Biomaterial Test – testnisset.com

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Biomaterial Test

1 / 60

The most commonly used implant type presently is 😕

a. Intramucosal implant

b. Subperiosteal

c. Transosteal implant

d. Endosseous

2 / 60

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

a. Decreases ductility

b. Decreases the setting time

c. Hydrolyzes the water if contaminated

d. Produces contraction

3 / 60

Working time of denture resin should be at least 😕

a. 5 minutes

b. 10 minutes

c. 15 minutes

d. 20 minutes

4 / 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 does not oxidize

d. It is low in strength

5 / 60

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

a. Adhesion

b. Biocompatibility

c. Flow

d. Dimensional stability

6 / 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. 30 ng Hg/m3 of air

c. All are corrects

d. 0.05 mg Hg/m3 of air

7 / 60

Which of the following statements apply to the packable composites ?

a. Radiopaque

b. They are radiolucent.

c. Their wear rate is low (3.5 μm/year). Which is similar to that of amalgam.

d. Their depth of cure allows bulk polymerization, which has been shown to be clinically effective.

8 / 60

Bis-GMA is a reaction product of 😕

a. Bis-phenol-A and glycidyl methacrylate

b. Bis-phenol-A and urethane dimethacrylate

c. Urethane dimethacrylate and glycidyl

d. Bis-phenol-A and methyl methacrylate

9 / 60

Stearic acid in impression compound 😕

a. Reduces flow

b. Increase setting time

c. Reduces plasticity

d. Reduces brittleness

10 / 60

Once amalgamation has occurred, which of the following is true of mercury ?

a. Composite restorative resins

b. Can form at the surface of amalgam restorations if heated to 0° C

c. Has the toxic properties of unreacted mercury

d. Is combined primarily with silver

11 / 60

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

a. Specific temperature

b. Latent heat

c. Fusion temperature

d. Temperature of vaporization

12 / 60

Greater ratio fo zinc oxide to eugenol will have the following effect on setting time 😕

a. Depends on rate of mixing

b. Increases setting time

c. Does not alter setting time

d. Decreases setting time

13 / 60

Elgiloy arch wire is 😕

a. Optical fiber arch wire

b. β-titanium arch wire

c. Gold alloy

d. Cobalt-chromium-nickel alloy

14 / 60

The primary difference between low- and high-copper amalgams is which of the following ?

a. The amount of copper and zinc

b. The amount of copper and silver

c. The amount of copper and tin

d. The amount of copper

15 / 60

Nickel in base metal alloys increase its 😕

a. S Ductility

b. Modulus of elasticity

c. Strength

d. Hardness and fusion temperature

16 / 60

Which of the following waxes used to align of castings before soldering ?

a. Base plate wax

b. Carding wax

c. Sticky wax

d. Utility wax

17 / 60

A measure of ductility of a material is referred to as 😕

a. Yield strength

b. Flexibility

c. Proportional limit

d. Percentage elongation

18 / 60

Metal has the following properties except 😕

a. Electroplated silver and copper are used in dies

b. Metal is any element that ionizes positively in solution

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

d. Pure metals are not useful in dentistry

19 / 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

20 / 60

Calcium hydroxide is used for 😕

a. Reduce maginal leakage

b. To prevent recurrent caries

c. Pulp capping

d. Reinforce the restoration

21 / 60

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

a. Vapor temperature

b. Fusion temperature

c. Heat temperature

d. Temperature of specificity

22 / 60

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

a. Porosity in restoration

b. Secondary caries

c. Sagging of restoration

d. Pulp inflammation

23 / 60

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

a. It is produced in block or granula form

b. It is a bio-inert material

c. This material in granular form and is difficult

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

24 / 60

Amalgam is less prone to corrosion 😕

a. If devoid of the gamma 2 phase

b. If it contains 25-27% of tin

c. If it contains zinc

d. If it contains 4-6% of copper

25 / 60

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

a. Rockwell hardness test

b. Vichers hardness test

c. Brinell hardness test

d. Knoop hardness test

26 / 60

Which of the following statements about adhesion of composite restorations to tooth structure are true ?

a. Most bonding agent bond more effectively to a dry tooth surface.

b. The bonding agent forms a micromechanical bond with enamel but a chemical bond with dentin.

c. The bonding agent forms a hybrid layer with enamel.

d. Bonding is achieved to enamel by application of an acid etchant followed by application of a bonding agent and then the composites resin.

