Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BDS2.5 Dental Materials - operative dentistry > Resin Based Composite Materials - basic system > Flashcards

Resin Based Composite Materials - basic system Flashcards

1
Q

What is resin composite material?

A

materials made of 2 or more constituent materials with significantly different physical or chemical properties that, when combined, produce a material with characteristics different from the individual components

tooth coloured restoration

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

What is resin based composite composed of? (learn)

A

chemically active resin and inorganic filler bound together by a saline coupling agent

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

What are the principal monomers in resin?

A

based on a chemical reaction of 2 resins: bisphenol A and glycidyl methacrylate

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

What does bisphenol A and glycidyl methacrylate form?

A

bis-GMA

‘bowens resin’- the base of a lot of resin composites

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

Can you mix and match materials from different manufacturers?

A

no, create a substandard restoration

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

What is the problem with bis-GMA?

A

HIGHLY VISCOUS, CANNOT BE MANIPULATED CLINICALLY

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

What do you call the monomers you add to bis-GMA to make it less viscous? (handles clinically)

A

diluent monomers / viscosity controllers

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

What are examples of diluent monomers? (4)

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

What happens to dimethacrylate when cured?

A

shrinks

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

What is the effect of a log backbone on dimethacrylate?

A

longer backbone, the smaller the shrinkage as the reaction only occurs at the active methacrylate groups

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

What are the active groups at the end of dimethacrylate?

A

active methacrylate groups at either end of the backbone

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

If resin is used alone, what does the material exhibit? (shortcomings)

A

high shrinkage

inadequate wear

increased exothermic reaction

poor mechanical properties

inadequate optical properties

no radiopacity

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

What is incorporated into the rein to compensate for its short comings?

A

inorganic filler

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

What are the benefits of adding filler to the resin component?

A

increased strength

increased wear resistance

reduced polymerisation shrinkage

improved optical properties such as colour, fluorescence and translucency

less heat production during polymerisation (filler acts as a heat sink)

reduced thermal expansion (closer to tooth)

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

What metal is added to convey radiopacity?

A

barium salts

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

What properties does resin composite take on?

A

properties of the main constituent - filler

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

What are the disadvantages top the filler component being added to resin composite?

A

mechanically become more brittle - due to glass or ceramic

decreased capacity to withstand flexion during function as its modules of elasticity is increased

16
Q

How can resin composiotyes be classified?

A

filler type

size of filler particles

mode of cure

type of resin

presentation

17
Q

What are the 2 filler types?

A

glass or ceramic

18
Q

Describe the glass filler?

A

amorphous (non-crystalline) solid material

19
Q

What are types of glass filler?

A

quartz

silicate

barium, strontium and lithium

strontium-containing glasses

20
Q

What are the features of quartz glass filler?

A

hardest but not radiopaque

21
Q

What are the features of silicate glasses?

A

contain barium but are slightly softer and degrade very slowly when exposed to water

22
Q

What are he features of barium, strontium and lithium containing glasses?

A

they are easier to finish and exhibit an improved surface finish

23
Q

What type of glass filler degrades the fastest in water?

A

strontium-containing glasses

therefore a small percentage of the overall content used

24
Q

How much more dense is the glass compared to resin?

A

glass is about 4 times that of the resin

25
Q

Describe ceramic fillers?

A

inorganic, non-metallic solid prepared by the action of heat and subsequent cooling

26
Q

What synthetic material do ceramic fillers contain?

A

zirconia-silica filler

  • round edges, good translucency and more filler can be incorporated

zirconium oxide (zirconia)

27
Q

What type of composite is used?

A

nanohybrid composite

28
Q

Under ideal conditions, how can packing be substantially improved?

A

resin acting as a binder

29
Q

What is the ideal distribution of packing to achieve an optimum filler loading is called what?

A

trimodal distribution

30
Q

What is a hybrid composite?

A

lots of micro and macro filler molecules, so they fill all the spaces, reduce the amount of resin in there

31
Q

What are nanofilled composites?

A

nanomers are discrete non-agglomerated and non-aggregated particles of between 20-70 nanometers

32
Q

What are the benefits of nanofilled hybrids?

A

act as a single unit enabling high filler loading and high strength

strength of hybrid material but are easier to polish as the individual filler particles are much smaller

33
Q

What are nanofilled hybrids?

A

conventional hybrid materials with nanoparticles added to fill inter-particular space - nanohybrids

most of the products are nanohybrids

34
Q

What is the relationship between resin and filler?

A

put as much filler in as possible but still have sufficient resin to bind the filler together and hold it all together to minimise weaknesses

35
Q

Does bonding occur between resin and filler?

A

no

36
Q

What is needed to bond resin and filler?

A

silane coupler

37
Q

What is the specific name of the silane coupler?

A

y-MPTS

38
Q

How does silane coupler work?

A

bi functional

hydrophilic groups react with the inorganic filler

hydrophobic groups react with the organic resin

39
Q

Where do crack initiation sites occur?

A

interface between the resin and filler

40
Q

Where do fatigue fractures occur?

A

occur as the resin does not have a high resistance to crack propagation

BDS2.5 Dental Materials - operative dentistry (22 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions