W1D1 - 533 - Operative Dent - Enamel And Dentin Adhesion

Front 1

Why do we etch the surface?

Back 1

to increase surface area and make microtags within the enamel surface - the fudamental mechanism of resin-enamel adhesion

Front 2

Enamel etching results in 3 different micromorphologic patterns - what are they?

Back 2

Type I: the dissolution of prism cores without dissolution of prism peripheries
Type II: etching pattern the opposite of type I
Type III: lest distinct than the other two patterns, it includes area that resemble the other patterns and area whose topography is not related to enamel prism morphology.

Front 3

What is the percentage of hydroxyapatite in enamel?

Back 3

86% -
2% organic
12% water

Front 4

What is the basic unit of enamel?

Back 4

a cylindrical shaped prism (rod) which has a SPATIAL relationship witheh "interprismatic region'
When viewed together look like a key hole

Front 5

T/F Enamel Adhesion is a penetration and interlock and is conservative

Back 5

true

Front 6

What is the % of phosphoric acid used in etchant systems/

Back 6

30-40% phosphoric acid - time from 15-60 sec.
Lower: precipitaion of dicalcium phophate monohidrated

Higher: poor definition

Front 7

Etched tooth will look:

Back 7

frosty

Front 8

What is the best type of etching? I, II, III?

Back 8

II, it is the best defined
(when prism peripheries are removed and cores remain

Front 9

What is the percentage of hydroxy apatite in dentin?

Back 9

45% - still mostly mineral
30% organic
25% water

Front 10

T/F the dentin tubule diameter INCREASES as you get closer to the pulp

Back 10

true

Front 11

Do you want to remove both the smear layer and smear plug?

Back 11

yes

Front 12

What is the smear layer?

Back 12

a product of bacteria and debris created upon the preparation

Front 13

How do you remove the smear layer?

Back 13

Permeability
Etchant
the smear layer is bad and interferes

Front 14

What content of the dentin is removed when etched?

Back 14

mineral content - only put on for 15-20 seconds. if over will remove too much.

Front 15

AFter you have etched the dentin , then what do you do?

Back 15

Place the adhesive (or primer if you need that first)

Front 16

Is the composite hydrophilic or hydrophobic what about the tooth?

Back 16

Composite: HYDROPHOBIC
TOOTH: Hydrophilic

Front 17

What is the active component of the dentin bonding agents? and what does it do?

Back 17

the primer: methacrylate (hydrophobic)
dentin functional group (hydrophilic)

Front 18

What is found in the dentin bonding agents?

Back 18

primer, solvent (alcohols, acetones, water), may have some hydrophobic resins in the mix

Front 19

HEMA and HPMA are examples of what tyeps of dentin functional groups?

Back 19

hydroxy group - no interaction

Front 20

PENTA, Phenyl-P, Bis-GMA-P,GPDM, MDP are all examples of what?

Back 20

phosphate ester dentin functional groups and have ionic interactions with the Calcium within the dentin

Front 21

What two types of dentin functional groups have ionic interactions?

Back 21

carboxylic acid and phosphate ester

Front 22

What percentage of the bond with the adhesive is ionic and what percentage is mechanical bonding?

Back 22

ionic: 10%
mechanical: 90%
mainly mechanical retention
better to enamel than to dentin (because have better control) - dentin fluid, penetration of resin
Rewet dentin

Front 23

What is the Hybrid Layer?

Back 23

Resin -Dentin interdiffusion zone -
NOT the same as the smear layer - weakest pt.

Front 24

What is C-Factor?

Back 24

Ratio between bonded surfaces vs. non-bonded
Stress and marginal gaps
Enamel margins

Front 25

Considerations when bonding to dentin and enamel at he same time:

Back 25

ratio of dentin surface to enamel surface gets larger
must rely more on DENTIN bonding than enamel

Front 26

What are the Clinical Factors in Adhesion?

Back 26

Variation in mineral content
Class V: more stress there, bonding to enamel and dentin
- lateral forces: bruxism
- Shrinkage
Desensitization: etching and adhesives
Sclerotic Dentin
- high content mineral and occlude to everything - hard to bond to so remove top layer.

Front 27

What is Sclerotic Dentin, where is it found?

Back 27

Peritubular dentin widens - reacive, physiologic (aging)
Calcified material
harder than dentin
seals tubules (protects)
physical/chemical process

Front 28

What did a first generation adhesive bond to?

Back 28

Calcium on surface

Front 29

What did a second generation adhesive bond to?

Back 29

to smear layer - wetting denting, penetration: hydrophobics so didn't attract

Front 30

What did the third generation bond to and who created it?

Back 30

Fusayama et al 1979
Remove semar layer or not; NOT dentin

Front 31

What is 3 step total etch?

Back 31

When you apply the
E + P + B in three separate steps

Front 32

What is One-bottle total etch?

Back 32

when you apply the etchant then use one bottle to apply the p+B at the same time

Front 33

what is two-bottle self-etch

Back 33

when the etchant and primer are within the same bottle, thus no drying is required. much easier to use for dentinal bonding.

Front 34

What is all-in-on self etch?

Back 34

when you only use one bottle that everything - EPB is in.

Front 35

What kind of etching system do we use in the preclinic?

Back 35

optibond solo - one-bottle total etch

Front 36

What are some characteristics of the twosteps self-etch?

Back 36

Acidic Primers (not rinsed)
Decrease in bond strenght in enamel
MIld/Moderat/Aggressive
Includes part of smear plug
Not drying, less sensitive to moist
Good deminearlization/penetration

Front 37

What are some of the characteristics of one step self etch?

Back 37

uncured ionic monomers
semipermeable membrances
hydrophilic -overtime bonding integrated by water
water degradation

Front 38

What characteristics are seen with the 3step total etch?

Back 38

bond to enamel and dentin - bond strength 12-30mPa
Components: ecth, primer(hydrophilic), and solvent (aceton, ethanol, water)
Adhesive: filled/unfilled hydrophobic and hydrophilic

Front 39

pH an INFLITRATION is effected by self-etch, is it better to have a mild or inermediary strong acid or a really strong acid

Back 39

Mild for Self Etch - depending on the pH it will go deeper or closer to surface

Front 40

What factors effect the durability of the adhesive restorartive material?

Back 40

initial situation, Tx procedure, material used, operators' skill, pt.

Front 41

In the composite spectrum, what was created first?

Back 41

composites , GI, RMGI, compomers

Front 42

What is a glass ionoer composed of?

Back 42

polymer matrices (polyacrylic acid)
Glass reinforcing filler particles (aluminosilicated with calcium and fluoride)

Front 43

When speaking of Filler particle size - what are Mega, Macro, Micro, Nano, ad hYbrid fillers composed of?

Back 43

Megafillers: >100um
Macrofiller: 10-100um
Midifillers: 1-10um
Nanofillers: .0005-.01um
Hybrid: range of size
Homogenous: filler and uncured matrix material
Heterogenous: involves procured composite or unusal filler
Modified: if linclued novel filler modification and conventional fillers

Front 44

T/F Almost all important properites are improved by using higher filller levels.

Back 44

true -
yes, as filler level increases, fluidity decreases
highly filled=large particles -rougher surface

Front 45

What elements can be added to produce radiopacity?

Back 45

barium, zirconium, yttrium, boron

Front 46

What elements have been added to produce desirable changes in properties (make glass more easily to crushed)

Back 46

lithium and alumninum

Front 47

Filler particles size has a direct effect on the surface ___- of the ground, finished and polished composite.

Back 47

roughness.
Filler particles are hader than the matrix
During finishing, some particles may be left protruding from the surface, wheras others are stripped out of the surface leaving holes. If the particles are very small then the resulting surface roughness is of litle concern.

Front 48

Effectiveness of restoration finishign and polishing procedures depends on careful use of ?

Back 48

successively finer abrasive material to eliminate larger scratches or defect and replace them with smaller ones.

Front 49

Classsification of Composites generally are classified with respect to the ________, ___- and ________ of theri filler or matrix phases or by their ________- properties.

Back 49

components, amounts, and properties of their filler or matrix phases or by their handling properties. - most common classification method is based on filler conten, filler particle size, andmethod of filler addition.

Front 50

Composites also could be defined on the basis of the matrix composition - give examples of this.

Back 50

BIS-GMA OR UDMA

Front 51

or composites can be classified by the poolymerization method - what types are there?

Back 51

self-curing, UV light-curing, visible light-curing dural-curing, or staged-curing) - this doesn't communicate as much info needed

Front 52

Almost ALL impt. properties of composites are improved by using _ filler levels.

Back 52

HIGHER

Front 53

T/F silica fillers are approx 3x as dense as acrylic monomer (or polymer)

Back 53

true

Front 54

What are the characteristics of flowable composites?

Back 54

low-viscosity materials that possess particle sizes and particles size distributions similar to those of hybrid composites., but with reduced filler content, which allow the increased amt. of resin to decrease the viscosity of he mixture. - used for: pit and fissure sealants or small anteror restorations

Front 55

Materials with higher filler content have been suggested for use in CLass:

Back 55

I, II, III< IV, and V restorations, although better suited for only conservative restorative procedures.

Front 56

Packable composites: also referred to as __ composites were developed in a direct effort to produce a composite with handling characteristics simliar to amalgam - "packable" -

Back 56

condensable - used for primarily class I and II restorations

Front 57

Notes about curing composites?
Microfills are more _______(easy or difficult) to cure
Darker shade are more (E/D) to cure
If thickness is >1.5-2.0mm, light ___(may or maynot) completely cure
What is the most popular polymerization technique used today?

Back 57

Microfills: more difficult to cure
Darker shade: more difficult to cure
May not
Visible light curing

Front 58

Ideally, the clinical manipulation of the curing light should be __ from the composite.

Back 58

tip should be within 2mm of composite

Front 59

Restoration effects of curing light include:
Filler Particles ___ light
Darker colorants _____ light
IDEAL: no more than _______mm increments light-cured at a time.
Problems of light penetration are only slightly ovecome by increasing curing _____.

Back 59

scatter
absorb
1.5-2.00mm
time

Front 60

The composition, structural properties of composites: as the overall filler content increases, the physical, chemical and mechanical properties generally _______.

Back 60

improve

Front 61

Does post-curing help>

Back 61

post cure for 20-60 sec., may improve wear resistance. - has never been proved however

Front 62

acrylic resin monomers used in dentistry undergo polymerization in stages named:

Back 62

activaition, initiation, propagation, and termination

Front 63

What stage does light curing effect?

Back 63

initiation process

Front 64

The higher the C-factor the higher the?What classes have the highest/lowest C-factor?

Back 64

more likelihood of high interfacial stress
Class I: highest
CLass II -> Class III -> Class IV -> Sealant or Class V

Front 65

T/F GI set more slowly and seem to dvelop less interfacial stress.

Back 65

t

Front 66

Flexible restoartions (_____ elastic moduli) would be clinically more retentive b/c of improved accommodation to flexural forces.

Back 66

low

Front 67

If tooth prep is narrow, composites can beused with little concern about _.

Back 67

wear

Front 68

According to research, _________ composites are the most wear-resistant formulation.

Back 68

MICROFILL

Front 69

Where do most secondary caries occur?

Back 69

along proximal or cervical margins where enamel is thin and difficult to access during restoration - incidence of secondary caries acan e as low as 3% after 10 yrs.