Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Tim's Cards > Dental Materials Part II, Test II > Flashcards

Dental Materials Part II, Test II Flashcards

1
Q

Name 4 advantages to Glass Ionomers

A

Inherent (chemical) adhesion to tooth

Fluoride release

CTE - Coefficient of thermal expansion is similar to tooth

Biocompatible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What does RMGI stand for?

What are 2 important characteristics of RMGI?

A

Resin-modified Glass Ionomer

Acid-base rxn

light and/or chemical cure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the 3 phases of the Conventional Setting Reaction in Glass Ionomers?

A

Ion-leaching

Hydrogel

Polysalt-Gel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is formed in the Ion-Leaching phase of a conventional setting rxn for Glass Ionomers?

Name 2 importanat characteristics of this product:

A

NaF

Not native to Matrix

Physical properties aren’t affected by depletion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the 2 types of rxn going on in the Setting of RMGI?

A

Acid-Base Rxn - traditional glass-ionomer
(proceeds more slowly)

Free-radical polymerization
(similar to composites - light/chemical initiated)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are 3 properties of the Fluoride Release from Glass Ionomers?

A

Rapid Early

Slow, long term

Doesn’t affect physical properties (also doesn’t take part in matrix formation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How long does the initial burst of Fluoride Release from Glass Ionomers last?

A

1-2 Days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The uptake and re-release process process that maintains Fluoride reservoirs can be supplemented with what?

A

Topical fluorides

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

In a glass ionomer, the Fluoride reservoir in the reservoir is _____ the initial burst.

A

A fraction of

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What type of restoration cannot be used with RMGI - Resin Modified Glass Ionomers?

A

Non-Reinforced All-Ceramics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

2 examples of an Elastic Impression Material:

What type are they?

A

Agar and Aginate

Aqueous hydrocolloids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Describe the Syneresis process that occurs with Aqueous Hydrocolloids:
(3 things)

A

Fibril cross linking

Contracts

Exudes water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the primary disadvantage to Alginate?

A

Single cast only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the Advnatages to Addition Silicones?

A

Multiple casts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How does Polyether compare in stiffness to Addition Silicone?

A

Polyether > Addition Sillicone

*Polyether is the most rigid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

List 5 Impression materials from the most to least rigid:

A

Polyether > Addition Silicone > Condensation Silicone > Polysulfide = Hydrocolloids

*Polyether most difficult to get out of pt’s mouth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Why Amalgam? - 5 reasons

A

Inexpensive

Easy to use

Proven (more than 100 years)

Familiarity

Resin-free (less allergies than composite)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are 2 important functions of Cu in Amalgam?

A

Ties up tin by reducing Gamma-2 formation

Reduces creep by reducing marginal deterioration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What does Zinc do for the other elements in Amalgam?

*How?

A

Decreases oxidation

*by sacrificial anode

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

If Amalgam is a brick wall, what fills the holes/voids of the cement?

A

Sn8Hg - Gamma 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

In an admixed high-copper alloy, what is added to the eutectic?

A

Copper

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Gamma 1:

A

Ag2Hg3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q 
T/F
Gamma 1 (Ag2Hg3) surrounds eta phase (Cu6Sn5) and gamma alloy particles (Ag3Sn)
A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q 
T/F
Gamma sphere (Ag3Sn) with epsilon coating (Cu3Sn)

Ag and Sn dissolve in Hg

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Formula for Single Composition High-Copper Alloys

A

Ag3Sn + Cu3Sn + Hg > Ag3Sn + Cu3Sn + Ag2Hg3 + Cu6Sn5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

In the SCS - Single Composition Spherical method of adding Copper to Amalgam, the less the condensation force, the ________.

A

Larger the Condenser

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

T/F

Most high-copper amalgams undergo a net contraction

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What do high-copper amalgams leave once they have contracted?

What does this cause?

A

Marginal gap

Initial leakage and post-op sensitivity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

T/F

High-copper amalgams will have reduced corrosion over time

A

True

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What does the net contraction of Amalgams depend on?

3 things

A

Type of alloy

Condensation technique

Trituration time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What type of alloy has more contraction?

A

Spherical

less mercury

32
Q

Greater condensation =

A

Higher contraction

33
Q

What does overtitration cause in an amalgam?

A

Higher contraction

34
Q

What type of Strength do amalgams have?

A

Higher compressive vs. Tensile

35
Q

T/F

Corrosion reduces strength of Amalgam

A

True

36
Q

What are the 2 ways Corrosion will seal margins
Low copper?
High copper?

A

Low Cu: 6 months (SnO2, SnCl - gamma 2 phase)

High Cu: 6-24 months (SnO2, SnCl, CuCl - eta-phase Cu6Sn5)

37
Q

Creep correlates with what?

A

Marginal Breakdown

38
Q

How much Cu must be in amalgam before it can preven the Gamma-2 phase and have Creep Resistance?

