Biomaterial Test

5 votes, 5 avg

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Biomaterial Test

1 / 60

Following are the functions of impression compound except 😕

a. To make special tray for final impression

b. To make impression of edentulous ridge

c. To record mucostatic impressions

d. To make individual die impression with copper band

2 / 60

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

a. Glass ionomer cement

b. Unfilled

c. Silicate cement

d. Amalgam

3 / 60

Inorganic phase in a composite matrix 😕

a. Increases coefficient of thermal expansion

b. Increases the polymerization shrinkage

c. Increases the mechanical strength

d. Decreases the mechanical strength

4 / 60

The maximum warpage of acrylic denture occurs during 😕

a. Polishing

b. Curing

c. Deflasking

d. Packing

5 / 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 also are know as GIC

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

6 / 60

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

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

b. It is a bio-inert material

c. It is produced in block or granula form

d. This material in granular form and is difficult

7 / 60

Noble metal alloys are classified according to their 😕

a. Malleability

b. Melting temperature

c. Castability

d. Dental function

8 / 60

The noble or base metal alloys used for PFM should have the following requisite :

a. Should bond with dental porcelain

b. Should be brittle

c. Coefficient of thermal expansion should not be compatible with porcelain

d. Its melting temperature should be low in comparison with firing temperature of porcelain

9 / 60

The main function of zinc in amalgam is 😕

a. To increase the shelf-life of an amalgam

b. To prevent the creep

c. To produce delayed expansion

d. To increase the longevity of amalgam after setting

10 / 60

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

a. Glass ionomer

b. Hybrid ionomer

c. Composite

d. Compomer

11 / 60

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

a. Ag-Hg

b. Cu-Sn

c. Ag-Sn

d. Sn-Hg

12 / 60

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

a. Floor carpeting

b. fluorite release

c. Baseboard heating

d. Amalgam scrap stored in a closed container

13 / 60

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

a. Amalgam

b. Silicate

c. Direct resin-filling material

d. Zinc phosphate

14 / 60

Pick out the incorrect statement regarding alginate impressions 😕

a. Will take up water and expand if kept wet

b. Will be shrink as a result of syneresis

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

d. Is an irreversible hydrocolloid impression material

15 / 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

16 / 60

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

a. Metal

b. Amalgam

c. Gold alloy

d. Composite resin

17 / 60

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

a. No evolution of any byproduct under all circumstances

b. Can be used in automixing devices

c. Undetectable distortion on removal

d. Dimensionally stable even after 1 week

18 / 60

Gold casting alloys are classified as type I, II, III or IV among these, having highest hardness is 😕

a. Type II

b. Type I

c. Type III

d. Type IV

19 / 60

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

a. Brinell hardness test

b. Knoop hardness test

c. Vichers hardness test

d. Rockwell hardness test

20 / 60

The greatest amount of dimensional change after setting is exhibited by 😕

a. Addition silicones

b. Polysulfides

c. Polyethers

d. Condensation silicones

21 / 60

The restorative material used to restore a small portion of an anterior tooth should have which of the following properties ?

