Biomaterial Test

5 votes, 5 avg

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Biomaterial Test

1 / 60

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

a. Intramucosal frames

b. Transosteal frames

c. Endosseus implants

d. Subperiosteal

2 / 60

The following statements about dental porcelains are true except 😕

a. It is brittle in nature

b. Crystalline nature

c. Undergoes firing shrinkage

d. Undergoes discoloration

3 / 60

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

a. Modulus of elasticity

b. Flexibility

c. Toughness

d. Resilience

4 / 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 high speed

d. Diamond burs at low to medium speed

5 / 60

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

a. Gold alloy

b. Amalgam

c. Porcelain

d. Composite resin

6 / 60

Light source in the curing unit is usually 😕

a. Tungsten halogen light bulb

b. Infra red bulb

c. Ultraviolet light bulb

d. Sun light

7 / 60

Passiveness of chrome cobalt alloys is due to formation of 😕

a. Chromium carbide

b. Ferric oxide

c. Chromium oxide

d. Cobalt oxide

8 / 60

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

a. Saving the application of bonding agent

b. Providing strength to the restoration

c. Achieving complete polymerization

d. Compensating polymerization shrinkage

9 / 60

Higher mercury left in an amalgam leads to which of the following ?

a. Higher creep

b. High corrosion

c. Higher strength

d. Low corrosion

10 / 60

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

a. Triturating precapsulated alloy and mercury

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

c. Mixing in a mortar and pestle

d. A cover over the mixing arms on a triturator

11 / 60

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

a. Composite resin

b. Glass ionomer

c. Amalgam

d. Acrylic resin

12 / 60

Proportional limit is defined as :

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

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

c. A deformation resulting from an applied load

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

13 / 60

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

a. Glass ionomer cement

b. Amalgam

c. Silicate cement

d. Unfilled

14 / 60

The catalyst used for condensation silicones is 😕

a. Oleic acid

b. Lead dioxide

c. Platinum

d. Stannous octoate

15 / 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. Creep irregular high-copper

c. Tensile strength spherical high-copper

d. 1-hour compressive strength spherical high-copper

16 / 60

Hypersensitivity reactions like contact dermatitis is caused by 😕

a. Polysulfides

b. Polyether

c. Addition silicones

d. Condensation silicones

17 / 60

One of the following statements which one is incorrect regarding addition silicones 😕

a. Undetectable distortion on removal

b. Dimensionally stable even after 1 week

c. Can be used in automixing devices

d. No evolution of any byproduct under all circumstances

18 / 60

Which of the following statements is incorrect regarding hydroxyapatite as an implant material ?

a. It is a bio-inert material

b. It is used for augmenting alveolar ridges of filling bony defects

c. This material in granular form and is difficult

d. It is produced in block or granula form

19 / 60

Pick out the incorrect statement regarding alginate impressions 😕

a. Is an irreversible hydrocolloid impression material

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

c. Will be shrink as a result of syneresis

d. Will take up water and expand if kept wet

20 / 60

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

a. Adhesion

b. Flow

c. Biocompatibility

d. Dimensional stability

21 / 60

Elgiloy arch wire is 😕

a. Cobalt-chromium-nickel alloy

b. Gold alloy

c. β-titanium arch wire

d. Optical fiber arch wire

22 / 60

Montan waxes have the following properties except 😕

a. Have low melting points of 42oC

b. Are mineral waxes

c. Obtained by extraction from lignite

d. Hard, brittle and lustrous

23 / 60

Polyether is different from other elastomers in the following aspects 😕

a. Low stiffness

b. Hydropholic in nature

c. Can not be used as light cure material

d. High stiffiness

24 / 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

25 / 60

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

a. Ag-Su

b. Ag-Hg

c. Sn-Hg

d. Cu-Sn

26 / 60

Potato starch is contained in which impression material ?

a. Impression plaster

b. Agar agar

c. Impression compound

d. Potassium sulfate

27 / 60

A potentially toxic element in base metal alloys is 😕

a. Molybdenum

b. Beryllium

c. Boron

d. Magnesium

28 / 60

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

a. Quartz

b. Barium glass

c. Colloidal silica

d. Lithium aluminum silicate

29 / 60

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

a. 2:1

b. 3:1

c. 1:2

d. 1:3

30 / 60

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

a. No antibacterial action

b. High alkalinity

c. Low alkalinity

d. No Protein lysing effect

31 / 60

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

a. Metal

b. Gold alloy

c. Amalgam

d. Composite resin

32 / 60

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

a. It decreases the time for syneresis to occur

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

c. Faster rate of removal increases the yield strength

d. It is the easiest method of removal

33 / 60

Nickel in base metal alloys increase its 😕

a. Strength

b. Modulus of elasticity

c. Hardness and fusion temperature

d. S Ductility

34 / 60

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

a. Modulus of elasticity

b. Polymerization shrinkage

c. Thermal expansion

d. Water sorption

35 / 60

Crystalline materials have 😕

a. Well-defined melting

b. No well-defined melting

c. Less stable space lattice

d. No space lattice

36 / 60

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

a. Gold

b. Glass ionomer

c. Waxe

d. Ceramic

37 / 60

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

a. Peroxide-amine

b. Organic acid-peroxide

c. Organic acid-metal ion

d. Diketone-amine

38 / 60

Which of these statements are correct in terms of preparing a correctly triturated mass of amalgam ?

a. An overmixed mass is removed readily from the capsule but is soupy in appearance.

b. An undertriturated mass is crumbly and dull.

c. A correctly triturated mass is a smooth homogeneous, and dull.

d. Dental amalgam is a mixture of silver alloys and mercury.

39 / 60

The byproduct in condensation silicones is 😕

a. Propyl alcohol

b. Ethyl alcohol

c. Butyl alcohol

d. Methyl alcohol

40 / 60

Following are the functions of impression compound except 😕

a. To record mucostatic impressions

b. To make individual die impression with copper band

c. To make impression of edentulous ridge

d. To make special tray for final impression

41 / 60

The physical properties most desirable in set amalgam are which of the following ?

a. Low strength, low creep, low corrosion

b. Higher strength, low creep, low corrosion

c. Higher strength, high creep, high corrosion

d. Higher strength, high creep, low corrosion

42 / 60

The strain at which the plastic strain develops may be represented by 😕

a. Toughness, rigidity, resilience

b. Elastic limit, modulus of elasticity, tensile strength

c. Yield strength, tensile strength, toughness

d. Elastic limit, yield strength, proportional limit

43 / 60

The main advantage of composites compared to silicates cement is 😕

a. Coefficient of thermal expansion close to tooth structure

b. Color matching with the tooth structure is excellent

c. Practically insoluble in oral fluids

d. High modulus of resilience

44 / 60

Which of the following composites give rough surfaced finish ?

a. Hybrid composites

b. Small particle filled composites

c. Conventional composites

d. Microfilled composites

45 / 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 crack on cooling

c. Porcelain will wear off

d. Porcelain will provide good shade

46 / 60

Which of the following is called periphery wax ?

a. Sticky wax

b. Bite registration wax

c. Beading wax

d. Utility wax

47 / 60

Glass ionomer cenment is not recommended for 😕

a. Class III restoration

b. Class I restoration

c. Class V restoration

d. Class IV resoration

48 / 60

Which of the following materials are used for dental implants ?

a. Cobalt and chromium alloys

b. Metal alloys

c. Titanium

d. Gold alloys

49 / 60

The light from the visible light curing unit can cause 😕

a. Iritis

b. Retinal damage

c. Cataract

d. Corneal ulceration

50 / 60

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

a. Gypsum

b. Quartz

c. Silica

d. Water

51 / 60

In UV curing system the activator employed is 😕

a. Dibutyl phthalate

b. Methyl methacrylate

c. Benzoin methyl ether

d. Hydroquinone

52 / 60

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

a. Baseboard heating

b. Floor carpeting

c. Amalgam scrap stored in a closed container

d. Wall carpeting

53 / 60

In visible light-cured composites photo initiator molecule is 😕

a. Camphoroquinone

b. Benzoyl methyl ether

c. Toluidine

d. Bis-phenol-A

54 / 60

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

a. Spermitic and bees wax

b. Paraffin and microcrystalline wax

c. Montan and Japan coco

d. Carnauba and candellia

55 / 60

Metal has the following properties except 😕

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

b. Pure metals are not useful in dentistry

c. Electroplated silver and copper are used in dies

d. Metal is any element that ionizes positively in solution

56 / 60

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

a. Sagging of restoration

b. Secondary caries

c. Pulp inflammation

d. Porosity in restoration

57 / 60

Softening of impressing compound is best accomplished by 😕

a. Open flame

b. Oil bath

c. Dry heat

d. Water bath

58 / 60

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

a. Requires higher forces of condensation

b. Have longer setting time

c. Requires more mercury for trituration

d. Requires less amalgamation time

59 / 60

Gold with high percentage elongation is best for 😕

a. To revert sagging during firing

b. To improve the castability

c. To remove metallic oxide

d. Increase the bond strength

60 / 60

Dental porcelains are manufactured by a process termed as 😕

a. Fusing

b. Vulcanizing

c. Fritting

d. Sintering

Your score is

The average score is 42%

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