RP 4 - Relines, repairs and additions Flashcards
What is a reline?
adding new base material to the fitting surface of an existing denture in a quantity sufficient to fill the space which exists between the original denture contour and the altered tissue contour
(providing a new fitting surface for a denture or part of a denture)
What is a rebase?
replacing the entire denture base material of an existing denture
Are relines and rebases done chairside or in the lab?
reline - usually chairside
rebase - lab
What are the 3 categories of relines?
- temporary
- soft
- permanent
What are the features of a temporary reline?
no particularly resilient and will only last for a shortish period of time
What are the features of a soft reline?
provides some cushioning inside the denture
Where are the more resilient types of relines usually done?
in the lab rather than chairside
When may temporary relines be provided?
- tissue conditioning - when grossly ill fitting dentures or tissues very inflamed etc
- post immediate dentures
- after implant surgery
When may soft relines be provided?
- parafunctional habits e.g. bruxism
- very atrophic ridges
- cancer/cleft patients (obturator)
What are the downsides of soft relines?
plasticiser leaches, deteriorate/harden with time, harbours microorganisms
What 4 types of soft lining materials are available?
- heat cured acrylics
- self cured acrylics
- heat cured silicones
- self cured silicones
some can be used chairside and some need technical processing
Describe heat cured acrylics (as a soft lining material)
powder is methacrylate based (such as polyethyl methacrylate) activated by benzoyl peroxide in liquid containing monomer and plasticiser
Describe self cured acrylics (as a soft lining material)
like heat cured acrylics but rather than heat is is a tertiary amine that acts upon the benzoyl peroxide
Describe heat cured silicones (as a soft lining material)
processed against acrylic. contain a siloxane material and a filler of silica
Describe self cured silicones (as a soft lining material)
similar to impression materials for composition and setting
What type of soft lining material is coe-soft?
self cured acrylics (can be done chairside)
What type of soft lining is Molloplast B?
heat cured silicone (placed and processed in the lab)
What type of material are permanent relines typically made of?
usually hard acrylic (heat cured, usually placed in the lab)
What situations might permanent relines be used in?
- useful in peripheral seal problems
- correction of errors following inadequate master impression
- immediate/post-immediate dentures
- prolongs lifespan of some older dentures
What kind of denture would you consider for a rebase?
the denture is loose fitting, the teeth are not worn and are in good condition