Biomaterial Test

5 votes, 5 avg

164

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Biomaterial Test

1 / 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. Gamma II Phase

d. Oxide

2 / 60

Which has the highest viscoelastic property and requires more time to recover from deformation ?

a. Condensation silicone

b. Addition silicone

c. Polysulfide

d. Polyether

3 / 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

4 / 60

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

a. Silver alloys

b. Amalgam

c. Gold alloy

d. Ceramic

5 / 60

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

a. Composite

b. Hybrid ionomer

c. Compomer

d. Glass ionomer

6 / 60

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

a. No Protein lysing effect

b. High alkalinity

c. Low alkalinity

d. No antibacterial action

7 / 60

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

a. Addition silicone

b. Polyether

c. Condensation silicone

d. Polysulfide

8 / 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. Micrographs of alloys particles.

c. Marginal ditching along occlusal margins

d. Wear facets along the occlusal contach areas

9 / 60

Which of the following occurs when dental amalgam is overmixed ?

a. Corrosion decreases

b. Tensile strength increases

c. Compressive strength decreases

d. Corrosion increases

10 / 60

Montan waxes have the following properties except 😕

a. Obtained by extraction from lignite

b. Are mineral waxes

c. Have low melting points of 42oC

d. Hard, brittle and lustrous

11 / 60

The function of gum dammar in inlay wax is 😕

a. Less strength to wax

b. To improve smoothness of pattern

c. No smoothness of pattern

d. No resistance to carving

12 / 60

Proconditioning before GIC restoration is done in order to 😕

a. Create tags

b. Remove smear layer

c. Provide more strenght

d. Facilitate mechanical bonding

13 / 60

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

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

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

c. Artificial acrylic teeth are attached

d. They are attached to natural teeth with cements,

14 / 60

Crystal structures of metals are all the following except 😕

a. Circular

b. Tetragonal

c. Monoclinic

d. Cubic

15 / 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

16 / 60

Which of the following is called periphery wax ?

a. Sticky wax

b. Beading wax

c. Bite registration wax

d. Utility wax

17 / 60

The most effective cement in stimulating tertiary dentin is 😕

a. Polycardoxylate

b. Calcum hydroxide

c. Zinc silicophoshpate

d. Zinc phosphate

18 / 60

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

a. Sn-Hg

b. Ag-Hg

c. Cu-Sn

d. Ag-Su

19 / 60

The main use of zinc oxide eugenol cement is 😕

a. Permanent restoration

b. Base

c. Indirect pulp capping agent

d. Temporary restoration

20 / 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

21 / 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 does not oxidize

d. It is relatively soft and ductile

22 / 60

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

a. The tray does not distort during impression making

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

c. More pressure can be applied during impression making

d. It can hold more amount of impression material

23 / 60

Polyether is different from other elastomers in the following aspects 😕

a. Can not be used as light cure material

b. Low stiffness

c. High stiffiness

d. Hydropholic in nature

24 / 60

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

a. Dimensionally stable even after 1 week

b. Undetectable distortion on removal

c. Can be used in automixing devices

d. No evolution of any byproduct under all circumstances

25 / 60

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

a. Ag-Hg

b. Sn-Hg

c. Ag-Su

d. Cu-Sn

26 / 60

In a porcelain fused to metal restoration, when the coefficient of thermal expansion of metal and porcelain are different 😕

a. Porcelain will crack on cooling

b. Porcelain will wear off

c. Porcelain will not bond with metal

d. Porcelain will provide good shade

27 / 60

The main ingredient of casting waxes is 😕

a. Candellila wax

b. Carnauba wax

c. Gum dammar

d. Paraffin wax

28 / 60

Porcelain-bonded to metal is stronger when fired 😕

a. Several times in air

b. Under compression

c. Under low temperature

d. After metal is tempered

29 / 60

Commonly used viscosity controller in composites is 😕

a. Polyurethanes

b. Bis-GAM

c. Methyl methacrylate

d. TEG-DMA

30 / 60

The most commonly used implant type presently is 😕

a. Endosseous

b. Subperiosteal

c. Intramucosal implant

d. Transosteal implant

31 / 60

Pick out the incorrect statement regarding alginate impressions 😕

a. Will take up water and expand if kept wet

b. Is an irreversible hydrocolloid impression material

c. Will be shrink as a result of syneresis

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

32 / 60

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

a. Hight ductility of metal

b. Chemico-mechenical bonding

c. High malleafility of metal

d. Chemical bonding

33 / 60

Zinc oxide eugenal impression should be removed from oral cavity :

a. When it can be easily indented by a blunt instrument

b. When the material is glossy

c. When the material cannot be intended by a blunt instrument

d. Exactly after four minutes after kneading

34 / 60

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

a. 2:1

b. 1:2

c. 1:3

d. 3:1

35 / 60

Gold with high percentage elongation is best for 😕

a. Increase the bond strength

b. To improve the castability

c. To revert sagging during firing

d. To remove metallic oxide

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

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

d. An undertriturated mass is crumbly and dull.

37 / 60

Porcelain denture teeth 😕

a. Are easy to grind and polish

b. Are more resistant of abrasion than gold

c. Have higher coefficient of thermal expansion than resin teeth

d. Have decreased abrasion resistance than dentin

38 / 60

In dental porcelains metallic oxides provide 😕

a. Color and provides refractile property

b. Provides refractile property and increases strength

c. Color but decreases the strength

d. Color and increases the strength

39 / 60

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

a. They are attached to natural teeth with cements,

b. Artificial waxes teeth are attached

c. Carbone steal

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

40 / 60

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

a. Ag-Sn

b. Ag-Hg

c. Sn-Hg

d. Cu-Sn

41 / 60

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

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

b. To increase setting time

c. Reduces burning sensation of paste

d. Has a better reaction with zinc oxide

42 / 60

Setting time of alginate can be better controlled by 😕

a. Chemical accelerators and retarders

b. Changing water: powder ratio

c. Temperature of water used of mixing

d. Mixing time

43 / 60

Calcium hydroxide is used for 😕

a. Pulp capping

b. To prevent recurrent caries

c. Reinforce the restoration

d. Reduce maginal leakage

44 / 60

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

a. Amalgam scrap stored in a closed container

b. Floor carpeting

c. Wall carpeting

d. Baseboard heating

45 / 60

Silver has all the following characteristics except 😕

a. Addition of palladium to silver increases corrosion

b. Silver points serve as a root canal filling material

c. Whitens when added to alloys

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

46 / 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 restores the strength of the clinical crown to its original condition.

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

d. The most effective bonding agents contain copalite.

47 / 60

Condensation of porcelain is done by all the methods except 😕

a. Spatulation method

b. Ceramming method

c. Vibration method

d. Brush addition technique

48 / 60

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

a. Beading wax

b. Boxing wax

c. Carding wax

d. Utility wax

49 / 60

The following statements about dental porcelains are true except 😕

a. It is brittle in nature

b. Undergoes discoloration

c. Undergoes firing shrinkage

d. Crystalline nature

50 / 60

Thermal conductivity is proportional to 😕

a. Type of metal

b. Hardness of metal

c. Area of conduction

d. Fusion temperature

51 / 60

All are properties of waxes except 😕

a. Flow

b. Creep

c. Plastic deformation

d. Solidification shrinkage

52 / 60

Potato starch is contained in which impression material ?

a. Impression plaster

b. Impression compound

c. Potassium sulfate

d. Agar agar

53 / 60

Most commonly used pit and fissure sealant is 😕

a. Unfilled acrylic

b. Bis-GMA resin

c. Polyurethane

d. Filled acrylic

54 / 60

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

a. Polyethers

b. Addition silicones

c. Condensation silicones

d. Polysulfides

55 / 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

56 / 60

KHN of enamel is 😕

a. 90-100

b. 600

c. 300

d. 100

57 / 60

Main disadvantage of laminate technique of making impression is : ?

a. Bond between agar and alginate is not very strong

b. Difficult to manipulate

c. Maximum details are not produced

d. Cost factor is high

58 / 60

Silver in the set amalgam alloy tends to have the following effect 😕

a. Hydrolyzes the water if contaminated

b. Decreases the setting time

c. Produces contraction

d. Decreases ductility

59 / 60

Hypersensitivity reactions like contact dermatitis is caused by 😕

a. Polyether

b. Condensation silicones

c. Polysulfides

d. Addition silicones

60 / 60

A cavity varnish used for lining the preparation for a dental amalgam restoration will :

a. Provide electrical insulation

b. Provide thermal insulation

c. Reduce early marginal leakage tooth structure

d. Provide strength of amalgam

Your score is

The average score is 86%

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