Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

BDS2 DMS > Composite > Flashcards

Composite Flashcards

1
Q

name three advantageous properties of composite

A

aesthetic
strong
wear resistant

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

what three phases do composites exist as

A

resin matrix
dispersed inorganic filler particles
silane coupling agents

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

what size of composite filler particles are considered to be fine

A

0.5 -3 micrometres

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

what size of composite filler particles are considered to be microfine

A

0.04 micrometres - 0.2 micrometres

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

what size of composite particles are considered to be nanofilled

A

1-10 micrometres

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

name three clinical uses of composite

A

direct filling material for caries
abrasion/ erosion restoration
trauma

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

what are the five components of composite filling material

A

filler particles
resin
camphorquinone
low weight dimethacrylates
silane coupling agents

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

what is the purpose of camphorquinone

A

it is a photoinitiator

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

what is the function of low weight dimethacrylates in composite

A

allow mechanical properties to be varied

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

what is the function of silane coupling agents in composite

A

allows intimate contact between filler and resin

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

what monomers are used in the resin for composite material

A

Bis-GMA
urethane dimethacrylates

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

what is a key characteristic of a monomer for composite resins

A

has a difunctional molecule
- carbon-carbon double bonds that facilitate crosslinking that generate the growth of the monomer via free radical addition polymerisation

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

what does camphorquinone require to be activated

A

blue light

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

what does camphorquinone produce when activated by blue light

A

radical (electrically changed) molecules which initiate polymerisation of Bis-GMA

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

what are the two changes that occur to composite resin properties after activation of camphorquinone

A

increases molecular weight of resin
increases viscosity and strength

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

what is the action of silane coupling agents in composite

A

prevents moisture that might develop on the glass (filler) surface - which would prevent a good bond

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

where should microfilled or submicron hybrid composites be used

A

anteriorly

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

where should heavily filled composites be used

A

posterior

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

what type of composite resin can be used anywhere in the mouth

A

submicron filled

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

which type of composite material has the highest filler loading capacity which is wanted for a stronger material

A

hybrid composite resin

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

name four effects of adding more filler particles to composite

A

improved mechanical properties
lower thermal expansion
lower polymerisation shrinkage
improved aesthetics

22
Q

how does light-cure composite become activated

A

blue light (430-490 nm) activates camphorquinone which forms free radicals, breaking double bonds which establishes polymerisation reaction

23
Q

how do self cured composites become activated

A

when the 2 pastes are mixed together they produce free radicals, breaking double bonds and allowing polymerisation reaction

24
Q

name three advantages of using a light-cure composite

A

extended working times
less finishing and polishing
higher filler particles

25
why do light cure composites have higher filler composition that self cure composites
self cure composite requires 2 pastes to be mixed and must be low enough viscosity to allow this to happen
26
what is the standard way of testing a composite's depth of cure
cure composite in a cylinder - scrape soft uncured composite from bottom, half the volume of hard composite that remains and this value is considered depth of cure
27
what is the hardness profile of a composite
the depth of cure is the depth at which the hardness is 80% of the top surface
28
which layer of thickness should you use for hybrid composites
2mm increments
29
name three potential problems of light curing composite
premature polymerisation from dental lights optimistic depth of cure values light/ material mismatch leading to overexposure
30
name four factors that depth of cure depends on
product shade duration of light exposure intensity of blue light source
31
name two patient considerations when using light cure composite
it is an exothermic reaction - can be damaging to the pulp if not sufficient hard tissue left diverging blue light beam
32
name two of the main concerns of polymerisation shrinkage
poor bonding to tooth/ microleakage potential for cuspal fracture
33
how does the fracture strength of composite resin compare to enamel
it is better than enamel (350 MPa for composite)
34
what characteristics would a composite being placed in large posterior cavity require
high strength high young's modulus (rigidity) high abrasion resistance
35
what is one advantage and one disadvantage of conventional filler composite
strong problems with finishing due to soft resins and hard particles
36
name one advantage and one disadvantage of microfine filler composites
smooth surface for longer due to smaller particles lower fracture strength and easily abraded
37
what three factors of composite affect its wear resistance
filler particle size distribution resin type effectiveness of coupling agent
38
what is used to etch enamel when preparing the tooth for composite application
37% phosphoric acid for 20 seconds
39
what is the purpose of acid etch technique
removing the top layer of enamel, revealing a notched sub-structure
40
what are the aims of bonding to tooth structure
reduce microleakage counteract polymerisation shrinkage
41
what two characteristics does composite fall short on when compared to enamel and dentine
hardness elastic modulus
42
what is composite's thermal conductivity
low - good as it avoids pulpal damage
43
which materials match enamel and dentine the best for thermal expansion
glass ionomer cements
44
when may composite filling materials be considered not biocompatible
if they are not fully cured which can lead to unpolymerised resin leaking out
45
what does caries left at the ADJ result in
unsupported enamel and early breakdown of the restoration margin
46
what is the smear layer and how is it removed
layer of organic material which is produced whenever a highspeed or slow speed handpiece is used on dentine this is removed by etch
47
when finishing a composite restoration, what is used for gross reduction
diamonds, carbide finishing burs finish disks strips of alumina
48
what is used for final finishing of composite
abrasive impregnated rubber rotary instruments disks rubber cup with polishing paste
49
why is a smooth finish of composite desired
to prevent retention of plaque
50
when might flowable composites be indicated
cervical erosion abfraction
51

BDS2 DMS (2 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions