Security and Liners Flashcards Preview

IODC - Dentures > Security and Liners > Flashcards

Flashcards in Security and Liners Deck (20)
Loading flashcards...
1
Q

What 3 surfaces must you consider?

A

Fitting, oclusal and polished

2
Q

When is denture retention?

A

Ability to resist those forces attempting to displace the denture at right angles to the supporting tissues

3
Q

What factors are involved in denture retention?

A

Effectiveness of fitting surface and peripheral seal
Adaptation of fitting surface to underlying ridge
Extension (buccal sulcus) - achieve good peripheral seal

4
Q

What is denture stability?

A

Ability to resist those forces attempting to displace it in directions, other than right angles to the supporting tissues

5
Q

What factors are involved in denture stability?

A

Size and shape of residual alveolar ridge
Occlusal loads
Tissue compressibility
Contacts - premature contacts can cause denture to tip

6
Q

What are the 3 types of liners?

A
  1. Permanent
  2. Semi-permanent
  3. Temporary
7
Q

What are permanent liners made from and where used?

A

Autopolymersing PMMA
Heat cured PMMA

Lab or chair side cure

8
Q

Indication hard permanent liner?

A

Relining dentures
Addition to dentures
Placement of post dam

9
Q

Indication for soft permanent liners?

A

Relining dentures
Tender mandibular ridge
Over mental foramen

10
Q

How thick does soft liner need to be?

A

4mm at least

11
Q

How to carry out softeners chair side?

A

Remove undercut (most seen anterior area) or extend any short area
Use zinc oxide eugenol for impression - closed mouth technique
Perforation needed to minimise thickness of any material - may result increase face height

12
Q

Why is close mouth technique used?

A

Avoid increasing vertical dimension

13
Q

Problems with auto-polymerising liners?

A

After a while become distinguishable from rest of denture - stain due porosity
Some contain plasticiser and remain relatively soft for period of months

14
Q

How to use auto-polymerising liners chair side?

A

Dispensed as powder/liquid
Good handling properties and quick set
Used: liners, addition and post dam

15
Q

How are heat-cured silicones used?

A

Cured in labs
Processed onto denture in lab
Bonding critical - best bond to fresh acrylic

16
Q

Problems with heat-cured silicones?

A

Last 6month-3years
Plasticisers can leach out - become harder
Problem - pt can find hard to adjust to hard denture

17
Q

Benefits of auto-polymerised silicones?

A

Can be cured chairside
Softer than lab cured
More compatible w/ mucosa

18
Q

What are the classifications of temporary liners?

A

Soft liners
Functional impression materials
Tissue conditioners

19
Q

What is composition of temporary liners?

A

PEMA, dibutyl phthalate, ethyl alcohol, benzyl salicylate

20
Q

Indications for temporary liners?

A

Immediate dentures
Relief of pain
Conditioning of tissues
Functional impression material