27 / 60

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

a. Toughness

b. Flexibility

c. Resilience

d. Modulus of elasticity

28 / 60

In the cavities which are more than 2mm deep a light-cured restoration is 😕

a. Not indicated

b. Fifth generation bonding agent should be applied

c. Cured for longer period

d. Restoration should be build in increments

29 / 60

Chemically cured resin shrinks:?

a. On the surface only

b. Towards the center of bulk of material

c. On the base only

d. Away from the light source

30 / 60

Setting of plaster of Paris is a result of 😕

a. Indirect interaction between hemihydrates

b. Loss of water from hemihydrates

c. Solubility difference between hemihydrates and dehydrate

d. Interaction between hemihydrates and water

31 / 60

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

a. Spermitic and bees wax

b. Montan and Japan coco

c. Carnauba and candellia

d. Paraffin and microcrystalline wax

32 / 60

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

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

b. Polystyrene

c. Poly (methyl methacrylate)

d. Pheyl methacrylate

33 / 60

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

a. Carding wax

b. Utility wax

c. Beading wax

d. Boxing wax

34 / 60

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

a. Ag-Sn

b. Sn-Hg

c. Ag-Hg

d. Cu-Sn

35 / 60

Minimum light exposure time for composite resins should be 😕

a. 10 sec

b. 40 sec

c. 5 sec

d. 20 sec

36 / 60

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

a. Condensation silicone

b. Polysulfied

c. Polyether

d. Polyvinyl siloxane

37 / 60

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

a. Springiness

b. Toughness

c. Hardness

d. Brittleness

38 / 60

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

a. Gold alloy

b. Ceramic

c. Silver alloys

d. Amalgam

39 / 60

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

a. High strength

b. Esthetics

c. Amalgam

d. Ease of casting

40 / 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

41 / 60

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

a. Gold

b. Ceramic

c. Waxe

d. Glass ionomer

42 / 60

Impression compound is characterized by 😕

a. Crystalline in nature with high thermal conductivity

b. Amorphous in nature with high thermal conductivity

c. Crystalline in nature with definite melting point

d. Amorphous in nature with low thermal conductivity

43 / 60

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

a. Water

b. Quartz

c. Gypsum

d. Silica

44 / 60

Commonly used coloring agent in impression plaster is 😕

a. Indigo dye

b. Alizarin red

c. Metallic oxide

d. Congo red

45 / 60

Which of the following is called periphery wax ?

a. Utility wax

b. Beading wax

c. Bite registration wax

d. Sticky wax

46 / 60

Binder in the phosphate investment is 😕

a. Magnesium oxide and monoammonium phosphate

b. Phosphoric acid

c. Manganese dioxide

d. Cristobalite

47 / 60

The catalyst used for condensation silicones is 😕

a. Lead dioxide

b. Stannous octoate

c. Oleic acid

d. Platinum

48 / 60

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

a. Reactors

b. Fillers

c. Retarders

d. Accelerators

49 / 60

Passiveness of chrome cobalt alloys is due to formation of 😕

a. Ferric oxide

b. Cobalt oxide

c. Chromium oxide

d. Chromium carbide

50 / 60

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

a. Is the oldest luting agent

b. Has an obtudant effect on the pulp

c. The least irritant to the pulp

d. Is used as a permanent restorative material in adults

51 / 60

Zinc oxide eugenal impression should be removed from oral cavity :

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

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

c. Exactly after four minutes after kneading

d. When the material is glossy

52 / 60

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

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

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

c. Light from an argon laser will activate polymerization.

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

53 / 60

The reason for hydroxyapatite coating on implant biomaterials is 😕

a. Prolonged healing time

b. Presence of fibrous tissue

c. Greater bony opposition

d. Lesser bony apposition

54 / 60

Acrylic resins are used in which of the following ?

a. Anterior onlays

b. Posterior inlays

c. Denture bases

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

55 / 60

The most commonly employed alloy combination for use in implants is 😕

a. Platinum-aluminum-vanadium alloy

b. Titanium-molybdenum-vanadium alloy

c. Titanium-aluminum-vanadium alloy

d. Titanium-platinum-aluminum alloy

56 / 60

The main ingredient of casting waxes is 😕

a. Gum dammar

b. Candellila wax

c. Paraffin wax

d. Carnauba wax

57 / 60

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

a. A cover over the mixing arms on a triturator

b. Mixing in a mortar and pestle

c. Triturating precapsulated alloy and mercury

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

58 / 60

The light-cured restorative resins have advantages over chemically activated restorative resins as 😕

a. It takes more time for curing

b. It has not more working time available

c. It is more sensitive to oxygen inhibitors

d. It has more working time available

59 / 60

The fluoride release from glass ionomer cement is 😕

a. 0.75 mg during the first week

b. 0.0005 mg during the first month

c. 0.075 mg during the first month

d. 0.005 mg during the first week

60 / 60

The byproduct in condensation silicones is 😕

a. Butyl alcohol

b. Propyl alcohol

c. Methyl alcohol

d. Ethyl alcohol

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The average score is 85%

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