Biomaterial Test

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Biomaterial Test

1 / 60

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

a. Diamond burs at low to medium speed

b. Carbide burs at high speed

c. Carbide burs at low to medium speed

d. Diamond burs at high speed

2 / 60

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

a. Triturating precapsulated alloy and mercury

b. A cover over the mixing arms on a triturator

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

d. Mixing in a mortar and pestle

3 / 60

Inorganic phase in a composite matrix 😕

a. Increases the mechanical strength

b. Decreases the mechanical strength

c. Increases the polymerization shrinkage

d. Increases coefficient of thermal expansion

4 / 60

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

a. Polysulfides

b. Polyether

c. Condensation silicones

d. Addition silicones

5 / 60

Calcium hydroxide is used for 😕

a. Reduce maginal leakage

b. Reinforce the restoration

c. Pulp capping

d. To prevent recurrent caries

6 / 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 zinc

d. The amount of copper and silver

7 / 60

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

a. Polymerization shrinkage

b. Water sorption

c. Thermal expansion

d. Modulus of elasticity

8 / 60

The reason for hydroxyapatite coating on implant biomaterials is 😕

a. Greater bony opposition

b. Prolonged healing time

c. Lesser bony apposition

d. Presence of fibrous tissue

9 / 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. 0.04 mg Hg/m3 of air

d. 0.05 mg Hg/m3 of air

10 / 60

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

a. Accelerators

b. Fillers

c. Retarders

d. Reactors

11 / 60

KHN of enamel is 😕

a. 90-100

b. 300

c. 100

d. 600

12 / 60

The most commonly used implant type presently is 😕

a. Subperiosteal

b. Transosteal implant

c. Intramucosal implant

d. Endosseous

13 / 60

The product that is formed on the surface of the amalgam restoration and frequently result in discoloration is 😕

a. Sulphide

b. Gamma I Phase

c. Oxide

d. Gamma II Phase

14 / 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

15 / 60

Commonly used coloring agent in impression plaster is 😕

a. Metallic oxide

b. Indigo dye

c. Alizarin red

d. Congo red

16 / 60

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

a. Toughness

b. Brittleness

c. Springiness

d. Hardness

17 / 60

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

a. Elastic limit, yield strength, proportional limit

b. Yield strength, tensile strength, toughness

c. Toughness, rigidity, resilience

d. Elastic limit, modulus of elasticity, tensile strength

18 / 60

In an alloy oxygen scavenger is 😕

a. Copper

b. Palladium

c. Silver

d. Zinc

19 / 60

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

a. Glass ionomer cement

b. Silicate cement

c. Composite resin

d. Unfilled acrylic resin

20 / 60

The chemistry behind the condensation of the amalgam is to 😕

a. Condense the unattacked gamma I particles

b. To reduce gamma II particules

c. Condense the unattacked gamma II particles

d. Condense the unattacked gamma particles

21 / 60

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

a. Addition silicone

b. Polysulfide

c. Polyether

d. Condensation silicone

22 / 60

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

a. Chemico-mechenical bonding

b. Chemical bonding

c. Hight ductility of metal

d. High malleafility of metal

23 / 60

Most commonly used pit and fissure sealant is 😕

a. Polyurethane

b. Unfilled acrylic

c. Filled acrylic

d. Bis-GMA resin

24 / 60

A potentially toxic element in base metal alloys is 😕

a. Molybdenum

b. Beryllium

c. Boron

d. Magnesium

25 / 60

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

a. Triturating precapsulated alloy and mercury

b. A cover over the mixing arms on a triturator

c. Mixing in a mortar and pestle

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

26 / 60

Hypersensitivity reactions like contact dermatitis is caused by 😕

a. Condensation silicones

b. Addition silicones

c. Polysulfides

d. Polyether

27 / 60

Which of the following materials are used for dental implants ?

a. Gold alloys

b. Cobalt and chromium alloys

c. Titanium

d. Metal alloys

28 / 60

Hand instruments for composites are made of 😕

a. Stainless steel

b. Teflon-coated metal

c. Titanium

d. Carbon steel

29 / 60

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

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

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

c. Microfilled

d. All are correct

30 / 60

Spot out incorrect statement regarding zinc in dentistry 😕

a. It is relatively soft and ductile

b. Pure zinc has no application in dentistry

c. It is low in strength

d. It does not oxidize

31 / 60

Strength of dental porcelain is dependent on 😕

a. Rough

b. No internal structure

c. Composition

d. Resistance to fusion

32 / 60

Which of the following composites give rough surfaced finish ?

