Brainscape's Knowledge GenomeTM

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


See full index

Direct Restoration > Lecture 8 > Flashcards

Lecture 8 Flashcards

1
Q

Adhesive joint:

A

A layer of intermediate material (adhesive) with 2 surfaces (adherends) producing 2 adhesive interfaces

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

Tooth structure is generally hydro–

A

hydrophilic

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

composite is generally hydro–

A

hydrophobic

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

2 adhesive interfaces:

A

adhesive and composite, adhesive and tooth structure

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

Year acid etch was put into use, and by whom?

A

1955, Michael Buonocore

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

Ray Bowen discovered what, in what year?

A

Bis-GMA 1962

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

To understand the principles of adhesions we must talk about these parameters:

A

Substrate, adhesive system, mech of adhesion, clinical techniques

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

Enamel is hydro (philic/phobic) compared to composite

A

hydrophilic, bc of the water content

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

Enamel is hydro (philic/phobic) compared to dentin:

A

hydrophobic

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

Enamel is __% mineral by weight, __ % organic, and ___ % water.

A

95, 4, 1

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

What kind of shapes form enamel?

A

prisms

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

How many hyrdoxyapetite crystal form a prism of approx. 5-7 microns?

A

10,000

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

Comp of dentin:

A

70% inorganic, 20% organic (collagen), 10% water

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

What type of substrate is dentin?

A

dynamic substrate, subject to constant physiologic and pathologic changes in composition and microstructure

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

How does the dentin change with age?

A

the relative conc of organic vs. inorganic content, happens with repetitive trauma as well

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

Characteristics of dentin as a substrate:

A

permeable, wet, heterogenous, tubular, mineralized, collagen reinforced with inter and intra-fibrillar apatite

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

Dentinal tubules contain:

A

odontoblasts (1/3 into tubules), fluids, nerve fibers, other molecules in the intracellular matrix

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

2 types of dentin:

A

peritubular and intertubular

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

Peritubular dentin:

A

more mineralized than intertubular, lining of tubule, little organic matrix

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

intertubular:

A

rich in collagen fibers, ideal for hybridization, bulk of dentin

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

Adhesion to tooth structure is primarily:

A

micromechanical

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

T or F? Current adhesive system only employ bonding to hydrophilic substrates.

A

F. both hydrophilic and phobic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Adhesives used to be classified according to:

A

time of appearance into market: generation 1-7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Current classification of adhesives:

A

steps and adhesive strategy (1,2, or 3 steps)/ (etch-and-rinse, self-etch)

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

2 types of adhesive strategies:

A

etch-and-rinse AND self-etch

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

3 steps of dentin/enamel bonding:

A

etch, primer, adhesive

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

etch step is aka:

A

conditioner (typically acid)

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

Fxn of etch step:

A

cleans/preps surface, removes smear layer and mineral

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

What is primer?

A

amphipathic monomers + solvent carrier (has both hydrophilic and phobic carriers), connects philic and phobic

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

Fxn of primer:

A

infiltrates exposed collagen network, displaces moisture and links to hydrophobic adhesives

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

Adhesives are:

A

hydrophobic resin monomers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Fxn of adhesive:

A

link to resin composite

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Most resin systems are based on:

A

high molecular weight hydrophobic monomers (UDMA, Bis-GMA)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

The only true chemical bonding occurs with:

A

glass ionomers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is the base for self-etching adhesives?

A

phosphate based acidic primers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

How many steps are etch-and-rinse systems applied in?

A

either 3 or 2 (2: conditioner, then primer + adhesive, i.e. optibond solo plus)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

How many steps are self-etching systems applied in?

A

either 2 or 1 (2: etch + primer no rinse, then adhesive), (1: all 3 in one bottle, shelf life and sensitivity make it undesirable)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

How many steps are glass ionomer systems applied in?

A

2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is the smear layer?

A

mineralization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What are you left with when you remove the smear layer?

A

demineralized dentin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What are you bringing into the interface when you add the primer and adhesive?

A

monomers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What does the final hybrid layer consist of?

A

Collagen + adhesive monomers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

Fxn of etching:

A

to achieve adhesion to the restorative resin (i.e. acids, lasers, air abrasion), remove smear layer and open dentinal tubules, increase surface area of the enamel and create micro-porosities

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

With what systems is etching required?

