Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
18 Cards in this Set
- Front
- Back
|
Type of polymerisation in acrylic polymerisation
|
Free radical addition
|
|
|
4 setting stages in acrylic polymerisation?
|
Creamy -> Sandy -> stringy -> doughy
|
|
|
What is activator in acrylic polymerisation?
|
Peroxide
|
|
|
What happens in activation step of acrylic polymerisation?
|
Peroxide forms radical
|
|
|
Describe structure of acrylic
|
Matrix of new PMMA surrounding beads of original PMMA with interpenetrating network formed at interface
|
|
|
Describe relationship between temp of cure, chain length, residual monomer and Tg
|
High temp cure = High chain length = Low residual monomer = High Tg
|
|
|
What is crazing?
|
Lots of surface cracks from taking out frequently and allowing to try, introduces sites of crack initiation
|
|
|
What are temporary denture soft liners, elastic, plastic or viscoelastic?
|
Viscoelastic
|
|
|
Describe what is in powder and liquid of a temp liner/tissue conditioner
|
Powder = Higher methacrylate
Liquid = Plasticizer and alcohol |
|
|
Describe setting reaction of a temp liner/tissue conditioner?
|
No chemical reaction, plasticiser is just absorbed, then eventually all leaches out and needs replacing
|
|
|
How shouldn't you clean a denture with a soft liner on it?
|
Oxidising cleaner
|
|
|
What is different about acrylic permanent soft liners to normal denture acrylic?
|
Soft liners have less filler and more plasticisers to make them have a low Tg
|
|
|
What are acrylic denture soft liners, elastic, plastic or viscoelastic?
|
Viscoelastic
|
|
|
What are silicone denture soft liners, elastic, plastic or viscoelastic?
|
Elastic
|
|
|
What material are cold cured condensation silicones used for denture linings the same as?
What do they release as a condensation product? What catalyst do they have? |
Impression silicone
Alcohol Tin |
|
|
What material are addition siliones used for denture linings the same as?
What catalyst do they have? |
Pt
|
|
|
What is different to the heat cured silicones used for denture linings compared to normal silicones?
|
Methacrylate terminated
|
|
|
Differences in ageing between silicone and acrylic denture liners?
|
Silicones remain soft
Acrylics lose plasticiser and harden |
