L9 Inlays, onlays, overlays, pinlays and partial crowns Flashcards
What materials can these restorations be made of?
- Ceramic/porcelain
- Composite
- Gold
What type of coverage is offered by an inlay, onlay, overlay, pinlay and partial crown?
What are the differences between an indirect and direct restoration?
- Indirect requires 2 or more visits, direct 1
- Indirect has wider material choice, direct are limited to plastic materials
- Indirect require removal of undercut, direct can be less invasive
- Aesthetics are dependent on lab for indirect, operator for direct
- Indirect has no moisture or access issues in the construction, only the fitting
- Indirect can outlast direct material wear
- Indirect margins can degrade through lysis from saliva and food creating stain
- Direct has better supragingival success
- Direct wear resistance lower than metal ceramic or lab cured composite
- Direct margin degradation is slightly easier to resolve than ceramic for example
What are the advantages of an aesthetic inlay over a plastic restoration or crown?
- Reduce shrinkage
- Control occlusion and contact points
- Simplified technique for larger cavities where you would need to rebuild cusps and consider c-factor
- More aesthetic
- Potentially improved longevity but inconclusive
What are the disadvantages of an aesthetic inlay over a plastic restoration or crown?
- More expensive
- 2 stage procedure (some practices can offer same day restorations e.g. pt waits an hour or so)
- Problems of temporisation if pt is returning at later date
- Bonding is very technique sensitive, rigorous moisture control needed
What restoration is shown on this first premolar? What features would the dentist have considered when preparing this tooth?
Ceramic inlay.
- Walls must all be divergent (narrow base, wider opening)
- All cavosurface margins must be smooth (no sharp transitions)
- Any undercuts filled with plastic restorative materials compatible with adhesive needed for inlay
- Restoration sealed and cemented under rubber dam
What is an inlay-onlay?
- Also called a hybrid cusp covering overlay
- Indirect restoration
- Like an inlay but also covering a/some cusps
Why would you restore a tooth with a composite inlay instead of a direct restoration?
What type of restoration would this tooth require?
An overlay or 3/4 crown hybrid
What does this image show?
- Margin deterioration and staining
- Ingress of stain and moisture
- Could be due to hydrolysis of the luting cement (cement breakdown due to saliva and bacteria presence)
- Could be potential microchipping of the enamel or restorative material
Why would you choose to construct an indirect restoration out of gold instead of porcelain?
- Gold can be placed in very thin sections so can be used for very margins
- Gold is slightly ductile so will adapt to the margin if there is a small error
- Porcelain is more brittle and so can discolour at the margin over time due to the breakdown of the bond and ingress of stain
Why are gold onlays ideal for restoring tooth wear?
What cements are used for indirect restorations?
Porcelain and composite:
- Calibra
- Nexus
- Panavia
- Rely X unicem
Gold:
- Panavia 21
- Rely X unicem
What materials can be used to temporise a cavity?
- PolyF
- Kalzinol
- Cavit
- Luxatemp and clip
- Integrity
Describe PolyF as a material for temporisation.
- Very strong material
- Difficult to removal so not a great temporary material
- Needs to be cut out with bur or ultrasonic carefully without damaging the preparation which is challenging
What are the general measurements for inlay/onlay cavity preparations?
What are the general cavity preparation design considerations for indirect restorations?
What common cavity errors are made with restorations?
