Resin Composites 1

Question 1

what is a silicates

Answer 1

earliest form tooth coloured restorative

Question 2

what makes a silicate

Answer 2

product of acid base reaction = salt + water between
aluminosilicate glas
phosphoric acid

Question 3

what does silicate release

Answer 3

fluoride

Question 4

what are some features of silicate

Answer 4

moisture sensitive
erosion prone
brittle

Question 5

what are acrylics used fro

Answer 5

make dentures

Question 6

what are acrylics dept on

Answer 6

P:L mixing raio crucial

Question 7

what does chemical setting mean

Answer 7

woking time is limited

Question 8

what si the powder used to make acrylics

Answer 8

Pmma beads no greater than 50 Um

• chemical initiator
• peroxide
• pigment

Question 9

what si the liquid used in making acrylics

Answer 9

Mme monomer
chem activator
tertiary amine

Question 10

what is he setting reaction

Answer 10

free radical addition polymerisation

Question 11

what can cause a yellow tinge after time in acrylics

Answer 11

leftover tertiary amine in system

Question 12

how does the size of the Pmma beads in acrylic affect reaction

Answer 12

tiny beads - accelerate reaction
large - retard set
size affects how light scatters off material

Question 13

what are the sub parts of the free radial addition polymerisation

Answer 13

activation
initiation
propagation
termination

Question 14

what si the activation

Answer 14

benzoyl peroxide cleaved by heat to sp temp

add tertiary amine

Question 15

what is the initiation

Answer 15

when in contact with active species will link up form this

free bonds wan to grow and link similar mols

Question 16

what is the propagation

Answer 16

ends of chain ahem free ends continue to add

Question 17

what is termination

Answer 17

when chain attaches to impurity/ free radical or father growing chinas

Question 18

what happens to the material with polyemridataion

Answer 18

material contracts

- may = gaps

Question 19

is the poly exo or endothermic

Answer 19

exothermic

Question 20

what re acrylics like compared to silicates

Answer 20

less

• prone to erosion
• soluble
• acidic
• brittle

Question 21

what do acrylics exhibit

Answer 21

lower thermal diffusity

- can tolerate hot or cold pulpal sensitivity

Question 22

what does eugenol do in contact with acrylics

Answer 22

impairs polymeirsation

Question 23

what are inert fills used to do

Answer 23

reduce shrinkage

weaken material

Question 24

what are the components of composite

Answer 24

BIS GMA resin matrix
coupling agent
filler particles

Question 25

what is the definition of a resin composite

Answer 25

comb of 2 chem diff materials with distinct interfaces sep components and have properties count be achieved by any component acting alone

Question 26

resin composiites aka

Answer 26

rained acrylics free radical addition polymerisation

Question 27

what are the early products mixd together for composite

Answer 27

limited working time | incur porosity

Question 28

what means command cuing

Answer 28

later light curing technology

Question 29

whats the resin matrix of composite based upon

Answer 29

methacrylate | BIS GMA

Question 30

what are the comonomer is resin matrix

Answer 30

TEGMA control visc - filter addition inhibitors

Question 31

what does the viscosity of the matrix polymer do

Answer 31

reduces mobility of uneducated monomers C=C free radial poly ring opens occur

Question 32

composite says for chair side repair how?

Answer 32

rough surface expo unset monomers and bond new monomers to

Question 33

what are siloxanes

Answer 33

group hug one circle pulls others siloxanes - hydrophobicity oxiranes (ring open poly)

Question 34

what is cationic cure

Answer 34

iodimum salt electron donor ring open poly less shrinkage

Question 35

what re some common fillers for composites

Answer 35

quartz silica glasses

Question 36

what are some glasses use for fillers

Answer 36

aluminosilicates boro silicate barium oxide

Question 37

what is the coupling agent used in resin composites

Answer 37

gamma - methacryloxypropyltrimethoxysilane

Question 38

what is imp about coupling agent

Answer 38

difunctional methacrylate chacteristsics silane interacts and bods with glass good wetting

Question 39

what sit he chemical activation used in resin composites

Answer 39

powder liwuid paste liquid encapsulated - capsules rupture = contact with eachother

Question 40

what si the light activation of resin composites

Answer 40

early ones UV - health risk now CAMPHORQUINONE - - protect eyes - set under operating light to extent

Question 41

what doe camphorquinone do

Answer 41

- have free radicals to start polymerisation - excited @ wavelength 460/80nm - visible blue light - ben by quartz halogen lights

Question 42

what happen to resin when poly

Answer 42

shrinks

Question 43

what can be added resin to prevent as much shrinkage

Answer 43

methacrylate | oxirane - expand open ring reaction

Question 44

what is needed with res and filler to work

Answer 44

coupling agent

Question 45

what is filler also regarded as

Answer 45

shock abs

Question 46

what are the methods of activation

Answer 46

chemical r light

Question 47

what are the types of resin composites

Answer 47

conventional microfilmed hybrid nano composites

Question 48

what are some handling characteristics of resins

Answer 48

packable - viscous | flowable - more fluid/less filler

Question 49

what si type 1 resin composite

Answer 49

restore of cavities involving occlusal surfaces

Question 50

what is type 2 resin composite

Answer 50

all other polymer based filling and restorative materials

Question 51

what are properties considered fr resin composites

Answer 51

- Biocompatible - visc increases when leave tube - exothermic set - setting contraction - thermal diffusely

Question 52

what can increase working time

Answer 52

if light activated | incremental cure

Question 53

what physical properties consider more

Answer 53

tensile and flexural more imp than compressive

Question 54

what is tribology

Answer 54

changes with function and loss of resin rich over layer

Question 55

when considering thermal property what else is to be considered

Answer 55

thermal proportional to filler | mechanical

Question 56

does cavity shape influence overall success of restiration

Answer 56

yes | C factor = NO.bonded surfaces/NO. unbonded surfaces