Biomaterial Test

5 votes, 5 avg

164

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Biomaterial Test

1 / 60

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

a. Wall carpeting

b. Floor carpeting

c. Baseboard heating

d. Amalgam scrap stored in a closed container

2 / 60

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

a. Sn-Hg

b. Ag-Su

c. Cu-Sn

d. Ag-Hg

3 / 60

A glaze is placed over the finished composite restoration to 😕

a. No provide a better peripheral seal

b. To change the shade

c. Create a rough surface that is less receptive to extrinsic stain and plaque retention

d. To reduce surface porosities

4 / 60

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

a. Vapor temperature

b. Fusion temperature

c. Temperature of specificity

d. Heat temperature

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

d. Decreased polymerization of the resin

6 / 60

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

a. Hardness

b. Springiness

c. Toughness

d. Brittleness

7 / 60

Adhesion in composites is due to 😕

a. True chemical bonding to tooth structure

b. Presence of smear layer

c. Mechanical interlocking

d. Cohesion

8 / 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

9 / 60

Softening of impressing compound is best accomplished by 😕

a. Water bath

b. Oil bath

c. Dry heat

d. Open flame

10 / 60

Calcium hydroxide is used for 😕

a. Reinforce the restoration

b. Reduce maginal leakage

c. To prevent recurrent caries

d. Pulp capping

11 / 60

Which of the following statements about compomers are true ?

a. They typically are recommended for class II restorations.

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

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

d. They also are know as GIC

12 / 60

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

a. Sn-Hg

b. Ag-Hg

c. Cu-Sn

d. Ag-Sn

13 / 60

The desirable quality of porcelain is 😕

a. Requirement of color

b. Toughness without brittleness

c. Thermal expansion

d. Translucency

14 / 60

The main ingredient of casting waxes is 😕

a. Gum dammar

b. Paraffin wax

c. Candellila wax

d. Carnauba wax

15 / 60

Light source in the curing unit is usually 😕

a. Ultraviolet light bulb

b. Tungsten halogen light bulb

c. Infra red bulb

d. Sun light

16 / 60

When a mechanical device is used for mixing addition silicones 😕

a. More possibilities of contamination

b. There is no greater uniformity in proportioning and mixing

c. Mixing time is reduced

d. Mixing time is long

17 / 60

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

a. Resilience

b. Flexibility

c. Modulus of elasticity

d. Toughness

18 / 60

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

a. Carbone steal

b. They are attached to natural teeth with cements,

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

d. Artificial waxes teeth are attached

19 / 60

The most commonly used implant type presently is 😕

a. Transosteal implant

b. Intramucosal implant

c. Subperiosteal

d. Endosseous

20 / 60

Most common use of Zinc oxide eugenol paste 😕

a. Surgical paste

b. Dual impression for Partially edentulous patients

c. Wash impression for edentulous patients

d. As interocclusal record material

21 / 60

Dental personnel can do which one of the following to limit their exposure to mercury ?

a. Avoid touching freshly mixed amalgam

b. Sterilize amalgam scrap

c. Vacuum up a spill immediately

d. Avoid polishing amalgams

22 / 60

The maximum warpage of acrylic denture occurs during 😕

a. Polishing

b. Packing

c. Curing

d. Deflasking

23 / 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. All are correct

d. Microfilled

24 / 60

Property which distinguishes composites from filled acrylic resins 😕

a. Bonding between coupling agent and tooth structure

b. Adhesive bonding between matrix and filler

c. Bonding between coupling agent and filler

d. Bonding with tooth structure

25 / 60

One of the disadvantages of using quartz as filler in restorative resin is 😕

a. It has low affinity for resin matrix

b. It cannot be reduced to the size of microparticle composite

c. It cannot be polished

d. It cause abrasion and wearing of opposing tooth surface

26 / 60

Setting of plaster of Paris is a result of 😕

a. Solubility difference between hemihydrates and dehydrate

b. Indirect interaction between hemihydrates

c. Loss of water from hemihydrates

d. Interaction between hemihydrates and water

27 / 60

Metal has the following properties except 😕

a. Pure metals are not useful in dentistry

b. Electroplated silver and copper are used in dies

c. Metal is any element that ionizes positively in solution

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

28 / 60

Spot out incorrect statement regarding zinc in dentistry 😕

a. Pure zinc has no application in dentistry

b. It is low in strength

c. It is relatively soft and ductile

d. It does not oxidize

29 / 60

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

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

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

c. An undertriturated mass is crumbly and dull.

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

30 / 60

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

a. fluorite release

b. Floor carpeting

c. Amalgam scrap stored in a closed container

d. Baseboard heating

31 / 60

Ideal method firing of porcelain is by using 😕

a. Longer firing at high temperatures

b. Shorter firing at low temperatures

c. Longer firing at low temperatures

d. Shorter firing at higher temperatures

32 / 60

Proportional limit is defined as :

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

b. A deformation resulting from an applied load

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

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

33 / 60

Thermal conductivity is proportional to 😕

a. Type of metal

b. Fusion temperature

c. Hardness of metal

d. Area of conduction

34 / 60

The common characteristic for pit and fissure sealant composite resins, acrylic appliances and elastomeric impression materials is :

a. All of them can be employed as anterior filling materials

b. All of them are a result of secondary reaction

c. All of them are polymers

d. All of them should be heated before using

35 / 60

Clinical significance of smear layer :

a. Provides calcium for adhesion of composites

b. Increases the bonding action of the bonding agent

c. Improve the strength of the composite

d. Bonded to tooth structure and prevents composite adhesion

36 / 60

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

a. Hardness

b. Brittleness

c. Springiness

d. Toughness

37 / 60

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

a. Ag-Sn

b. Ag-Hg

c. Cu-Sn

d. Sn-Hg

38 / 60

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

a. Pheyl methacrylate

b. Poly (methyl methacrylate)

c. Polystyrene

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

39 / 60

Pick out the incorrect statement regarding alginate impressions 😕

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

b. Will be shrink as a result of syneresis

c. Will take up water and expand if kept wet

d. Is an irreversible hydrocolloid impression material

40 / 60

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

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

b. Marginal ditching along occlusal margins

c. Wear facets along the occlusal contach areas

d. Micrographs of alloys particles.

41 / 60

Which of the following represents the maximum safe concentration of mercury vapor in the breathing zone for a 40-hour workweek ?

a. 100 ng Hg/m3 of air

b. All are corrects

c. 30 ng Hg/m3 of air

d. 0.05 mg Hg/m3 of air

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

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

a. Silicate cement

b. Glass ionomer cement

c. Unfilled

d. Amalgam

44 / 60

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

a. Teratogenesis

b. Iatrogenesis

c. Biocompatibility

d. Carcinogenesis

45 / 60

Polyether is different from other elastomers in the following aspects 😕

a. High stiffiness

b. Can not be used as light cure material

c. Hydropholic in nature

d. Low stiffness

46 / 60

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

a. Space lattice

b. Stress

c. Strain

d. Amorphous material

47 / 60

Elgiloy arch wire is 😕

a. Cobalt-chromium-nickel alloy

b. Gold alloy

c. Optical fiber arch wire

d. β-titanium arch wire

48 / 60

For luting purpose, the film thickness should be 😕

a. 25 μm or less

b. up to 75 μm

c. minimum 50 μm

d. ideally 100 μm

49 / 60

In dental porcelains metallic oxides provide 😕

a. Color and increases the strength

b. Provides refractile property and increases strength

c. Color and provides refractile property

d. Color but decreases the strength

50 / 60

Condensation of porcelain is done by all the methods except 😕

a. Vibration method

b. Spatulation method

c. Ceramming method

d. Brush addition technique

51 / 60

The main resin constituent of polishable composite resin is 😕

a. Urethane dimethacrylate

b. Polycaronate

c. Cyanoacrylate

d. Polymethyl methacrylate

52 / 60

The most effective cement in stimulating tertiary dentin is 😕

a. Zinc silicophoshpate

b. Zinc phosphate

c. Polycardoxylate

d. Calcum hydroxide

53 / 60

The most accurate polysulfide impressions are made by using a custom acrylic tray because 😕

a. Custom tray made of plastic material ensures a uniform thickness of impression material

b. More pressure can be applied during impression making

c. It can hold more amount of impression material

d. The tray does not distort during impression making

54 / 60

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

a. Fusion temperature

b. Temperature of vaporization

c. Specific temperature

d. Latent heat

55 / 60

Ideal metal used for electroplating polysulfide impression is 😕

a. Cobalt

b. Silver

c. Copper

d. Nickel

56 / 60

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

a. Is the oldest luting agent

b. The least irritant to the pulp

c. Is used as a permanent restorative material in adults

d. Has an obtudant effect on the pulp

57 / 60

Silver has all the following characteristics except 😕

a. Addition of palladium to silver increases corrosion

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

c. Whitens when added to alloys

d. Silver points serve as a root canal filling material

58 / 60

Minimal thickness of base for adequate thermal insulation is 😕

a. 1 mm

b. 0.75 mm

c. 0.5 mm

d. 2 mm

59 / 60

For proper wetting, contact angle should be ideally 😕

a. 900

b. 450

c. 600

d. 00

60 / 60

Which of the following composites give rough surfaced finish ?

a. Microfilled composites

b. Conventional composites

c. Hybrid composites

d. Small particle filled composites

Your score is

The average score is 86%

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