Brainscape's Knowledge GenomeTM

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


See full index

Dental Materials Y3 > Temporary Soft Lining Materials > Flashcards

Temporary Soft Lining Materials Flashcards

1
Q

What is the function of Cold cure (RT) soft acrylics

A
  • Used to treat irritated mucosa that support a denture allowing it to heal
  • Absorbs some masticatory impact and distributes it evenly
  • Shock absorber and dat
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Do Cold cure (RT) soft acrylics generally have better or worse properties

A

CCSAs are usually worse

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

In what ways are CCSAs generally worse than heat cured acrylics

A
  • Contains 3-5% free (residual) monomer that can leach out
  • Higher water uptake
  • Poorer mechanical properties
    These are therefore temporary SLMs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe the composition of the powder phase of CCSAs (RT)

A
  • Poly ethyl methacrylate (PEMA)
  • OR a copolymer of butyl methacrylate and ethyl methacrylate
  • PMMA
  • Benzoyl peroxide initiator
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Describe the composition of the liquid phase of CCSAs (RT)

A
  • Ethyl Methacrylate AND/OR
  • Butyl Methacrylate AND/OR
  • Methyl methacrylate
    All liquids contain
  • Cross linking agent e.g. ethylene glycol dimethacrylate
  • Plasticiser e.g. citrate plasticiser/di-butyl phthalates
  • Tertiary amine e.g. N,N dimethyl-p-toluidine (DMPT)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is a potential drawback of MMA monomer

A

Can cause mucosal irritation

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

How do CCSAs compare to Tissue conditioners (similarities and differences)

A

Their function is similar but they differ like this:

  • CCSAs contain a polymerisable monomer in the liquid phase
  • CCSAs therefore set via a free radical addition polymerisation reaction
  • CCSAs last longer than TCs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are some advantages of using CCSAs (RT)

A
  • They’re viscoelastic materials
  • Compliant (soft)
  • Bonds to PMMA (denture base material)
  • Simple to use
  • Can be used chair-side
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are some disadvantages of using CCSAs (RT)

A
  • Lasts for 2-3 weeks
  • Releases residual monomer that can cause mucosal irritation
  • Porous, can allow ingress of microorganisms
  • Difficult to remove from the denture (due to bonds that may form with the PMMA on the denture base)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe the function of Tissue Conditioners

A
  • Treats irritated mucosa supporting the dentures by absorbing and distributing masticatory forces
  • Shock absorber
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How are Tissue Conditioners actually used in practice

A
  • In the treatment of denture related stomatitis
  • Denture liners - initially to treat traumatised tissue but remain on the denture as a liner
  • Functional impression material - created as the patient wears a provisional denture over 24 hours ish
  • Piezographs - impression moulded by tongue, lips and cheeks over 5-10 mins, recording of the denture space by means of pressure
  • Maxillofacial prostheses
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How are Tissue Conditioners dispensed

A

Powder and Liquid

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

Describe the composition of the powder phase of Tissue Conditioners

A
  • PEMA

- OR a copolymer of butyl methacrylate and ethyl methacrylate

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

Describe the composition of the liquid phase of Tissue Conditioners

A
  • Plasticiser e.g. dibutyl phthalate, benzyl salicylate OR acetyl tribute citrate
  • Ethanol (6-15%)
    NOTE: no monomer in liquid phase so no polymerisation reaction on setting
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Describe the setting reaction of tissue conditioners

A

Via Gelation:

  • Alcohol swells the polymer beads (chains)
  • This allows penetration by the plasticiser between the swollen polymer beads, allowing the polymer chains to move more easily
  • Gel is formed by polymer chain entanglement (physical process, not chemical)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What effects on handling and gelation will increasing the powder/liquid ratio with tissue conditioners have

A
  • Increase the viscosity of the gel
  • Affect its final compliance (softness)
  • Increase rate of gelation
17
Q

What does increasing temperature do to the setting process of tissue conditioners

A

increases the rate of gelation

18
Q

What effect does decreasing the molecular weight and particle size of the polymer powder have on the setting reaction of tissue conditioners

A

Both of these increase the rate of gelation

19
Q

What effect does increasing the amount of ethanol have on the setting reaction of tissue conditioners

A

Increased rate of gelation

20
Q

What is the benefit of CCSAs and TCs being viscoelastic

A

these materials can conform to the anatomy of an edentulous ridge with an applied force, spreading it out

21
Q

What are the advantages of Tissue Conditioners

A
  • Compliant (soft)
  • Bonds to PMMA (denture base material)
  • Simple to use
  • Can be used chair side
22
Q

What are the disadvantages of Tissue Conditioners

A
  • Hardens in the mouth - loss of ethanol and plasticiser into the oral environment
  • All ethanol lost within 24 hours
  • Possible toxicity of the plasticiser
  • Porous, can allow ingress of micro-organisms
  • Difficult to remove from the denture
23
Q

Do SLMs and TCs have high or low water uptake

A

High

24
Q

What can the high water uptake of SLMs and TCs lead to

A

Staining and microbial colonisation

25
Q

How can common denture cleansers affect SLMs and TCs

A

Adversely affect by bleaching (hypochlorites) or by causing roughening and bleaching (alkaline peroxide)

26
Q

What is the recommended way of cleaning your dentures

A

Brushing with soap

Dental Materials Y3 (9 decks)

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