a. Esthetics

b. High strength

c. Amalgam

d. Ease of casting

22 / 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

23 / 60

Gypsum investments should not be heated above 😕

a. 17000C

b. 4500C

c. 7000C

d. 10000C

24 / 60

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

a. Cu-Sn

b. Ag-Su

c. Ag-Hg

d. Sn-Hg

25 / 60

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

a. Type III

b. Type II

c. Type I

d. Type IV

26 / 60

Amalgam is less prone to corrosion 😕

a. If it contains 4-6% of copper

b. If it contains zinc

c. If it contains 25-27% of tin

d. If devoid of the gamma 2 phase

27 / 60

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

a. Carding wax

b. Utility wax

c. Boxing wax

d. Beading wax

28 / 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. Polystyrene

d. Pheyl methacrylate

29 / 60

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

a. Gamma I Phase

b. Oxide

c. Sulphide

d. Gamma II Phase

30 / 60

The most commonly used implant type presently is 😕

a. Intramucosal implant

b. Transosteal implant

c. Endosseous

d. Subperiosteal

31 / 60

Thermal conductivity is proportional to 😕

a. Area of conduction

b. Type of metal

c. Hardness of metal

d. Fusion temperature

32 / 60

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

a. Avoid touching freshly mixed amalgam

b. Avoid polishing amalgams

c. Sterilize amalgam scrap

d. Vacuum up a spill immediately

33 / 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. 0.04 mg Hg/m3 of air

b. 30 mg Hg/m3 of air

c. 0.05 mg Hg/m3 of air

d. 100 mg Hg/m3 of air

34 / 60

Carnauba wax is preferred to candelilla wax as 😕

a. It provides luster to the pattern

b. It has low melting temperature

c. It is harder and has less flow

d. It is sticky

35 / 60

In dental plaster the main ingredient is 😕

a. Calcium phosphate

b. Calcium sulfate hemihydarate

c. Calcium anhydrate

d. Calcium sulfate dehydrate

36 / 60

Ideal method firing of porcelain is by using 😕

a. Shorter firing at higher temperatures

b. Longer firing at low temperatures

c. Shorter firing at low temperatures

d. Longer firing at high temperatures

37 / 60

Acrylic resins are used in which of the following ?

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

b. Anterior onlays

c. Denture bases

d. Posterior inlays

38 / 60

Sulfur contamination from natural latex gloves inhibits the setting of 😕

a. Alginate

b. Polyvinyl siloxane

c. Zinc oxide eugenol impression paste

d. Polyether

39 / 60

The impression material which is routinely used in auto mixing devicee system is 😕

a. Polyether

b. Condensation silicone

c. Polyvinyl siloxane

d. Polysulfied

40 / 60

Nickel sensitivity in the general population is 😕

a. 1% in the overall population

b. 3% for women

c. 3% for men

d. 11% for women

41 / 60

Which of the following statements about curing of composites are true ?

a. Exposure times of 2 to 3 seconds are needed for polymerization with visible light.

b. Lights with both blue and red wavelengths are equally effective for polymerization.

c. Before light activation, the base and catalyst pastes are mixed.

d. Light from an argon laser will activate polymerization.

42 / 60

Impression compound is characterized by 😕

a. Amorphous in nature with low thermal conductivity

b. Crystalline in nature with definite melting point

c. Crystalline in nature with high thermal conductivity

d. Amorphous in nature with high thermal conductivity

43 / 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

44 / 60

Elgiloy arch wire is 😕

a. Cobalt-chromium-nickel alloy

b. Gold alloy

c. Optical fiber arch wire

d. β-titanium arch wire

45 / 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

46 / 60

Nickel in base metal alloys increase its 😕

a. Strength

b. S Ductility

c. Hardness and fusion temperature

d. Modulus of elasticity

47 / 60

The main use of zinc oxide eugenol cement is 😕

a. Indirect pulp capping agent

b. Permanent restoration

c. Base

d. Temporary restoration

48 / 60

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

a. More pressure can be applied during impression making

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

c. It can hold more amount of impression material

d. The tray does not distort during impression making

49 / 60

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

a. All of them are a result of secondary reaction

b. All of them should be heated before using

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

d. All of them are polymers

50 / 60

Dispensing composite resins using a syringe is advantageous because it 😕

a. Increases strength and abrasive resistance

b. Increases surface smoothness

c. Decreases air voids in the restoration

d. Conserves the material

51 / 60

Adhesion in composites is due to 😕

a. True chemical bonding to tooth structure

b. Mechanical interlocking

c. Cohesion

d. Presence of smear layer

52 / 60

Glass ionomer cenment is not recommended for 😕

a. Class I restoration

b. Class III restoration

c. Class IV resoration

d. Class V restoration

53 / 60

Minimum light exposure time for composite resins should be 😕

a. 40 sec

b. 5 sec

c. 10 sec

d. 20 sec

54 / 60

Crystal structures of metals are all the following except 😕

a. Tetragonal

b. Cubic

c. Circular

d. Monoclinic

55 / 60

Oil of clove is sometimes used in preference to eugenal in ZOE paste because :

a. To increase setting time

b. Has a better reaction with zinc oxide

c. Reduces burning sensation of paste

d. It increases mixing property of paste and therefore improves impression recorded

56 / 60

Most commonly used pit and fissure sealant is 😕

a. Polyurethane

b. Filled acrylic

c. Bis-GMA resin

d. Unfilled acrylic

57 / 60

A full crown on a maxillary anterior tooth may be restored with which of the following restorative materials ?

a. Composite resin

b. Ceramic

c. Gold alloys

d. Amalgam

58 / 60

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

a. Polyether

b. Polysulfides

c. Addition silicones

d. Condensation silicones

59 / 60

The catalyst used for condensation silicones is 😕

a. Stannous octoate

b. Lead dioxide

c. Platinum

d. Oleic acid

60 / 60

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

a. Artificial waxes teeth are attached

b. Carbone steal

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

d. They are attached to natural teeth with cements,

Your score is

The average score is 71%

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