A

All

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

ideal etch enamel:

A

phosphoric aced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

How long to leave etchant on tooth:

A

15-20 sec depending on the acid pH and the substrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

Who was the first to talk about etchant?

A

Buonocore

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

T or F? Phosphoric acid is an organic acid.

A

F. inorganic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

2 types of inorganic acid etches:

A

nitric acid, phosphoric acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

2 types of organic acid etches:

A

citric acid, malice acid (10% for either)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

Acid-etch technique is aka:

A

hypertonic acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

How do different acids differ in terms of how they etch?

A

Leave different pattern in the tooth structure (circular holes for 37% phosphoric acid)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

Effect of acid etch procedure depend on:

A

type of acid, conc (32-37), pH, (0.8-1.2%), etching time (10 vs 20s), form of etchant (gel vs. aqueous delivery system), rinse time (slightly longer than instructions, past when blue is gone), method of application, whether the enamel is instrumented prior, chemical composition and condition of enamel

54
Q

active application:

A

rubbing with microbrush

55
Q

Why is rubbing with a micro brush required with gel etchants?

A

to achieve better etching patterns

56
Q

Different methods of application of etchant:

A

rubbing, agitation, and/or repeated application of fresh acid

57
Q

Examples of how the condition of enamel can vary:

A

primary or permanent teeth, prism-strucuture or prismless, fluoridated, demineralized

58
Q

Enamel etching

A

remove orgainic matieral, inc s.a, high bond stength, predictable bonding, about 20 MPa

59
Q

Dentin etching

A

remove smear later, open tubules, remove mineral, inc s.a., create loose collagen network (5-10 microns in depth), variable substrate, less predictable bonding

60
Q

Why is it important not to leave etchant longer than 15 sec on dentin?

A

leads to greater depth of demineralization, worse adhesion, we want 5-10 microns in depth

61
Q

Prevent application technique for etchant depends upon:

A

type of dentin, i.e. superficial vs. deep dentin, young vs. old (more tertiary and reparative dentin)

62
Q

high bond strength

A

20 MPa+

63
Q

T or F. In todays adhesive systems the bonding to dentin is less predictable than to enamel.

A

F. Not if you follow instructions

64
Q

Appearance of etched enamel:

A

chalky (not true for dentin)

65
Q

Deep vs superficial dentin:

A

Deep: large tubules, closer spaced, more peritubular dentin (66%) than interlobular (12%), lower bond strength

66
Q

T or F? Peritubular is less ideal for bonding than intertubular dentin.

A

T

67
Q

Superficial dentin:

A

small tubules, (0.8um at DEJ), space further apart, PD (3%)/ ID (96%), higher bond strength

68
Q

Which is more ideal for bonding, peritubular or interlobular dentin?

A

intertubular

69
Q

T or F? Primers are required in both dentin and enamel.

A

F. Dentin only

70
Q

Fxn of primer:

A

adhesion promoter, increases surface tension of the collagen

71
Q

Is adhesive resin hydrophobic or hydrophilic?

A

hydrophobic

72
Q

What would happen if we accidentally used primer on enamel?

A

Nothing

73
Q

What type of monomers does primer contain?

A

bifunctional monomer (HEMA) dissolve in solvents (acetone, ethanol, and/or water)

74
Q

What solvents are primers dissolved in?

A

acetone, ethanol, and/or water

75
Q

Are the solvents of primers volatile?

A

Yes

76
Q

From where does the primer displace water?

A

the dentin surface and the moist collagen network

77
Q

How does water displacement aid in adhesion?

A

promotes infiltration of monomers through the nano spaces of the exposed collagen network.

78
Q

What does wetting the surface do?

A

increases the surface tension

79
Q

What are bifunctional monomers:

A

HEMA dissolved in solvents

80
Q

Is the adhesive filler or unfilled resin?

A

either

81
Q

RBC aka:

A

resin composites

82
Q

T or F? most adhesives are filled.

A

F. unfilled. those that are filled have very little

83
Q

T or F? Bonding is chemical.

A

F. micromechanical

84
Q

Fxn of adhesive resin;

A

stabilize hybrid layer and forms resin tags

85
Q

What are formed when resin monomers penetrate micro-porosities created by etching?

A

tag-like resin extensions

86
Q

How are the tag-like extension connected?

