Biomaterial Test

5 votes, 5 avg

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Biomaterial Test

1 / 60

The chemistry behind the condensation of the amalgam is to 😕

a. Condense the unattacked gamma particles

b. To reduce gamma II particules

c. Condense the unattacked gamma II particles

d. Condense the unattacked gamma I particles

2 / 60

Which statements are true for bonding of amalgam to tooth structure ?

a. Shear bond strength using amalgam bonding to teeth in clinically proven to be as high as that for bonding composites to teeth.

b. The use of amalgam bonding reduces marginal leakage of amalgam restorations.

c. The use of amalgam bonding restores the strength of the clinical crown to its original condition.

d. The most effective bonding agents contain copalite.

3 / 60

Minimal thickness of base for adequate thermal insulation is 😕

a. 0.75 mm

b. 2 mm

c. 0.5 mm

d. 1 mm

4 / 60

Hypersensitivity reactions like contact dermatitis is caused by 😕

a. Polyether

b. Addition silicones

c. Condensation silicones

d. Polysulfides

5 / 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

6 / 60

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

a. Carbide burs at low to medium speed

b. Diamond burs at high speed

c. Diamond burs at low to medium speed

d. Carbide burs at high speed

7 / 60

Minimum light exposure time for composite resins should be 😕

a. 40 sec

b. 10 sec

c. 20 sec

d. 5 sec

8 / 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 impression of edentulous ridge

d. To make special tray for final impression

9 / 60

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

a. Ag-Hg

b. Cu-Sn

c. Sn-Hg

d. Ag-Su

10 / 60

Elgiloy arch wire is 😕

a. Gold alloy

b. β-titanium arch wire

c. Cobalt-chromium-nickel alloy

d. Optical fiber arch wire

11 / 60

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

a. They cannot be soldered or welded

b. They can be heat treated

c. Their hardness is comparable to stainless steel

d. They have excellent tarnish and corrosion resistance

12 / 60

Most common use of Zinc oxide eugenol paste 😕

a. Surgical paste

b. As interocclusal record material

c. Dual impression for Partially edentulous patients

d. Wash impression for edentulous patients

13 / 60

A direct restorative material used frequently to restore a portion of a posterior tooth that is subject to large biting forces would possess which of the following properties ?

a. High strength

b. Ease of casting

c. Thermal insulation

d. Esthetics

14 / 60

The maximum warpage of acrylic denture occurs during 😕

a. Packing

b. Curing

c. Deflasking

d. Polishing

15 / 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 upper natural teeth with cements,

c. They are attached to natural teeth with cements,

d. Artificial acrylic teeth are attached

16 / 60

The main function of zinc in amalgam is 😕

a. To prevent the creep

b. To increase the longevity of amalgam after setting

c. To increase the shelf-life of an amalgam

d. To produce delayed expansion

17 / 60

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

a. Toughness

b. Resilience

c. Impact strength

d. Flexibility

18 / 60

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

a. Unfilled

b. Amalgam

c. Silicate cement

d. Glass ionomer cement

19 / 60

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

a. The least irritant to the pulp

b. Is the oldest luting agent

c. Is used as a permanent restorative material in adults

d. Has an obtudant effect on the pulp

20 / 60

Commonly used coloring agent in impression plaster is 😕

a. Metallic oxide

b. Congo red

c. Alizarin red

d. Indigo dye

21 / 60

Most commonly used pit and fissure sealant is 😕

a. Polyurethane

b. Bis-GMA resin

c. Filled acrylic

d. Unfilled acrylic

22 / 60

In UV curing system the activator employed is 😕

a. Hydroquinone

b. Methyl methacrylate

c. Dibutyl phthalate

d. Benzoin methyl ether

23 / 60

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

a. Porcelain

b. Amalgam

c. Composite resin

d. Gold alloy

24 / 60

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

a. Is combined primarily with silver

b. Has the toxic properties of unreacted mercury

c. Composite restorative resins

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

25 / 60

Which of the following composites give rough surfaced finish ?

a. Conventional composites

b. Microfilled composites

c. Small particle filled composites

d. Hybrid composites

26 / 60

Hand instruments for composites are made of 😕

a. Carbon steel

b. Teflon-coated metal

c. Titanium

d. Stainless steel

27 / 60

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

a. Polysulfides

b. Polyether

c. Condensation silicones

d. Addition silicones

28 / 60

Which of the following statements about compomers are true ?

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

b. They also are know as GIC

c. They typically are recommended for class II restorations.

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

29 / 60

Montan waxes have the following properties except 😕

a. Are mineral waxes

b. Have low melting points of 42oC

c. Hard, brittle and lustrous

d. Obtained by extraction from lignite

30 / 60

The main ingredient of casting waxes is 😕

a. Paraffin wax

b. Gum dammar

c. Carnauba wax

d. Candellila wax

31 / 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

32 / 60

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

a. Type IV

b. Type I

c. Type II

d. Type III

33 / 60

Working time of denture resin should be at least 😕

a. 20 minutes

b. 5 minutes

c. 10 minutes

d. 15 minutes

34 / 60

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

a. Have longer setting time

b. Requires higher forces of condensation

c. Requires more mercury for trituration

d. Requires less amalgamation time

35 / 60

In an alloy oxygen scavenger is 😕

a. Copper

b. Silver

c. Zinc

d. Palladium

36 / 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

37 / 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 has low affinity for resin matrix

d. It cause abrasion and wearing of opposing tooth surface

38 / 60

Conventional dental amalgam alloy contains 😕

a. Silver, tin, copper and zinc

b. Silver, tin, palladium and zinc

c. Silver, mercury, copper and mercury

d. Silver, mercury, copper and zinc

39 / 60

The temperature at which a solid changes into liquid is called 😕

a. Latent heat

b. Specific temperature

c. Fusion temperature

d. Temperature of vaporization

40 / 60

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

a. They are removable and attached to teeth with clasps.

b. They are attached to natural teeth with cements,

c. Carbone steal

d. Artificial waxes teeth are attached

41 / 60

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

a. Springiness

b. Hardness

c. Toughness

d. Brittleness

42 / 60

Which of the following is called periphery wax ?

a. Sticky wax

b. Beading wax

c. Bite registration wax

d. Utility wax

43 / 60

Carnauba wax is preferred to candelilla wax as 😕

a. It provides luster to the pattern

b. It is sticky

c. It is harder and has less flow

d. It has low melting temperature

44 / 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

45 / 60

Gypsum investments should not be heated above 😕

a. 4500C

b. 7000C

c. 10000C

d. 17000C

46 / 60

Wrought metal 😕

a. Can be formed by working on a cast metal

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

c. Cannot be rendered corrosion resistant

d. Cannot be heat treated

47 / 60

Passiveness of chrome cobalt alloys is due to formation of 😕

a. Ferric oxide

b. Chromium carbide

c. Cobalt oxide

d. Chromium oxide

48 / 60

Porcelain-bonded to metal is stronger when fired 😕

a. Under compression

b. Several times in air

c. After metal is tempered

d. Under low temperature

49 / 60

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

a. No antibacterial action

b. No Protein lysing effect

c. Low alkalinity

d. High alkalinity

50 / 60

Silver has all the following characteristics except 😕

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

b. Silver points serve as a root canal filling material

c. Whitens when added to alloys

d. Addition of palladium to silver increases corrosion

51 / 60

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

a. 3:1

b. 2:1

c. 1:3

d. 1:2

52 / 60

In dental porcelains metallic oxides provide 😕

a. Color and provides refractile property

b. Color but decreases the strength

c. Provides refractile property and increases strength

d. Color and increases the strength

53 / 60

Pick out the incorrect statement regarding alginate impressions 😕

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

b. Is an irreversible hydrocolloid impression material

c. Will be shrink as a result of syneresis

d. Will take up water and expand if kept wet

54 / 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. 0.04 mg Hg/m3 of air

c. 0.05 mg Hg/m3 of air

d. 100 mg Hg/m3 of air

55 / 60

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

a. Floor carpeting

b. Amalgam scrap stored in a closed container

c. Wall carpeting

d. Baseboard heating

56 / 60

Glass ionomer cenment is not recommended for 😕

a. Class III restoration

b. Class I restoration

c. Class V restoration

d. Class IV resoration

57 / 60

The byproduct in condensation silicones is 😕

a. Methyl alcohol

b. Ethyl alcohol

c. Butyl alcohol

d. Propyl alcohol

58 / 60

KHN of enamel is 😕

a. 100

b. 300

c. 90-100

d. 600

59 / 60

Which of the following mixing methods permits the escape of dental amalgam mercury vapor ?

a. Proportioning mercury and alloy into a friction-fit capsule

b. Triturating precapsulated alloy and mercury

c. A cover over the mixing arms on a triturator

d. Mixing in a mortar and pestle

60 / 60

The reason for hydroxyapatite coating on implant biomaterials is 😕

a. Prolonged healing time

b. Greater bony opposition

c. Lesser bony apposition

d. Presence of fibrous tissue

Your score is

The average score is 73%

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