Brainscape's Knowledge GenomeTM

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


See full index

BDS2 CDS Dental Materials Science > Cavity lining materials > Flashcards

Cavity lining materials Flashcards

ILO 1.6c: have knowledge of the clinical and physical properties as well as the clinical uses of a range of dental materials

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

what materials are placed into cavities?

5

A

composite resin
glass ionomer
amalgam
precious metal
ceramic

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

what are the disadvantages of restoratives?

3

A

may not make immediate contact with the tooth surface - secondary caries
heat released during setting/curing can damage pulp
release of chemicals may irritate pulp

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

what do cavity lining materials do?

2

A

prevent gaps
act as a protective barrier

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

what are the differences between cavity bases and linings?

A

cavity base
* thick mix placed in bulk
* dentine replacement to minimise bulk of material or block out undercuts
cavity lining
* thin coating over exposed dentine
* dentine sealer to promote health of pulp

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

what is the purpose of a cavity liner?

3

A
  • pulpal protection from chemical stimuli, thermal stimuli and bacteria and endotoxins
  • therapeutic to reduce inflammationn within pulp
  • palliative to reduce symptoms prior to definitive treatment
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what are the properties of lining materials?

9

A
  • ease of use
  • thermal properties
  • mechanical properties
  • radiopaque
  • marginal seal
  • solubility
  • cariostatic
  • biocompatible
  • compatible with restorative materials
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how are lining materials easy to use?

3

A

easy to mix
long working time to allow easy placement
short setting time

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

what are the thermal properties of lining materials?

3

A

low thermal conductivity
similar thermal expansion coefficient to dentine
similar or lower thermal diffusity to dentine

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

what are the mechanical properties of lining materials?

2

A

high compressive strength
modulus similar to dentine

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

why should lining materials be radiopaque?

2

A

should be easy to see the difference between lining and tooth
easier to see of there are any leakages or secondary caries

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

why should the lining material be a marginal seal?

A

should form a chemical bond to dentine which is permanent and impermeable

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

how soluble should a lining material be?

A

low solubility

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

how is a lining material cariostatic?

3

A

releases fluoride
antibacterial
prevents secondary caries around restoration

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

how is the lining material biocompatible?

3

A

non-toxic
doesn’t damage pulp (ph neutral, no excess heat when setting)
low thermal conductivity

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

what types of materials can be bases or liners?

4

A

setting calcium hydroxide: liner
zinc oxide based cements: base
glass ionomer and resin modified glass ionomer: base or liner
palliative cements: base

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

what kind of reaction occurs with setting calcium hydroxide and what is the reaction between? what does it result in?

3

A

setting reaction is a chelation reaction
between ZnO (filler material) and butylene glycol disalicylate (reactive element)
results in a cement with an initia pH of around 12

17
Q

how does setting calcium hydroxide work?

2

A
  • kills cariogenic bacteria as creates a highly alkaline environment
  • irritates the odontoblast layer to start making reparative tertiary dentine (calcified bridge forms at base - calcium comes from pulp)
18
Q

what are the properties of setting calcium hydroxide?

5

A

quick setting time ✓
radiopaque ✓
easy to use ✓
low compressive strength ✖
unstable and soluble ✖

soluble=if cavity leaks then lining disappears-may be due to wet dentine

19
Q

what are examples of zinc oxide based cements?

5

A

zinc phosphate
zino polycarboxylate
zinc oxide eugenol (ZOE)
resin modified ZOE
ethoxybenzoic acid (EBA) ZOE

20
Q

what makes up the powder and liquid components of zinc phosphate cement?

A

powder
* zinc oxide
* magnesium dioxide
* alumina and silica oxides
liquid
* phosphoric acid (aq)
* oxides which are buffers - aluminum and zinc oxides

aluminium oxide - even consisteny, zinc oxide - slows reaction

21
Q

what reaction occurs with zinc phosphate cement and what is the end product?

3

A

ZnO + 2H3PO4 -> Zn(H2PO4)2 + H2O (acid base reaction)
ZnO + Zn(H2PO4)2 + H2O -> Zn3(H2PO4)2.4H2O (hydration)
crystalised phosphate matrix produced

22
Q

what are problems with the zinc phosphate cement?

7

A
  • low initial pH around 2 = pulpal irritation
  • exothermic setting reaction (gives off heat)
  • not adhesive to tooth or restoration
  • not cariostatic
  • final set takes 24 hours
  • brittle
  • opaque
23
Q

what are the advantages with zinc polycarboxylate cement?

4

A
  • bonds to tooth surface
  • less heat from reaction
  • low initial pH but returns to neutral quickly
    cheap
24
Q

what are the disadvantages with zinc polycarboxylate cement?

5

A
  • difficult to mix
  • difficult to manipulate
  • soluble in oral environment at lower pH
  • opaque
  • lower modulus and compressive strength than zinc phosphate
25
Q

what can ZOE and related materials be used for?

4

A
  • linings/base in deep cavities
  • temporary restorations
  • root canal sealer
  • periodontal dressings
26
Q

what is and what kind of reaction occurs with ZOE?

2

A

acid base reaction and chelating reaction
ZnO + 2C10H12O2 -> C20H24O5Zn
zinc oxide base + eugenol acid = zinc oxide eugenolate (ZOE)

27
Q

what are the properties of ZOE?

6

A

adequate working time ✓
relatively rapid setting time ✓
low thermal conductivity ✓
radiopaque ✓
low strength ✖
high solubility - eugenol is constantly released and replaced with water which disintegrates it but reduced pulp pain ✓✖

28
Q

what is ZOE not used with?

A

composite resins as eugenol inhibits setting

29
Q

what is the difference between resin modified ZOE and ZOE?

4

A

resins added to powder and liquid
* gives a stronger backbone
* increases compressive strength
* greatly decreases solubility

30
Q

what are the consituents of ethoxybenzoic cement (EBA ZOE)?

A

powder
* ZnO
* quartz or alumina
* hydrogenated rosin
liquid
* eugenol
* ethoxybenzoic acid

31
Q

what is the setting reaction for EBA ZOE?

A

same as with ZOE but with EBA
ZnO + C10H12O2 + C9H10O3 -> C19H22O6Zn
zinc oxide base + eugenol + ethoxybenzoic acid = ethoxybenzoic acid zinc oxide eugenolate

32
Q

what is the importance of EBA and quartz/alumina in EBA ZOE?

2

A

EBA - reactive
quartz/alumina - reinforcing

33
Q

what are the properties of EBA ZOE

2

A
  • stronger than ZOE or RMZOE
  • less soluble
34
Q

what are the advantages of glass ionomer liners?

6

A
  • bonds to and seals dentine
  • bonds to composite resin
  • releases fluoride over time and can be cariostatic
  • easy to use
  • light cured - command set
  • long working time and short setting time
35
Q

what are the properties of glass ionomer liners?

6

A
  • thermal conductivity and diffusivity lower than dentine
  • thermal expansion similar to dentine
  • compressive strength higher than ZnO materials
  • radiopaque
  • good marginal seal
  • less soluble than other liners
36
Q

what are the guidelines for lining?

3

A
  • cavities in dentine - RMGIC lining fro amalgam and larger composite cavities
  • calcium hydroxide should only be used when cavity reaches pulp
  • calcium hydroxide should be covered with RMGIC prior to final restoration

BDS2 CDS Dental Materials Science (5 decks)

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