A

micro-mechanically interlocked with partially demineralized enamel (entangled w the enamel)

87
Q

hydrophobic, more viscous adhesive resins:

A

Bis-GMA, UDMA

88
Q

higher hydrophilicity, less viscosity adhesive resins:

A

TEG-DMA, HEMA (as a wetting agent)

89
Q

2 types of monomer used to make adhesive resins:

A

hydrophobic and higher hydrophilicity monomers

90
Q

What happens to the collagen fibers when they are dried?

A

they collapse

91
Q

Why do the collagen fibers collapse when they are dried?

A

bc it is supported b inorganic material, demineralization causes the collapse

92
Q

What type fo bonding in requried for adhesion to dentin?

A

wet bonding

93
Q

Fxn of wetting:

A

to get the collagen fibers to raise again

94
Q

Composition of demineralized dentin:

A

70% resin, 30% collagen

95
Q

What forms the hybrid layer?

A

the infiltration of the demineralized dentin layer by resin monomer

96
Q

Composition of dentin before etching:

A

50% inorganic mineral, 30% organic, 20% water

97
Q

T or F. The mineral and water are pretty much gone after etching.

A

T

98
Q

Layers of the hybrid layer:

A

composite resin, adhesive resin, dentin

99
Q

What is the hybrid zone made of?

A

adhesive resin and collagen fibrils, and partially demineralized dentin

100
Q

Resin tags are aka:

A

microtags (lateral branches) or macrotags (larger ones)

101
Q

Fxn of acid:

A

remove inorganic phase and expose rods and collagen

102
Q

What promotes the effective link bw hydrophilic substrate and hydrophobic resin?

A

bi-functional monomers

103
Q

What raises collapsed dentin?

A

primer

104
Q

What is responsible for wetting the collagen?

A

primers

105
Q

The solvents in the primer acts as:

A

water chaser

106
Q

Which is more hydrophilic, dentin or enamel?

A

dentin

107
Q

Fxn of resin:

A

penetrates collagen matrix, interlocks collagen, forms hybrid layer

108
Q

T or F? Etchant can be used on both enamel and dentin.

A

T

109
Q

How far past the margins do we apply the etchant?

A

1mm beyond

110
Q

Why do we apply etchant 1mm beyond the margins of the prep?

A

bc there is a bevel

111
Q

Excess etching leads to:

A

further decalcification/ demineralization, area at bottom of hybrid layer that is weak, decreasing longevity of restoration

112
Q

T or F? The over-etching of enamel would be critical.

A

F

113
Q

After etching the surface should appear:

A

damp

114
Q

Challenge when bonding:

A

working with 2 different tissues, enamel must be dry, dentin must be slightly damp

115
Q

How to dampen detntin if we dried to much:

A

damp microbrush

116
Q

T or F? Primer requires only 1 coat.

A

F. Multiple

117
Q

The suface should appear ___ after solvent evaporation.

A

shiny

118
Q

Goal of air-drying primer vs adhesive

A

evaporate solvent vs. thin, even layer

119
Q

What are we doing if we over dry at the solvent evaporation stage:

A

collapsing the collagen mesh

120
Q

When does the adhesive work best?

A

in thin, even layers

121
Q

Which step do we go back to if contamination occurs at any step?

A

etching

122
Q

What type of adhesive system do we use?

A

2 step etch and rinse system, ethanol solvent, 15% filled (adhesive a little more viscous) with 0=.4 icon barium glass filler (reinforces hybrid zone and penetrates dentin tubule), can be bottle or unidose

123
Q

What do the 2 steps of Optioned Solo Plus consist of

A

etching + primer/adhesive

124
Q

Ethanol based systems work best in:

A

fewer coatings

125
Q

Acetone based systems work best in:

A

multiple layers

126
Q

When should we use the less preferred, indirect vision?

A

when direct vision would result in improper operator positioning

127
Q

The center of focus on the hand mirror should be:

A

the bur contacting the tooth

128
Q

What should you do before using indirect vision?

A

check orientation of handpiece and bur relative to tooth with direct vision.

129
Q

With which visual field should you be monitoring the positioning of the handpiece during the prep?

A

both central and peripheral

130
Q

Pt of origin of Class III caries:

A

interproximal enamel, generally gingival to the contact pt

131
Q

Acid etch allows for:

A

Selective demineralization of enamel

Direct Restoration (23 decks)

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