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Flashcards in Materials Midterm Deck (61)
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1
Q

Alloy

A

Combination of two or more metals

2
Q

What material has been used for over 150 yrs

A

Amalgam

3
Q

What type of restoration is glass ionomer used for

A

Primary teeth, final restorations in non stressed areas, sealants, core material for build ups, provisional restorations

4
Q

IRM

A

Intermediate restorative material: short term restoration like zinc oxide Eugenol composition

5
Q

Material that is still pliable when applied to teeth is what kind of restoration

A

Direct

6
Q

Indirect restoration

A

A restoration fabricated outside the mouth by a lab tech

7
Q

Where are indirect restorations made

A

In a lab

8
Q

Liquids with high viscosity are not effective in what

A

Wetting a surface

9
Q

Tensile stress

A

Pulls and stretches (tug of war)

10
Q

Compressive stress

A

Pushes material together (chewing)

11
Q

Shear stress

A

Sliding

12
Q

How many mg are in a single capsule of amalgam

A

600 for small 800 for large

13
Q

What type of restorations use amalgam

A

1,2,5 for direct

14
Q

What is done with an amalgam capsule after mixing is complete

A

Placed in wide mouth airtight container labeled

15
Q

Amalgamation

A

Mercury and alloy are mixed

16
Q

How is curing time influenced for a composite restoration

A

Thickness and size of restoration, shade of material, manufacturers instructions

17
Q

Advantage of using glass ionomer

A

Fluoride release, adhesion, resistance to acid erosion, strong, biocompatible with oral enviro, inhibits decay

18
Q

Macrofilled composites

A

Conventional/traditional composite that contains large amounts of filler particles and provides strength

19
Q

How many pounds per square inch does a posterior restoration need to withstand

A

170 pounds 28,000?

20
Q

What metals make up alloy

A

Silver, zinc, tin, copper

21
Q

What does silver do

A

Strength

22
Q

What does tin do

A

Workability and strength

23
Q

What does copper do

A

Strength and corrosion resistance

24
Q

What does zinc do

A

Suppress oxidation

25
Q

What is corrosion

A

Reaction that occurs within metal when exposed to temp, humidity, and saline

26
Q

How is corrosion removed

A

Polishing agents

27
Q

What is a non Mercury alloy

A

Galloy: composed of gallium, indium, and tin (gallium)

28
Q

What is used to ensure accurate ratios of alloy and Mercury

A

Eames technique 1:1

29
Q

What does properly triturated amalgam look like

A

Soft, pliable, and easily shaped

30
Q

What type of cement used as adhesive for permanent indirect restorations

A

Type 1: luting agent (glass ionomer, ZOE, poly carboxylate, zinc phosphate)

31
Q

How should cements be dispensed when there is powder to liquid involved

A

Powder and liquid on opposite sides, In increments, smallest first

32
Q

When would u use temp cement

A

When u need temp coverage until perm restoration is ready or patient is in pain and something is needed

33
Q

What might happen if there is a delay in mixing and placing of indirect restoration

A

Result in initial setting process causing casting to not seat right

34
Q

What cement gives of exothermic heat

A

Zinc phosphate

35
Q

How is cement placed in an indirect restoration for delivery

A

Line surface

36
Q

What kind of cement is less sensitive to the pulp than zinc phosphate

A

Polycarboxlyate

37
Q

Which type of glass ionomer is used to restore areas or erosion near gingiva

A

Type 2

38
Q

Which type of cement would be used for cement action of ceramic veneers

A

Composite resin

39
Q

What can occur if cement is left around margins of the crown

A

Cement can irritate the area and cause inflammation and discomfort

40
Q

What can influence cementation procedure

A

Mixing time, humidity, powder to liquid ratio, temp

41
Q

What should a provisional restoration be filled with when being placed for temp coverage

A

Luting cement

42
Q

How does polycarboxlyate appear once setting has initiated

A

Loss of glossiness is stringy or weblike

43
Q

If more time is needed for mixing of a cement what can be used

A

A glass slab

44
Q

What cement is irritating to the pulp and most acidic

A

Zinc phosphate

45
Q

What is an impression

A

Negative reproduction of the mouth

46
Q

What material used first with elastomeric impression

A

Light bodied

47
Q

3 classifications of impressions

A

Preliminary, final, occlusal (bite registration)

48
Q

What is made from preliminary impression

A

diagnostic models, custom trays, provisional coverage, orthodontic appliances, pretreatment/post treatment records

49
Q

How much material should fit between tray and edges of teeth

A

2-3mm

50
Q

What does an impression become after poured in plaster

A

A positive

51
Q

What irreversible hydrocolloid is used most widely for preliminary impressions

A

Alginate

52
Q

How quickly should alignate impression be poured up

A

Within 1 hour of taking impression

53
Q

Imbibition

A

Absorption of water causing object to swell

54
Q

Syneresis

A

Loss of water causing to shrink

55
Q

How do u alter setting time of irreversible alignate

A

Using cool water

56
Q

What is the elastomeric material with highest viscosity

A

Putty

57
Q

What can an automix system for elastomeric impression material do

A

Automatically mixes and dispenses used with light and heavy body

58
Q

3 curing stages for impression materials

A

Initial set, final set, final cure

59
Q

How does water affect alignate impression mix

A

Alter setting time

60
Q

What is the most viscous reversible hydrocolloid

A

Tray material/heavy bodied

61
Q

3 classifications for impression materials

A

Irreversible and reversible hydrocolloid and elastomeric