a. Small particle filled composites

b. Hybrid composites

c. Conventional composites

d. Microfilled composites

33 / 60

Main disadvantage of denture base soft reliner is 😕

a. It can not lead to fungal growth

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

c. It can not lead to cleaned property

d. It can be cleaned properly

34 / 60

Which one of the following is not a criterion for a failed high-copper dental amalgam restorations ?

a. Marginal ditching along occlusal margins

b. Wear facets along the occlusal contach areas

c. Micrographs of alloys particles.

d. Creep of the restoration out of the cavity preparation in proximal areas

35 / 60

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

a. Amalgam

b. Composite resin

c. Metal

d. Gold alloy

36 / 60

Nickel in base metal alloys increase its 😕

a. Modulus of elasticity

b. Strength

c. S Ductility

d. Hardness and fusion temperature

37 / 60

Dental porcelains are manufactured by a process termed as 😕

a. Vulcanizing

b. Fusing

c. Fritting

d. Sintering

38 / 60

Greening effect of porcelain is due to 😕

a. Platinum

b. Golde

c. Silver

d. Palladium

39 / 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

40 / 60

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

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

b. Poly (methyl methacrylate)

c. Pheyl methacrylate

d. Polystyrene

41 / 60

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

a. This material in granular form and is difficult

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

c. It is produced in block or granula form

d. It is a bio-inert material

42 / 60

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

a. Springiness

b. Hardness

c. Toughness

d. Brittleness

43 / 60

Stearic acid in impression compound 😕

a. Reduces flow

b. Reduces plasticity

c. Increase setting time

d. Reduces brittleness

44 / 60

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

a. Temperature of vaporization

b. Fusion temperature

c. Specific temperature

d. Latent heat

45 / 60

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

a. Amalgam

b. Ceramic

c. Silver alloys

d. Gold alloy

46 / 60

The gelation temperature of agar hydrocolloid impression material should be 😕

a. 37-450C

b. 100C higher than mouth temperature

c. 45-600C

d. Far below the oral temperature

47 / 60

Which of the following statements about compomers are true ?

a. They typically are recommended for class II restorations.

b. They also are know as GIC

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

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

48 / 60

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

a. Artificial acrylic teeth are attached

b. They are attached to lower natural teeth with cements,

c. They are attached to natural teeth with cements,

d. They are attached to upper natural teeth with cements,

49 / 60

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

a. Providing strength to the restoration

b. Compensating polymerization shrinkage

c. Achieving complete polymerization

d. Saving the application of bonding agent

50 / 60

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

a. Vichers hardness test

b. Rockwell hardness test

c. Brinell hardness test

d. Knoop hardness test

51 / 60

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

a. Cu-Sn

b. Sn-Hg

c. Ag-Sn

d. Ag-Hg

52 / 60

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

a. Subsequent oxidation of the tertiary amine

b. Increased solubility of the resin

c. Decreased polymerization of the resin

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

53 / 60

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

a. increase strength

b. Reduce brittleness

c. Reduce porosity

d. Reduce firing shrinkage

54 / 60

Passiveness of chrome cobalt alloys is due to formation of 😕

a. Cobalt oxide

b. Ferric oxide

c. Chromium oxide

d. Chromium carbide

55 / 60

Full denture bases are usually made from which of the following materials ?

a. Acrylic resin

b. Ceramic

c. Composite restorative resins

d. Gold alloys

56 / 60

The most effective cement in stimulating tertiary dentin is 😕

a. Calcum hydroxide

b. Zinc silicophoshpate

c. Zinc phosphate

d. Polycardoxylate

57 / 60

Porcelain denture teeth 😕

a. Have higher coefficient of thermal expansion than resin teeth

b. Are more resistant of abrasion than gold

c. Are easy to grind and polish

d. Have decreased abrasion resistance than dentin

58 / 60

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

a. Floor carpeting

b. Amalgam scrap stored in a closed container

c. fluorite release

d. Baseboard heating

59 / 60

Impression compound is characterized by 😕

a. Crystalline in nature with high thermal conductivity

b. Crystalline in nature with definite melting point

c. Amorphous in nature with high thermal conductivity

d. Amorphous in nature with low thermal conductivity

60 / 60

Setting of plaster of Paris is a result of 😕

a. Indirect interaction between hemihydrates

b. Interaction between hemihydrates and water

c. Solubility difference between hemihydrates and dehydrate

d. Loss of water from hemihydrates

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