provisional extra-coronal restorations Flashcards
what are the clinical stages of provisional extra coronal restorations
- Preparation
- Temporisation
- Impressions and registration
- Cementation
- Success of each stage is dependent on success of preceding stage
why is tooth preparation not ideal
- compromises aesthetics in smile line
- occlusion reduction in function
- destabilises occlusion
what should provisional restorations do
- have a good marginal fit
- be well contoured
- cleansable and maintained by patient
what happens if we have a poorly fitting contoured provisona
- patient unable to clean = caries, periodontal disease
- poor moisture control
- gingival overgrowth
what must provisionals do
- establish and/or maintain dental aesthetics, mimicking either the original tooth or a definitive restoration
- prevent sensitivty
- allow ‘optimum home care’
- prevent micro leakage
what are some additional uses of provisional restorations
- isolation for RCT
- matrix for core build-up
what are desirable characteristics of provisional materials
- non-irritant
- low temperature rise during setting
- dimensionally stable
- adequate working time
- adequate setting time
- adequate strength and wear resistance
- good aesthetics
what are the different types of provisional restorations
- Custom formed
* Preformed
which type of provisional restorations are preferred
- customer formed
- can be technically demanding however
- fits better and looks better
what materials are used for custom provisional restorations
- typically made out of composite
- chemically cured bis-acrylic resin
why is composite good to use for provisionals
- customisable = can add to it or take away
- easy to adjust
what is a svensen gauge
- pincers to clamo over restoration and needle slide up the ruler to show how thick it is
- can use temporary restoration to check how much tooth you have removed
what type of impression do we take for temporary restorations
- sectional impression
- don’t need full arch
what materials are used for an impression
- addition cured silicone putty = ‘President’
- alginate
- softened modelling wax
why is president a good impression
- can be disinfected
- can be reused
- resistant to tearing
- doesn’t shrink of expand over time
- mainly used
what are the properties of softened modelling wax
- easy to adjust and smooth
- cheap
- unsuitable for deep undercuts
- distorts
- cannot be reused
- easy to use
how are custom made vacuum formed stents made
- sectional impression
- prepare tooth for chosen restoration
- syringe bi-acrylic composite resin into bracket table or mixing pad
- syringe material into sectional impression of tooth that has been prepared
- relocate impression in the mouth
- remove completely
- remove flash and ledges
- confirm tooth preparation
- check marginal fit and occlusion in situ
- check aesthetics
- cement provisional restoration with temporary luting cement
how full do you fill the impression with Protemp
- 3/4 full
what pressure is used to seat temporary restoration
- finger pressure
when may we need to reestablish occlusion and aesthetics
- loss of original tooth form = from wear
- for guidance
what type of guidance is preferable
- canine
how do we form guidance
- produce on crowns
- diagnostic wax-up = take upper and lower impressions of patient with toothier
- articulated study models = on articulators
- Facebow registration required if changing occlusion