A

12% Cu total

39
Q

Overtrituration will have what 3 effects?

A

“hot” mix - sticks to capsule

Decreases working/setting time

Increases setting contraction

40
Q

Undertituration will create what kind of mix?

A

Grainy, crumbly

41
Q

What does Condensation of Amalgam do to Hg?

A

Reduces residual Hg in restoration

***this is what happens when packing preparation

42
Q 
T/F
Condensation is:
A continuation of trituration
Adapts amalgam to cavity walls
REduces residual Hg in restoration
Eliminated voids
Increases strength and servicability to restoration
A

True

43
Q

T/F
Dentists can specialize in treating purported Hg toxicity, and the removal of amalgam supposedly cures Leukemia, Hodgkin’s disease, and MS

A

True

44
Q

T/F

The lay population is unfamiliar with peer reviewed dental lit and relies on media/internet to get it right

A

True

45
Q

How many Amalgam Restorations are there/yr?

A

1/2 Billion

*75 tons of Hg

46
Q

T/F

Mercury vapor is released by chewing/brushing and it is difficult to determine vapor levels accurately

A

True

47
Q

What is the average daily dose of Mercury from 8-10 amalgam surfaces?

What is the threshold level?

A

1-2 micrograms/day

50 micrograms/day

82 considered dangerous

48
Q

Less than _____ % of elemental Mercury can be absorbed from the GI and the skin

A
  1. 1%

* also non-toxic if swallowed

49
Q

T/F

Mercury vapor from spills (thermometers, fluorescent light bulbs) accountf for most exposure

A

True

50
Q

What is the most toxic form of Mercury?

Where is it absorbed?

A

Methylated

95% absorbed in gut

*Minamata Bay - Hg methylated by marine animals and concentrated up food chain

51
Q

Blood can reflect ______ of Hg

A

Recent exposure

52
Q

What is the half life of Hg in the blood

A

3 day

53
Q

T/F

Hair is a reliable method for Hg monitoring

A

False

54
Q

T/F

Studies found no relationship between Amalgam and MS

A

True

55
Q

T/F

Studies have linked Hg from amalgam Hg to Hg found in Alzheimersf

A

False

*no link established

56
Q

T/F

Studie show Renal Toxicity due to Amalgam restorations

A

False

57
Q

T/F
Changing the Powder/Liquid ration will have a profound effect on Film Thickness and Consistency when it comes to cements, liners, and bases

A

True

58
Q

What determines the Ultimate Film Thickness in Cements?

5 components

A

Particle size of powder

Conc. powder in liquid

Liquid viscosity

Cement consistency

Force applied at cementation

59
Q

What 2 factors influence the ease with which cement is expressed from under the restoration?

A

Consistency of cement

Type of restoration

60
Q

T/F

Self etching has no Etch and Rinse - all 3 components, the Etch, Primer, and Bonding Agent are combined

A

True

61
Q

T/F

Etch and Rinse are generally 3 step or 2 step process

A

True

62
Q

A 3 Step Etch and Rinse would be a ______ Generation

A

4th

1 - etch and Rinse

2 - Primer

3 - Bonding/Adhesive agent

63
Q

5th Generation 2 step has what 2 steps?

A

1 - Etch and Rinse

2 - Primer/Adhesive mixture

64
Q

T/F

Self-etching can be 1 or 2 steps

A

True

65
Q

Self Etching: conditioner, etch, and primer all mixed and either 1:

or 2:

A

1: Bonding incorporated (1 step)
2: Etch and Primer mixed, Then mix Adhesive (2 steps)

66
Q

With the exception of _________, most bonding is _______

A

Glass-ionomer

Micro-mechanical

67
Q

Bonding to dentin locks into micropores created when etched - collagen fibers and dentinal tubules

A

True

68
Q

Most anything bad about restorations is due to amount of polymer

A

True

69
Q

More fillers, less matrix

Less fillers, more matrix

A

Microhybrid

Microfill

70
Q

Biggest problem with polymerization shrinkage?

A

Bond failure at Interface

71
Q

Gamma:

Gamma 1:

Gamma 2:

A

Ag3Sn (bricks)

Ag2Hg3 (cement)

Sn8Hg (void filler in cement)

72
Q

Cu added to Epsilon by:

Cu added to Silver-copper eutectic by:

A

Gamma (Ag3Sn), Ag and Sn dissolve in Hg

Spherical - Ag enters Hg from Ag-Cu spherical eutectic particles

73
Q

Urine Hg testing for:

Blood Hg testing for:

A

chronic

acute

74
Q

Composites, Cu ionomers, Glassionomers, RMGI

which has the most F?

A

Similar for Conventional Glass-Ionomers and RMGI

75
Q

T/F
Higher conc. of Cu reduces the Gamma-2 formation that reduces creep and corrosion and doesn’t react with Hg because it attracts tin

A

True

76
Q

Which phase of amalgam is the weakest?

A

Gamma 2

Tim's Cards (140 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions