Biomaterial Test

5 votes, 5 avg

164

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Biomaterial Test

1 / 60

A glaze is placed over the finished composite restoration to 😕

a. To change the shade

b. No provide a better peripheral seal

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

d. To reduce surface porosities

2 / 60

The function of gum dammar in inlay wax is 😕

a. No resistance to carving

b. To improve smoothness of pattern

c. No smoothness of pattern

d. Less strength to wax

3 / 60

The byproduct in condensation silicones is 😕

a. Butyl alcohol

b. Propyl alcohol

c. Methyl alcohol

d. Ethyl alcohol

4 / 60

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

a. Ag-Sn

b. Cu-Sn

c. Ag-Hg

d. Sn-Hg

5 / 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

6 / 60

The reason zinc oxide eugenol cement is used as a temporary restoration 😕

a. It has poor tensile strength

b. It does not have anticariogenic activity

c. It has an obtudant effect

d. It does not form reparative dentin

7 / 60

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

a. Accelerators

b. Retarders

c. Fillers

d. Reactors

8 / 60

Softening of impressing compound is best accomplished by 😕

a. Dry heat

b. Water bath

c. Oil bath

d. Open flame

9 / 60

Porcelain-bonded to metal is stronger when fired 😕

a. Under compression

b. Under low temperature

c. After metal is tempered

d. Several times in air

10 / 60

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

a. High corrosion

b. Higher strength

c. Low corrosion

d. Higher creep

11 / 60

In UV curing system the activator employed is 😕

a. Dibutyl phthalate

b. Benzoin methyl ether

c. Methyl methacrylate

d. Hydroquinone

12 / 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

13 / 60

Strength of dental porcelain is dependent on 😕

a. No internal structure

b. Composition

c. Rough

d. Resistance to fusion

14 / 60

Glass ionomer cenment is not recommended for 😕

a. Class V restoration

b. Class IV resoration

c. Class I restoration

d. Class III restoration

15 / 60

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

a. Latent heat

b. Fusion temperature

c. Specific temperature

d. Temperature of vaporization

16 / 60

Greening effect of porcelain is due to 😕

a. Palladium

b. Silver

c. Golde

d. Platinum

17 / 60

Main disadvantage of laminate technique of making impression is : ?

a. Bond between agar and alginate is not very strong

b. Maximum details are not produced

c. Cost factor is high

d. Difficult to manipulate

18 / 60

Porosity in denture base resins can be due to 😕

a. Adequate mixing of liquid and powder components

b. Well flasking of wax pattern

c. Excess heating of resin above its boiling point

d. Applying sufficient pressure during polymerization

19 / 60

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

a. Barium glass

b. Colloidal silica

c. Quartz

d. Lithium aluminum silicate

20 / 60

Dental porcelains are manufactured by a process termed as 😕

a. Fusing

b. Sintering

c. Vulcanizing

d. Fritting

21 / 60

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

a. 1-hour compressive strength spherical high-copper

b. Creep irregular low-copper

c. Creep irregular high-copper

d. Tensile strength spherical high-copper

22 / 60

Thickness of the gel between the tray and tissue for either agar or alginate should always be at least 😕

a. 1 mm

b. 2 mm

c. 3 mm

d. 4 mm

23 / 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

24 / 60

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

a. Shrinkage of material

b. Stiffness of the material

c. Increased strain rate on unset material

d. Lowest strain in compression

25 / 60

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

a. Vichers hardness test

b. Knoop hardness test

c. Brinell hardness test

d. Rockwell hardness test

26 / 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

27 / 60

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

a. Microfilled

b. All are correct

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

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

28 / 60

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

a. They are attached to natural teeth with cements,

b. Carbone steal

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

d. Artificial waxes teeth are attached

29 / 60

Which of the following statements about compomers are true ?

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

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

c. They typically are recommended for class II restorations.

d. They also are know as GIC

30 / 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

31 / 60

Amalgam is less prone to corrosion 😕

a. If it contains 4-6% of copper

b. If devoid of the gamma 2 phase

c. If it contains 25-27% of tin

d. If it contains zinc

32 / 60

Minimum light exposure time for composite resins should be 😕

a. 40 sec

b. 20 sec

c. 10 sec

d. 5 sec

33 / 60

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

a. Base plate wax

b. Carding wax

c. Utility wax

d. Sticky wax

34 / 60

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

a. Silicate

b. Zinc phosphate

c. Direct resin-filling material

d. Amalgam

35 / 60

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

a. Kaolin

b. Feldspar

c. Silica

d. Potash

36 / 60

Full denture bases are usually made from which of the following materials ?

a. Ceramic

b. Acrylic resin

c. Gold alloys

d. Composite restorative resins

37 / 60

All are properties of waxes except 😕

a. Creep

b. Flow

c. Solidification shrinkage

d. Plastic deformation

38 / 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. Triturating precapsulated alloy and mercury

c. Mixing in a mortar and pestle

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

39 / 60

The main advantage of composites compared to silicates cement is 😕

a. Color matching with the tooth structure is excellent

b. Coefficient of thermal expansion close to tooth structure

c. High modulus of resilience

d. Practically insoluble in oral fluids

40 / 60

All of the following are properties of Co-Cr-Ni wires except 😕

a. They cannot be soldered or welded

b. They have excellent tarnish and corrosion resistance

c. Their hardness is comparable to stainless steel

d. They can be heat treated

41 / 60

Biting force in the molar region ranges from 😕

a. 600-1000 N

b. 1000-1300 N

c. 900-1000 N

d. 400-890 N

42 / 60

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

a. Toughness

b. Modulus of elasticity

c. Resilience

d. Flexibility

43 / 60

Nickel sensitivity in the general population is 😕

a. 3% for men

b. 1% in the overall population

c. 11% for women

d. 3% for women

44 / 60

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

a. Gold

b. Ceramic

c. Waxe

d. Glass ionomer

45 / 60

Inorganic phase in a composite matrix 😕

a. Increases coefficient of thermal expansion

b. Increases the mechanical strength

c. Increases the polymerization shrinkage

d. Decreases the mechanical strength

46 / 60

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

a. Hybrid ionomer

b. Compomer

c. Glass ionomer

d. Composite

47 / 60

A portion of a posterior tooth that is subject to high biting forces would likely be restored with which of the following ?

a. Amalgam

b. Acrylic resin

c. Composite resin

d. Glass ionomer

48 / 60

The catalyst used for condensation silicones is 😕

a. Stannous octoate

b. Lead dioxide

c. Platinum

d. Oleic acid

49 / 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 most effective bonding agents contain copalite.

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

d. The use of amalgam bonding restores the strength of the clinical crown to its original condition.

50 / 60

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

a. It is a bio-inert material

b. This material in granular form and is difficult

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

d. It is produced in block or granula form

51 / 60

Calcium hydroxide is used for 😕

a. Reduce maginal leakage

b. To prevent recurrent caries

c. Pulp capping

d. Reinforce the restoration

52 / 60

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

a. Have little dimensional change

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

c. Expand greatly to provide marginal seal against the tooth

d. Properties of amalgam

53 / 60

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

a. Pheyl methacrylate

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

c. Poly (methyl methacrylate)

d. Polystyrene

54 / 60

Setting time of alginate can be better controlled by 😕

a. Mixing time

b. Changing water: powder ratio

c. Temperature of water used of mixing

d. Chemical accelerators and retarders

55 / 60

In dental porcelains metallic oxides provide 😕

a. Color and provides refractile property

b. Color and increases the strength

c. Color but decreases the strength

d. Provides refractile property and increases strength

56 / 60

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

a. Addition silicones

b. Polyether

c. Polysulfides

d. Condensation silicones

57 / 60

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

a. Gold alloy

b. Composite resin

c. Amalgam

d. Metal

58 / 60

Commonly used filler in composite is 😕

a. Quartz

b. Glass

c. Aluminum

d. Colloidal silica

59 / 60

The strain at which the plastic strain develops may be represented by 😕

a. Elastic limit, modulus of elasticity, tensile strength

b. Yield strength, tensile strength, toughness

c. Toughness, rigidity, resilience

d. Elastic limit, yield strength, proportional limit

60 / 60

The main ingredient of casting waxes is 😕

a. Gum dammar

b. Candellila wax

c. Carnauba wax

d. Paraffin wax

Your score is

The average score is 86%

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