Final - Enamel And Dentin Bonding

Front 1

What are the 4 different mechanisms of adhesion?

Back 1

Mechanical, adsorption, diffusion and electrostatic

Front 2

What type of adhesion has interlocking of the adhesive with irregularities in the surface of the substrate, or adherend

Back 2

mechanical

Front 3

What type of adhesion has chemical bonding between the adhesive and the adherend.

Back 3

adsorption

Front 4

What type of adhesion has interlocking between mobile molecules

Back 4

diffusion

Front 5

What type of adhesion has electrical double layer at the interface of a metal with a polymer that is part of the total bonding mechanism.

Back 5

Electrostatic

Front 6

What type of adhesion uses ionic, vanderwaals, covalent or hydrogen bodning?

Back 6

adsorption

Front 7

what adhesion has precipitation of substances onto tooth surfaces that resins can bond to? (uses this mechanism

Back 7

diffusion

Front 8

what adhesion uses this mechanism? penetration of resin into tooth that forms tags

Back 8

mechanical

Front 9

what adhesion uses this mechanism?
chemical bonding to the inorganic component (HA -hydroxyapatite) or organic components - (mainly type I collagen) of tooth structure

Back 9

adsorption

Front 10

T/F a combination of the previous mechanism is possible

Back 10

true

Front 11

T/F ALMOST every case of dental adhesion is based primarily on mechanical bonding.

Back 11

true, chemical bonding may occur as well, but generally makes a limited contribution

Front 12

What are the requirements for adhesion?

Back 12

good wetting, clean surfaces

Front 13

many parts are ________ one part are _____-

Back 13

polymer,monomer

Front 14

monomers are in what phase?

Back 14

liquid

Front 15

What are the reactions of radical polymerization?

Back 15

initiation, activation, propagation, termination

Front 16

These kind of reaction usually occur with unsaturated molecules containing double bonds (usually difunctional, MMA (methly methacrylate) is monofunctional)

Back 16

free-radical polymerization

Front 17

are there any by-products after polymerizatin?

Back 17

no

Front 18

________ monomers, widely used in dentistry, undergo chain reaction polymerization.

Back 18

acrylic

Front 19

What is an accelerator to increases the rate of activation?

Back 19

chemical, light, heat

Front 20

_______ or _________ can consume newly formed free radical and prevent or postpone initiation.

Back 20

inhibitors or retarders

Front 21

in the termination phase, is there more than one possibe event?

Back 21

yes,
propagation continues, until all monomers were used up if it were not for the strong endency of radical to react in pairs
this tendency is overcome by the use of small amount of initiators (radical species) and large amounts of monomer.

Front 22

When you create a structure with 2 double bond = rigid cross-linked structure, give an example of this with what we use.

Back 22

dimethylacrylate

Front 23

When the structure has 1 dble bond and creates linear chains (_______) then it is a monomethylacrylate.

Back 23

plastic

Front 24

Name so advantages of pure polymers:

Back 24

Can control viscosity
Easily wet surfaces
Adhesives are solvent diluted monomer

Front 25

During activation the ______ bonds are broken and can then be added to.

Back 25

double

Front 26

During the propagation phase does the volume ________ (inc.dec.)

Back 26

decreases, making linear polymers. with monomethylacrylate

Front 27

POlymers use ______- bonds. They have a ________ molecular weight. and long molecules are usually composed of non- ______ elements. (usually CONH - organic)

Back 27

covalent, high, metallic

Front 28

What is a disadvantage to using polymers?

Back 28

shrinkage, (the more volume, the greater shrinkage) - pure resins sed primarily in thin films.
poor wear resistance: inorganic fillers added to improve wear and reduce shrinkage (composites)

Front 29

What can you add to decrease the disadvantages of polymers

Back 29

add inorganic fillers = composites

Front 30

To make the composite you mix (thick) _______ with (watery) ______ to fll all grooves (becuase you can't fill spaces with honey!)

Back 30

monomer, polymer

Front 31

What are the two phases of dental composites

Back 31

matrix phase
dispersed phase

Front 32

________-- ________ is the (continuous phase). has monomer resin, photoinitiars, and pigments

Back 32

matrix phase

Front 33

_____ ______ is the discontinuous phase. has glass fillers and silane coating

Back 33

dispersed phase

Front 34

_______-- resin is when you have a mixutre of two or more materials.

Back 34

composite

Front 35

T/F The goal of composite resin is to blend properties of the parts to obtain intermediate properties and take advantage of the best properties of each phase.

Back 35

t

Front 36

A dental composite is a ______- (filler phase) mixed into a _______-- (matrix phase).

Back 36

dispered matrix

Front 37

What are the methods of polymerizing composites?

Back 37

self curing, ultraviolet light curing, visible light-curing, dual curing, staged curing, can't fill to level of enamel with our materials

Front 38

When something is harder/strong has more ______- content.

Back 38

mineral

Front 39

T/F silicate glasses, strengthen and have optical properties

Back 39

true

Front 40

What makes the initial mixture of dental composite fluid and moldable

Back 40

acrylic monomers

Front 41

The composite resin is supplied as a past (whether it is thick or thin depends on ________)

Back 41

filler content

Front 42

Usually ___- the matrix of any system produces more desirable clinical properties.

Back 42

decreasing

Front 43

what is the phase that generally is transiently fluid during manipulation or placement of teh material; tend to have the least desirable properties; usually decreasing teh matrix of any system produced more desirable clinical properties

Back 43

continuous phase

Front 44

It is important for the _____ phase to be bonded effectively to the _______ phase to distribut ________ within the system to all phases.

Back 44

disperesed, continuous, energy

Front 45

How do you classify the composite resin?

Back 45

by the size of the filler

Front 46

Why type has a (mix) with colloidal microfils and paste like stuff?

Back 46

Hybrid type - has colloidal microfill and silicates

Front 47

What is the purpose of having colloidal microfills?

Back 47

helps to keep fills suspended

Front 48

What filler size corresponds to these?
10-100 microm
1-10 microm
.1-1mcicrom
.01 - .1 microm

Back 48

macrofill
midifill
minifill
microfill
nanofillers are the smallest - these are all nanofillers

Front 49

fillers bond to ______ phase

Back 49

resin

Front 50

what elements are found in silicate glasses:

Back 50

barium zinc and yttrium -modified silicate glasses currently most popular fillers

Front 51

what is the most popular filler used today?

Back 51

modified silicate glasses

Front 52

in modern composites silica particles are _________ with monomolecular filsm of _________ coupling agetns

Back 52

precoated, silan

Front 53

there are many various sizes, but the bigger the filler the ______ the surface

Back 53

rougher

Front 54

______ _______ ______ are difunctional molecules that couples or bonds fillers to polymer; provies interfacial bonding between the phase

Back 54

silane coupling agents

Front 55

when do silane coupling agents work best?

Back 55

with silica particles, thus all composites have been based on silica -containing fillers

Front 56

What elements are added to produce radiopaque qualties of the filling? in non-crystalline filler

Back 56

Ba, Zn, B, Zr, Y ions used to produce radiopacity in filler particles - makes radiodiagnose easer on x-ray.

Front 57

non-crystalline (glasses) has been modified. What element are added to make the filling softer?

Back 57

Na, K, and CA

Front 58

non-crystalline (glasses ) have been modified. What elements are added to make the filler more crushable?

Back 58

Al, Li

Front 59

Crystalline is radioluscent, why?

Back 59

quartz, crystobalit, trydymite - radioluscent, very hard and abrasive - don't have elements that no -crystaline have.

Front 60

Is the filler surface hydrophobic or philic?

Back 60

philic

Front 61

What is the bifunctional molecule that bonds to the filler surface and changes it from a philic to a phobic and assist in bonding the filler to the polymer.

Back 61

silane

Front 62

Composite monomers are hydro____

Back 62

phobic

Front 63

Bis-GMA has high viscosity
UDMA - moderate viscosity
TEGDMA - low viscosity
These are all examples of what?

Back 63

composite MONOMER

Front 64

What material do we use when we make custom tray?

Back 64

dimethylacrylate

Front 65

Bis-GMA and UDMA have a ______ mol. weight

Back 65

higher

Front 66

TEGDMA ________ like h20

Back 66

runs

Front 67

the Bis-GMA and UDMA recude shrinkage, but what is the disadvantage?

Back 67

difficult to mix filler in with

Front 68

the glass surface is hydro_ and the monomers are hydro ____--

Back 68

philic,phobic - thus they have poor wetting and no bonding - so USE SILANE!

Front 69

something unique of composite monomers is that they have ____- functional gropus on each side and can make cross-linked structure = more riged

Back 69

2

Front 70

T/F bis-GMA is an oligomer

Back 70

true

Front 71

What are examples of resin matrix?

Back 71

bisGMA, UDMA, TEGDMA

Front 72

Oligomers are known to be ____.

Back 72

thick

Front 73

t/F udma is an oligomer?

Back 73

true

Front 74

t/f TEGDMA is an oligomer?

Back 74

false, it is a DILUTENT

Front 75

how does TEGDMA improve degree of polymerization

Back 75

more dble bonds convert, better physical and mechanical properties.

Front 76

What do most composites empoy as a photoinitiator?

Back 76

camphorquinone - yellow in color absorbs blue light

Front 77

What are the three levels of dentinal reaction to caries?

Back 77

reaction to long term, low-level acid demineralization associated with slowly advancing lesion
reaction to a moderate -intensity attack
reaction to sever, rapidly advancing caries characterized by vary high acid levels

Front 78

What determines the material structure?

Back 78

atomic arragnetment: crystallin vs. non crystallin
bonding: primary (metallic, ion, covalent), secondary (hydrogen, van der waals)
composition: elements and phases)
Defects: macroscopic (pores) atomic scale (microflaws)

Front 79

What are the materials properties?

Back 79

physical: environment
chemical: bonding affeted
biologic: living tissue
Mechanical: forces

Front 80

In 1955 what was an introduction of acid-etch technique?

Back 80

buonocore

Front 81

what percentage of phosphoric acid did buonocore use?

Back 81

85

Front 82

What is the first step in enamel bonding?

Back 82

etching dissolves some mineral (like caries)

Front 83

what leave a very irregular enamel surface (whitish looking like incipient caries)

Back 83

etching

Front 84

When a low viscosity monomer (fluid resin-based material - TEGDMA) where does it go?

Back 84

the resin flows into microporosities (added by capillary action)

Front 85

monomers in the material polymerize and become ________ with enamel

Back 85

interlocked

Front 86

formation of ______- within the enamel surface is the fundamental mechanismof adhesion of resin to enamel

Back 86

microtags

Front 87

what are the two types of resin tags

Back 87

macrotags, and microtags

Front 88

_ is a resin tage which forms between enamel and rod peripheries

Back 88

macrotags

Front 89

_ is a smaller tag that forms from resin penetrating dissolved crystals

Back 89

microtages

Front 90

t/f the chemical composition of enamel varies

Back 90

t, if the surface has been removed, fluorinated, demineralized and remineralized are all of different composistion

Front 91

what kind of acid is used for etching?

Back 91

phosphoric

Front 92

what is the concentration of the acid we currently use?

Back 92

most current phosphoric acid gels are 30-40% -

Front 93

concentration too low or too high can result in

Back 93

formation of precipitates, or poorly defined etch patterns respectively

Front 94

What are the main etching variables

Back 94

time (some studies suggest as low as 15 sec.)
etchant form (liquid, gel)
rinse time (20 sec)
chemical composition of enamel

Front 95

what is used for the interprism resin penetration?

Back 95

macrotags

Front 96

etching can increase ______about 2000x

Back 96

surface area

Front 97

ENAMEL ETCHING CAN RESULT IN __ different micromorphologic patterns

Back 97

3

Front 98

Type I etching is mainly through ______ bonding

Back 98

mechanical

Front 99

Properties of a material depend on the direction; for example, wood. In a piece of wood, you can see lines going in one direction; this direction is referred to as "with the grain". The wood is stronger with the grain than "against the grain". Strength is a property of the wood and this property depends on the direction; thus it is ________

Back 99

anisotropic:

Front 100

The stronger bonding occurs where in enamel bonding?

Back 100

rod ends

Front 101

Th weaker bonding occurs where in enamel bonding?

Back 101

to sides of rods because enamel is anisotropic - not bonding to the 'grain' of the wood

Front 102

t/f enamel structure is very consistent regardless off location.

Back 102

true

Front 103

t/f enamel can be dry with no moisture

Back 103

true

Front 104

t/f dentin can be dry with no moisture

Back 104

fAlse

Front 105

how long can sealants last?

Back 105

10-20 years

Front 106

are enamel bonds long lasting and durable?

Back 106

true

Front 107

what is easier to place, and enamel bond or dentin bond

Back 107

ENAMEL

Front 108

do sealants wear away?

Back 108

they tend to slowly wear away until only small amount left in the grooves

Front 109

When dentin bonding do you still etch?

Back 109

yes, the dentin surface was altered from cavity prep,

Front 110

What does etching surface of dentin serve to do?

Back 110

enlarges tubular openings
remove or solubilize smear layer (ideally would leave smear plugs which would greatly reduce dentin permeability and sensitivity)
demineralize surface detin

Front 111

What do you have to be careful of etching dentin in relation to the demineralization of surface dentin

Back 111

removes much of the surface HA; leaves interconnected network of collagen fibrils. too much etch - too much demineralization - weak layer between restoration and tooth

Front 112

what are the problems of dentin bonding?

Back 112

LOTS OF WATER - the enamel adhesives are very hydrophobic - so wouldn't completely penetrate SMEAR LAYER covered surface and was loosely attached (weak link like painting a greasy wall-paint peels off)
DENTINE STRUCTURE DIFFERS with location and age

Front 113

t/f the dentine structure differs with location and age

Back 113

treu

Front 114

how should you dry etched dentin?

Back 114

air dry, don't desiccate
short bursts of air not continuous

Front 115

after etching dentin does it need to be rinsed?

Back 115

yes this removes excess acid gel to stop etch process

Front 116

why should the dentin be left slightly moistened?

Back 116

improves primer and adhesive ability to penetrate collagen fibrils to form hybrid layer, which is basis for micromechanical bond to dentin

Front 117

why must dentin remain moist?

Back 117

to keep collagen from collapsing (like sponge)

Front 118

collapsed dentin (like spaghetti noodles) is ______ permeable to hydrophilic monomers and creates weak interface

Back 118

less

Front 119

can poor drying technique of etched dentin produce pain?

Back 119

YES - seen in posterior teeth

Front 120

After etching and air dry of dentin, what is next and why?

Back 120

apply primer/resin - made of hydrophilic resins (monomers) in a water, alcohol, or acetone carrier -photoinitiators present (yellow color)
continuously applied for 15-20 sec

Front 121

What do the resins placed after etching do for dentin bonding (wet bonding)?

Back 121

penetrate into the inherently moist dentin surface and copolymerize with the composite restoration;

Front 122

what is the hybrid layer, where does it come from

Back 122

some of the bonds form from resin tags extending into tubules; most of bond strength is form resin penetrating and adapting to demineralized intertubular dentin and exposed collagen fibres; reslultant interdiffusion zone often ermed the hybrid layer

Front 123

Why do you lightly blow air over the adhesive (resin/primer) in dentin bonding?

Back 123

thins out the adhesive layer which is inherently weak, drives off volatile carrier used to thin primer/adhesive mix

Front 124

does the primer need to be cured in dentin bonding?

Back 124

yes, 10-20 sec cure of adhesive, surface remains unpolymerized due to oxygen inhibition

Front 125

after the primer has been light cured in dentin bonding, what is next?

Back 125

apply composite resin into restoration
no more than 2 mm increments - light scatters and not enough gets into deeper areas to assure good polymerization

Front 126

what are the 3 major elements or strategies of dentin bonding?

Back 126

smear layer - removed with acid etch similar to enamel etch (shorter time)
hydrophilic (love water) Monomers (primers) used instead of hydrophobic