Dental Materials Flashcards Preview

d.b.review 2 > Dental Materials > Flashcards

Flashcards in Dental Materials Deck (83)
Loading flashcards...
1
Q

Inelastic impression

A

Plaster of paris aka impression plaster or type I stone

2
Q

Elastic impressions (4)

A

Colloidal solutions
ZOE
Impression compounds
Elastomers

3
Q

Reversible hydrocolloids are ____ from seaweeds

And is used with specialized equipments**

A

Agar-agar

4
Q

Reversible hydrocolloids impt properties (3)

A

Imbibition
Syneresis
Hysteresis

5
Q

Absorbs water

A

Imbibition - expansion

6
Q

Releases water

A

Syneresis - syrink

7
Q

Ability of material to change its form based on temperature

A

Hysteresis

8
Q

Liquefaction temp

A

Gel to sol

9
Q

Gelation temp

A

Sol to gel

10
Q

Reversible hydrocolloid composition (2)

A

Water

Agar

11
Q

Principal content of reversible hydrocolloid

A

Water 85%

Agar is 15% only mixed with BORAX (hardener)

12
Q

Component of irreversible hydrocolloids (4)

A

Sodium alginate or K alginate
Ca sulfate
Diatomaceous earth
NaPO4

13
Q

Major reactor of irreversible hydrocol

A

Sodium alginate or K alginate

14
Q

Principal component of irreversible hydrocol

A

Diatomaceous Earth

Made from SILICA *

15
Q

Flexites are made from

A

Nylon

16
Q

ZOE contains

A

Oil of cloves

17
Q

Contraindic for zoe (2)

A

Resins

Cavity varnish

18
Q

Most common technique to soften impression compound

A

Dry heat

Water bath another one :)

19
Q

First invented elastomer with the longest setting time

A

Polysulfide

20
Q

Base and catalyst of polysulfide

A

Base - mercaptan

Catalyst - lead peroxide (causes foul and stains)

21
Q

Least dimensionally stable among elastomers

A

Condensation silicones

22
Q

Most dimensionally stable among elastomers

A

Addition silicones

23
Q

Silicones
Powder/filler:____
Catalyst:____

A

Silica

Tin octoate

24
Q

Polyether
Base:___
Catalyst:____

A

Polyether

Alkyl-aromatic sulfonate

25
Q

Dehydrate form of gypsum

A

Calcium sulfate hemihydrate

26
Q

Plaster of paris aka

A

Beta calcium sulfate hemihydrate

27
Q

Type I plaster of paris

A

Impression plaster

28
Q

Type II plaster of paris

A

Model plaster or study cast

29
Q

Type IV gypsum

A

High strength stone (die stone)

30
Q

Type III gypsum

A

Dental stone or alpha calcium sulphate hemihydrate

31
Q

Gypsum retarder (2)

A

Borax

Na citrate

32
Q

Gypsum accelerator (3)

A

Gypsum
Potassium sulfate
Sodium chloride

33
Q

Investment for cast gold

A

Gypsum bonded investment

34
Q

Imvestment for cast cobalt chromium

A

Phosphate bonded investment

35
Q

Wax for bite wax

A

Corrective wax

36
Q

Wax for boxing wax sticky wax and utility wax

A

Processing wax

37
Q

Wax for inlay crowns rpd wax casting wax

A

Pattern wax

38
Q

Natural waxes used in dental waxes are (3)

A

Paraffin
Beeswax
Carnauba

39
Q

Tendency of molecule to expand or shrink depending on the temp

A

Coef of thermal expansiom

40
Q

Best way to prevent warpage of patterns is to

A

Invest immediately

41
Q

Best thing to do preserve dimension

A

Refrigerate - shrink place room temp then invest

42
Q

Principal component of pattern waxes

A

Paraffin

43
Q

Hardest structure in the world

A

Diamond

44
Q

High noble aka
Content (2)
Examples (4)

A

Precious metal
>=60% noble metal
>=40% gold

Silver
Platinum
Palladium
Titanium

45
Q

Noble aka

Content???

A

Semiprecious

>=25% noble

46
Q

Base dental alloy aka

Content

A

Non-precious

<=25%

47
Q

Hardest component used in dent (3)

A

Porcelain
Gold
Acrylic

48
Q

Resistance to breaking under compressiom

A

Compressive strength

49
Q

Resistance to breaking under tension

A

Tensile strength

50
Q

Resistance to breaking or slide under horizontal forces

A

Shear strength

51
Q

Max stress before fracturing

A

Ultimate tensile strength

52
Q

Most important, resistance to permanent deformation

A

Yield strength

53
Q

Rigidity or stiffness

A

Modulus of stiffness

54
Q

Important for wear characteristics and finishing

A

Hardness

55
Q

Change in length per 1 degree celcius change in temp

A

CTE

56
Q

Process of joining two piece metal together through the use of lower fusing intermediate metal

A

Solder

57
Q

Fusion temp p

A

100-150 degree F

58
Q

Optimal space for solder

A

0.25 mm

59
Q

Added to metal to improve flow of solder, dissolves oxides and prevent contaminatiom

A

Flux

60
Q

Placed around the area that is to be soldered to restrict flow

A

Antiflux

61
Q

Flame with excessive oxygen that produces oxide

A

Oxidizing

62
Q

Flame with low oxygen. That produces carbon in metal

A

Reducing

63
Q

Flame with balance oxygen levels

A

Neutral

64
Q

Most common anti flux

A

Soft graphite pencil

65
Q

Flame best to use with cast gold resto

A

Blue correct

Boards is REDUCING FLAME

66
Q

Exposure of walls of prep to a fluid

A

Percolation

67
Q

Principal component of dental porcelain

A

Feldspar

68
Q

Act as matrix in dent porcelain

A

Feldspar

69
Q

Provides skeleton and strength

Filler of porcelain

A

Quartz

70
Q

Clay that acts as a binder opaquer and flux

A

Kaolin

71
Q

Properties of dental porcelain (2)

A

CS> tensile or shear

Low plastic deformation

72
Q

Saturation of hue

A

Chroma

73
Q

Lightness or whiteness or darkness or blackness

A

Value

74
Q

Actual color

A

Hue

75
Q

Other component of ZOE that increases strength

A

Ethoxy benzoic acid

76
Q

First cement that bond to tooth structure

Faster setting than zinc phosphate

A

Zinc polycarboxylate

77
Q

Powder and liquid of zn phosphate cement

A

Zinc xodie

Orthophoshoric acid

78
Q

Only cement that is basic

A

CaOH

79
Q

Most soluble cement

A

Silicate

80
Q

Least soluble cement

A

gi cement

81
Q

First cement to the release fluoride

A

Silicate cements

82
Q

GIC principal fluid

A

Polyacrylic acid

83
Q

Zinc silicophosphate powder and liquid

A

Zinc phosphate and silicate

Phosphoric acid