Resin Composites 1

Question 1

What are Silicates

Answer 1

earliest tooth coloured restorative material

Question 2

what si the reaction to get a silicate

Answer 2

acid base reaction (=salt and water) between

aluminosilicate glass and phosphoric acid

Question 3

what are some properties of silicate

Answer 3

releases fluoride
moisture resist
erosion prone
brittle

Question 4

what do acrylics come as

Answer 4

powder:liquid

Question 5

what is the setting reaction for acrylics

Answer 5

free radical addition polymerisation chemical set so working time limited

Question 6

what is the power used to make acrylics

Answer 6

Pmma beads
chemical initiator
pigment

Question 7

what si the liquid used in acrylics

Answer 7

Mma monomer 
chemical activator (tertiary amine)

Question 8

What are the steps assc with the free radical addition polymerisation recation

Answer 8

activation
initiation
propagation
termination

Question 9

how does termination of free radical addition polymerisation come about

Answer 9

attatch to impurity/free radical or further growing chain

Question 10

what happens to the material when polymerisation takes place

Answer 10

contracts

exothermic

Question 11

what happens when tertiary mania not all used up

Answer 11

poor colour stability (clear-brown)

Question 12

what are acrylics like compared to silicate

Answer 12

less prone to erosion
less soluble
less brittle
less acidic 
lower thermal diffusely

Question 13

how can acrylics irritate the pulp

Answer 13

due to residual Mma

interaction with eugenol

Question 14

what was introduced to acrylics to reduce the shrinkage

Answer 14

inert filler particles to reduce shrinkage

Question 15

what does a basic composite contain

Answer 15

BIS GMA matrix
coupling agent
filler particles

Question 16

what is a resin composite

Answer 16

combination of two comically different materials have props together couldn’t alone

Question 17

what si the modern way of curing

Answer 17

light cuming for command curing

Question 18

what is the BIS GMA matrix

Answer 18

methacrylate based

comonomer such as TEGMA

Question 19

what does th matrix do

Answer 19

controls the viscosity (TEGMA)

inhibitors

Question 20

what is the viscosity of the matrix polymer do

Answer 20

reduces mobility of unreacted monomers

Question 21

unreacted monomers means what

Answer 21

chair side repair

C=C takes part in free radical addition poly

Question 22

in new products siloranes what happens in setting

Answer 22

ring opening

= initial expansion overall contraction

Question 23

what are some examples of siloranes

Answer 23

siloxanes - hydrophobic

oxiranes - ring open poly

Question 24

what are some points about cationic curing used for silorane

Answer 24

camphorquinone 
iodimum salt
electron donor
ring open poly 
less shrinkage

Question 25

what is camphorwuinone

Answer 25

photosensitised

Question 26

what does the electron donor do in cationic curing

Answer 26

decomposes iodiumum salt to an acidic cation

Question 27

what are some fillers

Answer 27

quartz silica glasses ( aluminosilicates, boro silicate, barium oxide)

Question 28

what is a common coupling agent

Answer 28

(delta- meathacryloxypropyltimethoxysilane)

Question 29

what is the properties of coupling agent

Answer 29

difunctional methacrylate characteristics silane interacts and bonds with glass good wetting

Question 30

what are the means of chemical activation for rein comps

Answer 30

chemical - powder liquid - paste liquid - encapsulated

Question 31

what is the means of light curing for resin comps

Answer 31

UV not any more camphorquinone - protects eyes

Question 32

what does camphorquinone do

Answer 32

yields necessary free radicals for poly | visible in blu light

Question 33

what does the coupling agent do

Answer 33

tranfers stresses generated under loading form rigid and brittle filler to more flexible and ductile polymer matrix

Question 34

filler may be added as a

Answer 34

shock abs

Question 35

what are types of resin composites

Answer 35

microfilmed conventional hybrid nancomposites

Question 36

what are some handling characteristics

Answer 36

packable - v viscous flowable - more fluid less filler

Question 37

what is a type 1 restoration

Answer 37

restroe cavs involving occlusal surfaces

Question 38

what is a type2 restoration

Answer 38

restore cav medial/distal ad occlusal surface

Question 39

what is triboloy

Answer 39

changes with function and loss of resin rich outer layer

Question 40

what sit he thermal property proportional to

Answer 40

to filler content | as filler inc coif of thermal expansion dec

Question 41

what is mechanical dept on

Answer 41

filler content type and type efficiency of coupling degree of porosity

Question 42

does cav shape influence overall success of restoration

Answer 42

yes | c = no. bonded surfaces/ no. unbounded surfaces