate

d. Polymethyl methacrylate

12 / 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. fluorite release

d. Floor carpeting

13 / 60

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

a. Paraffin and microcrystalline wax

b. Spermitic and bees wax

c. Montan and Japan coco

d. Carnauba and candellia

14 / 60

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

a. Cured for longer period

b. Fifth generation bonding agent should be applied

c. Restoration should be build in increments

d. Not indicated

15 / 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. Subsequent oxidation of the tertiary amine

c. Increased solubility of the resin

d. Decreased polymerization of the resin

16 / 60

Silver has all the following characteristics except 😕

a. Silver in pure form is not used in dental restorations

b. Whitens when added to alloys

c. Silver points serve as a root canal filling material

d. Addition of palladium to silver increases corrosion

17 / 60

In UV curing system the activator employed is 😕

a. Methyl methacrylate

b. Hydroquinone

c. Benzoin methyl ether

d. Dibutyl phthalate

18 / 60

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

a. Cu-Sn

b. Sn-Hg

c. Ag-Hg

d. Ag-Sn

19 / 60

Ideally, the set amalgam should do which of the following ?

a. Properties of amalgam

b. Expand greatly to provide marginal seal against the tooth

c. Have little dimensional change

d. Shrink significantly to provide space for correction products to seal the margins

20 / 60

Greening effect of porcelain is due to 😕

a. Palladium

b. Platinum

c. Silver

d. Golde

21 / 60

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

a. Brittleness

b. Toughness

c. Hardness

d. Springiness

22 / 60

Spot out incorrect statement regarding zinc in dentistry 😕

a. It is relatively soft and ductile

b. It does not oxidize

c. Pure zinc has no application in dentistry

d. It is low in strength

23 / 60

In dental porcelains metallic oxides provide 😕

a. Provides refractile property and increases strength

b. Color but decreases the strength

c. Color and increases the strength

d. Color and provides refractile property

24 / 60

Which of the following composite is recommended for non stress bearing anterior restoration ?

a. Microfilled composites

b. Small particles

c. Hybrid composites

d. Conventional composites

25 / 60

Ideal metal used for electroplating polysulfide impression is 😕

a. Nickel

b. Silver

c. Copper

d. Cobalt

26 / 60

The byproduct in condensation silicones is 😕

a. Propyl alcohol

b. Methyl alcohol

c. Ethyl alcohol

d. Butyl alcohol

27 / 60

Which of the following composites give rough surfaced finish ?

a. Small particle filled composites

b. Microfilled composites

c. Hybrid composites

d. Conventional composites

28 / 60

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

a. Composite restorative resins

b. Has the toxic properties of unreacted mercury

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

d. Is combined primarily with silver

29 / 60

Setting time of alginate can be better controlled by 😕

a. Chemical accelerators and retarders

b. Changing water: powder ratio

c. Mixing time

d. Temperature of water used of mixing

30 / 60

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

a. Impact stress

b. Shear stress

c. Tensile stress

d. Compressive stress

31 / 60

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

a. 4 mm

b. 1 mm

c. 3 mm

d. 2 mm

32 / 60

The reason for hydroxyapatite coating on implant biomaterials is 😕

a. Lesser bony apposition

b. Greater bony opposition

c. Prolonged healing time

d. Presence of fibrous tissue

33 / 60

The main function of zinc in amalgam is 😕

a. To produce delayed expansion

b. To prevent the creep

c. To increase the shelf-life of an amalgam

d. To increase the longevity of amalgam after setting

34 / 60

Commonly used filler in composite is 😕

a. Glass

b. Quartz

c. Colloidal silica

d. Aluminum

35 / 60

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

a. Silicate cement

b. Unfilled acrylic resin

c. Glass ionomer cement

d. Composite resin

36 / 60

Working time of denture resin should be at least 😕

a. 15 minutes

b. 20 minutes

c. 10 minutes

d. 5 minutes

37 / 60

In an alloy oxygen scavenger is 😕

a. Zinc

b. Palladium

c. Silver

d. Copper

38 / 60

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

a. Toughness

b. Modulus of elasticity

c. Resilience

d. Flexibility

39 / 60

Binder in the phosphate investment is 😕

a. Phosphoric acid

b. Magnesium oxide and monoammonium phosphate

c. Cristobalite

d. Manganese dioxide

40 / 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

41 / 60

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

a. Gypsum

b. Water

c. Silica

d. Quartz

42 / 60

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

a. increase strength

b. Reduce porosity

c. Reduce firing shrinkage

d. Reduce brittleness

43 / 60

The main advantage of composites compared to silicates cement is 😕

a. High modulus of resilience

b. Practically insoluble in oral fluids

c. Color matching with the tooth structure is excellent

d. Coefficient of thermal expansion close to tooth structure

44 / 60

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

a. It has not more working time available

b. It takes more time for curing

c. It has more working time available

d. It is more sensitive to oxygen inhibitors

45 / 60

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

a. Flexibility

b. Yield strength

c. Proportional limit

d. Percentage elongation

46 / 60

Softening of impressing compound is best accomplished by 😕

a. Oil bath

b. Open flame

c. Dry heat

d. Water bath

47 / 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

48 / 60

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

a. Carbide burs at high speed

b. Carbide burs at low to medium speed

c. Diamond burs at low to medium speed

d. Diamond burs at high speed

49 / 60

The cracks formed on the ceramic during cooling because 😕

a. The cooling of the outer and the inner layer occurs at the same rate

b. Due to external forces

c. The outer layer cools more rapidly than the interior

d. The inner layer cools more rapidly than the outer layer

50 / 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. Radiopaque

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

d. They are radiolucent.

51 / 60

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

a. Cu-Sn

b. Sn-Hg

c. Ag-Su

d. Ag-Hg

52 / 60

Main disadvantage of denture base soft reliner is 😕

a. It can be cleaned properly

b. It can not lead to cleaned property

c. It has not to be changed over a period of time

d. It can not lead to fungal growth

53 / 60

Impression compound is characterized by 😕

a. Amorphous in nature with low thermal conductivity

b. Crystalline in nature with high thermal conductivity

c. Amorphous in nature with high thermal conductivity

d. Crystalline in nature with definite melting point

54 / 60

In deep caities, the resin which remains unpolymerized can cause 😕

a. Pulp inflammation

b. Sagging of restoration

c. Porosity in restoration

d. Secondary caries

55 / 60

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

a. Feldspar

b. Silica

c. Kaolin

d. Potash

56 / 60

Commonly used viscosity controller in composites is 😕

a. Polyurethanes

b. TEG-DMA

c. Methyl methacrylate

d. Bis-GAM

57 / 60

The maximum warpage of acrylic denture occurs during 😕

a. Polishing

b. Curing

c. Packing

d. Deflasking

58 / 60

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

a. Ag-Hg

b. Ag-Sn

c. Sn-Hg

d. Cu-Sn

59 / 60

Gold casting alloys are classified as type I, II, III or IV among these, having highest hardness is 😕

a. Type IV

b. Type III

c. Type II

d. Type I

60 / 60

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

a. Iatrogenesis

b. Teratogenesis

c. Biocompatibility

d. Carcinogenesis

Your score is

The average score is 22%

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