COMPLETE DENTURES - SECURITY & LINERS

Question 1

retention definiton

Answer 1

• ability of denture to resist displacement in an axial direction away from the denture bearing tissues

Question 2

stability definition

Answer 2

• ability to resist forces attempting to displace the denture in directions other than at right angles to the supporting tissues
• lateral and antero-posterior movements

Question 3

types of liners

Answer 3

permanent (heat cured PMMA resins, chairside autopolymerising)
semi permanent (silicone based)
short term (acrylic resin chairside soft liner)
tissue conditioner

Question 4

what is heat cured PMMA lab liner used for

Answer 4

provision of a full reline to an existing denture

addition of flange extension to existing denture

Question 5

how to do lab liner PMMA

Answer 5

remove overextensions and sig undercuts reduced
ahdesive for silicone
none for ZnO
reline lower denture with light bodied silicone
allow perforations to allow flow of material

Question 6

indications for autopolymerising chariside permanent pmma liners

Answer 6

provision of partial reline to an existing denture (resorption post root extraction|)
addition of a flange correcting an underextension in exhisting denture
creation of a functional post dam in an unretetive exhisting denture
chairside pick up of locator housings in implant cases

Question 7

what can soft denture lines do

Answer 7

create a more uniform distribution of stress at the muscosa/denture interface

Reduce traumatic effect of
- thin atrophic mucosa
ridge atrophy or resorption
deep undercuts ect

Question 8

types of soft denture liners

Answer 8

silicone soft denture liners (lab)

acrylic soft denture liners (chairside)

Question 9

disadvantages of SDL (soft denture liners)

Answer 9

low resistance of colonisation by C albicans due to porosity
can discolour sig
debonding from acrylic denture base
swell due to water sorption
hardening and roughness due to leaching out of plasticisers
bitter taste
difficult to adjust

Question 10

ridge types where SDLs may be indicated

Answer 10

irregular ridge

atrophic ridge

Question 11

optimum thickness of SSDL (siliucone soft denture loner) and why

Answer 11

3mm
too thick increases OFH
too thin causes inadequate cushioning

Question 12

when is acrylic resin soft denture liners used

Answer 12

immediate dentures during a period rapid resoprtion of alveolar bone

Question 13

tissue conditioner use

Answer 13

cushion existing denture to relive inflammation
PEMA
reduces trauma of underlying soft tissues prior to provision of new prosthesis