Biomaterial Test

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Biomaterial Test

1 / 60

The chemistry behind the condensation of the amalgam is to 😕

a. To reduce gamma II particules

b. Condense the unattacked gamma particles

c. Condense the unattacked gamma II particles

d. Condense the unattacked gamma I particles

2 / 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. Chemical bonding

d. High malleafility of metal

3 / 60

The type of stress to which dental amalgam is more resistant to 😕

a. Tensile stress

b. Impact stress

c. Compressive stress

d. Shear stress

4 / 60

Condensation of porcelain is done by all the methods except 😕

a. Spatulation method

b. Brush addition technique

c. Vibration method

d. Ceramming method

5 / 60

The gelation temperature of agar hydrocolloid impression material should be 😕

a. 100C higher than mouth temperature

b. 37-450C

c. 45-600C

d. Far below the oral temperature

6 / 60

The physical properties most desirable in set amalgam are which of the following ?

a. Higher strength, low creep, low corrosion

b. Higher strength, high creep, low corrosion

c. Low strength, low creep, low corrosion

d. Higher strength, high creep, high corrosion

7 / 60

Commonly used filler in composite is 😕

a. Colloidal silica

b. Quartz

c. Aluminum

d. Glass

8 / 60

Resistance of a liquid to motion is called 😕

a. Springiness

b. Diffusion

c. Viscosity

d. Creep

9 / 60

Chemically cured resin shrinks:?

a. Away from the light source

b. On the base only

c. On the surface only

d. Towards the center of bulk of material

10 / 60

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

a. Amalgam scrap stored in a closed container

b. Baseboard heating

c. Floor carpeting

d. fluorite release

11 / 60

Distortion on removal from undercuts in addition silicones is very less due to 😕

a. Lowest strain in compression

b. Shrinkage of material

c. Stiffness of the material

d. Increased strain rate on unset material

12 / 60

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

a. Unfilled acrylic resin

b. Glass ionomer cement

c. Composite resin

d. Silicate cement

13 / 60

Acrylic resins are used in which of the following ?

a. Anterior onlays

b. Denture bases

c. Posterior inlays

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

14 / 60

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

a. All are correct

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

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

d. Microfilled

15 / 60

Dental porcelains are manufactured by a process termed as 😕

a. Fusing

b. Sintering

c. Fritting

d. Vulcanizing

16 / 60

Which of the following materials are used for dental implants ?

a. Gold alloys

b. Metal alloys

c. Cobalt and chromium alloys

d. Titanium

17 / 60

Most commonly used pit and fissure sealant is 😕

a. Bis-GMA resin

b. Polyurethane

c. Filled acrylic

d. Unfilled acrylic

18 / 60

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

a. Wall carpeting

b. Floor carpeting

c. Amalgam scrap stored in a closed container

d. Baseboard heating

19 / 60

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

a. Polyether

b. Polysulfide

c. Addition silicone

d. Condensation silicone

20 / 60

Porcelain denture teeth 😕

a. Are easy to grind and polish

b. Have higher coefficient of thermal expansion than resin teeth

c. Are more resistant of abrasion than gold

d. Have decreased abrasion resistance than dentin

21 / 60

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

a. Restoration should be build in increments

b. Cured for longer period

c. Not indicated

d. Fifth generation bonding agent should be applied

22 / 60

Metal has the following properties except 😕

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

b. Electroplated silver and copper are used in dies

c. Pure metals are not useful in dentistry

d. Metal is any element that ionizes positively in solution

23 / 60

The reason for hydroxyapatite coating on implant biomaterials is 😕

a. Presence of fibrous tissue

b. Prolonged healing time

c. Greater bony opposition

d. Lesser bony apposition

24 / 60

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

a. Is combined primarily with silver

b. Has the toxic properties of unreacted mercury

c. Composite restorative resins

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

25 / 60

For each property, list the amalgam type (irregular low-copper, admixed high-copper, and spherical high-copper ) that has the highest value?.

a. Creep irregular low-copper

b. 1-hour compressive strength spherical high-copper

c. Creep irregular high-copper

d. Tensile strength spherical high-copper

26 / 60

Which of the following composites give rough surfaced finish ?

a. Microfilled composites

b. Hybrid composites

c. Conventional composites

d. Small particle filled composites

27 / 60

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

a. Carding wax

b. Beading wax

c. Boxing wax

d. Utility wax

28 / 60

Higher mercury left in an amalgam leads to which of the following ?

a. High corrosion

b. Low corrosion

c. Higher strength

d. Higher creep

29 / 60

Which of the following components acts as a refractory material in porcelain ?

a. Feldspar

b. Potash

c. Silica

d. Kaolin

30 / 60

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

a. Base plate wax

b. Utility wax

c. Sticky wax

d. Carding wax

31 / 60

Which of the following is called periphery wax ?

