FP - provisional restorations Flashcards
list 5 functions of a restoration
- protect pulp from thermal, mechanical, electrical and chemical trauma
- maintains the position of the tooth in occlusion
- maintains the periodontal health of the tooth
- restores the aesthetic appearance of the tooth
- protects any root canal filling from coronal leakage
when are provisional restorations required (for fixed pros)?
provisional crowns
provisional bridges
provisional dentures/ overdentures
what are the 5 methods to create a provisional restoration?
- pre-operative putty impression
- pre-formed crown
- pre-operative wax-up followed by duplication and vacuum-formed stent
- free-hand bis-acryl resin
- use the old crown if there is one
what are the 4 materials used for pre-formed crowns?
polycarbonate
cellulose-acetate
composite
(metal)
when would metal be used for a pre-formed crown?
hall crowns (stainless steel)
you are going to place a crown on a tooth, you dont want to reproduce the tooth in its current shape. How will you create the provisional restoration?
modify the tooth and copy this shape
pre-op model with wax registration - wax up then duplicated in stone and mould made
use the vacuum-formed mould to make the composite additions
crown preps and provisional crowns are made using the same mould
what is protemp? and give another name of a product the same
chemically-cured bis-acryl composite resin
Integrity (Dentsply)
what material goes in to pre-operative putty?
chemically cured bis-acryl composite resin
(ProTemp or Dentsply)
what material is used for a polycarbonate preformed crown?
“directa”
what is a polycarbonate “directa” preformed crown filled with?
poly ethyl methacrylate (TRIM)
give a unique property of trim
it is haemostatic
what are cellulose-acetate preformed crowns?
plastic moulds
what are cellulose-acetate preformed crowns filled with?
ProTemp
what are properties of composite preformed crowns?
half cured so are malleable and mouldable
long term - 2- 4 years
what technique can be used to make provisional restorations for multiple teeth where we want to change the occlusion?
pre-operative wax-up followed by duplication and vacuum-formed stent
what technique for provisional restoration can be used as a last resort when you can get no matrix in place?
free-hand bis-acryl resin
when can you use a provisional post crown?
when existing root canal is satisfactory
simple replacement of post crown only
NOT when undertaking RCT or replacing root canal filling
when would you want to use a provisional overdenture?
easy access to root surface for RCT or re-RCT
less coronal leakage during tx
likely better long term result
what happens to the provisional if the crown prep is undercut?
it will not withdraw from the prep
it will tear as withdrawn
how thick should an ideal provisional crown be?
more than 0.5mm thick
list the therapeutic uses of provisional restorations
improve gingival/ perio health prior to taking imps
improve speech difficulties
improve appearance of the final restorations
how may provisional restorations improve gingival/ perio health?
better contour allows access to cleaning and improved gingival health
how may provisional restorations improve speech difficulties?
changing the contours of palatal surface of anterior teeth
then copy successful prov rest contour for the definitive
at what stage should you make the provisional restoration?
after tooth prep
before imps
