Biomaterial Test

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Biomaterial Test

1 / 60

Condensation of porcelain is done by all the methods except 😕

a. Spatulation method

b. Brush addition technique

c. Ceramming method

d. Vibration method

2 / 60

Spot out incorrect statement regarding zinc in dentistry 😕

a. It does not oxidize

b. It is low in strength

c. It is relatively soft and ductile

d. Pure zinc has no application in dentistry

3 / 60

Light source in the curing unit is usually 😕

a. Sun light

b. Infra red bulb

c. Tungsten halogen light bulb

d. Ultraviolet light bulb

4 / 60

The main resin constituent of polishable composite resin is 😕

a. Polymethyl methacrylate

b. Cyanoacrylate

c. Polycaronate

d. Urethane dimethacrylate

5 / 60

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

a. Temperature of specificity

b. Fusion temperature

c. Heat temperature

d. Vapor temperature

6 / 60

The reason for hydroxyapatite coating on implant biomaterials is 😕

a. Prolonged healing time

b. Lesser bony apposition

c. Presence of fibrous tissue

d. Greater bony opposition

7 / 60

Crystal structures of metals are all the following except 😕

a. Monoclinic

b. Tetragonal

c. Cubic

d. Circular

8 / 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

9 / 60

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

a. Does not alter setting time

b. Depends on rate of mixing

c. Increases setting time

d. Decreases setting time

10 / 60

Binder in the phosphate investment is 😕

a. Phosphoric acid

b. Cristobalite

c. Magnesium oxide and monoammonium phosphate

d. Manganese dioxide

11 / 60

Passiveness of chrome cobalt alloys is due to formation of 😕

a. Cobalt oxide

b. Ferric oxide

c. Chromium carbide

d. Chromium oxide

12 / 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 provide good shade

c. Porcelain will wear off

d. Porcelain will crack on cooling

13 / 60

When a mechanical device is used for mixing addition silicones 😕

a. There is no greater uniformity in proportioning and mixing

b. Mixing time is reduced

c. Mixing time is long

d. More possibilities of contamination

14 / 60

In an alloy oxygen scavenger is 😕

a. Silver

b. Copper

c. Palladium

d. Zinc

15 / 60

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

a. Stress

b. Strain

c. Space lattice

d. Amorphous material

16 / 60

Nickel sensitivity in the general population is 😕

a. 3% for women

b. 3% for men

c. 1% in the overall population

d. 11% for women

17 / 60

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

a. Pheyl methacrylate

b. Polystyrene

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

d. Poly (methyl methacrylate)

18 / 60

Hydrocolloid impression should be removed from the mouth with a sharp jerk because 😕

a. The brush heap structure of a gel responds more favorably to a sudden force

b. It decreases the time for syneresis to occur

c. Faster rate of removal increases the yield strength

d. It is the easiest method of removal

19 / 60

The tendency of stainless steel to break under repeated condition of cyclic stressing below the ultimate strength is 😕

a. Ductility

b. Fatigue

c. Resilience

d. Creep

20 / 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

21 / 60

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

a. 3 mm

b. 2 mm

c. 4 mm

d. 1 mm

22 / 60

Which of the following statements about compomers are true ?

a. They typically are recommended for class II restorations.

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

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

d. They also are know as GIC

23 / 60

In UV curing system the activator employed is 😕

a. Dibutyl phthalate

b. Benzoin methyl ether

c. Methyl methacrylate

d. Hydroquinone

24 / 60

Which of the following base is contraindicated for composites ?

a. Zinc oxide eugenol

b. Zinc phosphate

c. Glass ionomer cement

d. Calcium hydroxide

25 / 60

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

a. Brinell hardness test

b. Vichers hardness test

c. Rockwell hardness test

d. Knoop hardness test

26 / 60

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

a. Silicate

b. Amalgam

c. Direct resin-filling material

d. Zinc phosphate

27 / 60

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

a. Requires more mercury for trituration

b. Requires higher forces of condensation

c. Have longer setting time

d. Requires less amalgamation time

28 / 60

Porcelain-bonded to metal is stronger when fired 😕

a. Several times in air

b. Under low temperature

c. After metal is tempered

d. Under compression

29 / 60

Which of the following materials are used for dental implants ?

a. Metal alloys

b. Titanium

c. Gold alloys

d. Cobalt and chromium alloys

30 / 60

Acrylic resins are used in which of the following ?

a. Denture bases

b. Anterior onlays

c. Posterior inlays

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

31 / 60

Gold with high percentage elongation is best for 😕

a. To remove metallic oxide

b. To improve the castability

c. To revert sagging during firing

d. Increase the bond strength

32 / 60

Main disadvantage of laminate technique of making impression is : ?

a. Cost factor is high

b. Difficult to manipulate

c. Maximum details are not produced

d. Bond between agar and alginate is not very strong

33 / 60

Alginate impression material deteriorates rapidly at 😕

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

b. Normal room temperature

c. Low temperature

d. Elevated temperature

34 / 60

Bis-GMA is a reaction product of 😕

a. Bis-phenol-A and glycidyl methacrylate

b. Bis-phenol-A and urethane dimethacrylate

c. Bis-phenol-A and methyl methacrylate

d. Urethane dimethacrylate and glycidyl

35 / 60

Stiffness of the material with passage of time is maximum in 😕

a. Addition silicones

b. Polysulfides

c. Condensation silicones

d. Polyether

36 / 60

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

a. Ag-Hg

b. Ag-Sn

c. Cu-Sn

d. Sn-Hg

37 / 60

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

a. Fifth generation bonding agent should be applied

b. Cured for longer period

c. Restoration should be build in increments

d. Not indicated

38 / 60

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

a. Silicates

b. Amalgam

c. Pure gold

d. Composites

39 / 60

Modifiers are added to plaster of Paris mainly to 😕

a. Reduce porosity

b. Regulate the setting time

c. Increase strength

d. Get a smooth surface

40 / 60

Ideal metal used for electroplating polysulfide impression is 😕

a. Cobalt

b. Copper

c. Silver

d. Nickel

41 / 60

Setting of plaster of Paris is a result of 😕

a. Indirect interaction between hemihydrates

b. Solubility difference between hemihydrates and dehydrate

c. Loss of water from hemihydrates

d. Interaction between hemihydrates and water

42 / 60

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

a. Hight ductility of metal

b. High malleafility of metal

c. Chemical bonding

d. Chemico-mechenical bonding

43 / 60

Chemically cured resin shrinks:?

a. Towards the center of bulk of material

b. On the surface only

c. On the base only

d. Away from the light source

44 / 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

45 / 60

The appropriate proportion of polymer to monomer component of dental resin by volume is generally 😕

a. 1:2

b. 2:1

c. 3:1

d. 1:3

46 / 60

Minimal thickness of base for adequate thermal insulation is 😕

a. 0.5 mm

b. 1 mm

c. 0.75 mm

d. 2 mm

47 / 60

KHN of enamel is 😕

a. 90-100

b. 600

c. 100

d. 300

48 / 60

Strength of dental porcelain is dependent on 😕

a. Composition

b. Rough

c. Resistance to fusion

d. No internal structure

49 / 60

The energy absorbed by a material when it is stressed to its proportional limit is 😕

a. Impact strength

b. Resilience

c. Toughness

d. Flexibility

50 / 60

The main ingredient of casting waxes is 😕

a. Carnauba wax

b. Gum dammar

c. Paraffin wax

d. Candellila wax

51 / 60

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

a. Brittleness

b. Toughness

c. Hardness

d. Springiness

52 / 60

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

a. Compomer

b. Composite

c. Glass ionomer

d. Hybrid ionomer

53 / 60

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

a. The amount of copper and tin

b. The amount of copper

c. The amount of copper and silver

d. The amount of copper and zinc

54 / 60

Impression plaster is a 😕

a. Thermoplastic material

b. Reversible impression material

c. Mucostatic material

d. Mucocompressive material

55 / 60

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

a. It takes more time for curing

b. It is more sensitive to oxygen inhibitors

c. It has not more working time available

d. It has more working time available

56 / 60

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

a. Kaolin

b. Silica

c. Potash

d. Feldspar

57 / 60

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

a. It does not have anticariogenic activity

b. It has an obtudant effect

c. It does not form reparative dentin

d. It has poor tensile strength

58 / 60

Most common use of Zinc oxide eugenol paste 😕

a. Wash impression for edentulous patients

b. Surgical paste

c. Dual impression for Partially edentulous patients

d. As interocclusal record material

59 / 60

Potato starch is contained in which impression material ?

a. Agar agar

b. Impression plaster

c. Potassium sulfate

d. Impression compound

60 / 60

Which of the following is used to alter contour of impression trays ?

a. Carding wax

b. Boxing wax

c. Beading wax

d. Utility wax

Your score is

The average score is 42%

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