a. Bite registration wax

b. Sticky wax

c. Beading wax

d. Utility wax

32 / 60

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

a. Oxide

b. Gamma I Phase

c. Sulphide

d. Gamma II Phase

33 / 60

Commonly used viscosity controller in composites is 😕

a. Methyl methacrylate

b. TEG-DMA

c. Bis-GAM

d. Polyurethanes

34 / 60

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

a. Triturating precapsulated alloy and mercury

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

c. A cover over the mixing arms on a triturator

d. Mixing in a mortar and pestle

35 / 60

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

a. Polyethers

b. Addition silicones

c. Polysulfides

d. Condensation silicones

36 / 60

Conventional dental amalgam alloy contains 😕

a. Silver, tin, palladium and zinc

b. Silver, mercury, copper and zinc

c. Silver, mercury, copper and mercury

d. Silver, tin, copper and zinc

37 / 60

In UV curing system the activator employed is 😕

a. Methyl methacrylate

b. Benzoin methyl ether

c. Hydroquinone

d. Dibutyl phthalate

38 / 60

Ideally, the set amalgam should do which of the following ?

a. Shrink significantly to provide space for correction products to seal the margins

b. Expand greatly to provide marginal seal against the tooth

c. Properties of amalgam

d. Have little dimensional change

39 / 60

Most common use of Zinc oxide eugenol paste 😕

a. Wash impression for edentulous patients

b. As interocclusal record material

c. Surgical paste

d. Dual impression for Partially edentulous patients

40 / 60

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

a. 3:1

b. 1:2

c. 2:1

d. 1:3

41 / 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

42 / 60

The tendency of stainless steel to break under repeated condition of cyclic stressing below the ultimate strength is 😕

a. Resilience

b. Fatigue

c. Ductility

d. Creep

43 / 60

Impression compound is characterized by 😕

a. Amorphous in nature with low thermal conductivity

b. Crystalline in nature with high thermal conductivity

c. Amorphous in nature with high thermal conductivity

d. Crystalline in nature with definite melting point

44 / 60

For proper wetting, contact angle should be ideally 😕

a. 900

b. 600

c. 450

d. 00

45 / 60

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

a. Porcelain will not bond with metal

b. Porcelain will wear off

c. Porcelain will crack on cooling

d. Porcelain will provide good shade

46 / 60

Which of the composites with the following fillers may be radiopaque ?

a. Barium glass

b. Colloidal silica

c. Lithium aluminum silicate

d. Quartz

47 / 60

Which of the following composite is recommended for non stress bearing anterior restoration ?

a. Conventional composites

b. Microfilled composites

c. Hybrid composites

d. Small particles

48 / 60

Adhesion in composites is due to 😕

a. Presence of smear layer

b. Cohesion

c. Mechanical interlocking

d. True chemical bonding to tooth structure

49 / 60

Regarding Knoop hardness number, which of the following material is closest to that of dentine (KHN 65) ?

a. Pure gold

b. Amalgam

c. Composites

d. Silicates

50 / 60

A small portion of an anterior tooth would most likely be restored with which of the following ?

a. Gold alloy

b. Amalgam

c. Porcelain

d. Composite resin

51 / 60

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

a. Heat temperature

b. Vapor temperature

c. Fusion temperature

d. Temperature of specificity

52 / 60

Which of the following statements about laboratory composites are true ?

a. Fiber reinforcement increases their strength but decrease their rigidity.

b. Restorations prepared from laboratory composites typically are cemented with zinc phosphate cement.

c. Curing using light, heat, and pressure increase the wear resistance.

d. Bridge prepared from laboratory composites require a metal substructure.

53 / 60

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

a. Type I

b. Type II

c. Type IV

d. Type III

54 / 60

Nickel in base metal alloys increase its 😕

a. Hardness and fusion temperature

b. S Ductility

c. Strength

d. Modulus of elasticity

55 / 60

Impression plaster is a 😕

a. Reversible impression material

b. Mucostatic material

c. Mucocompressive material

d. Thermoplastic material

56 / 60

Binder in the phosphate investment is 😕

a. Cristobalite

b. Manganese dioxide

c. Phosphoric acid

d. Magnesium oxide and monoammonium phosphate

57 / 60

All are properties of waxes except 😕

a. Plastic deformation

b. Creep

c. Flow

d. Solidification shrinkage

58 / 60

The cavity for a GIC restoration is preconditioned with 😕

a. Polyacrylic acid for 60 seconds

b. Polyacrylic acid for 10 seconds

c. Phosphoric acid for 10 seconds

d. Phosphoric acid for 60 seconds

59 / 60

In alginate impression the final gel is 😕

a. Sodium sulphate

b. Sodium alginate

c. Calcium sulphate

d. Calcium alginate

60 / 60

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

a. Fillers

b. Accelerators

c. Reactors

d. Retarders

Your score is

The average score is 36%

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