Inlays and Onlays Flashcards
What is an inlay?
Intracoronal restorations made indirectly to strengthen and repair decayed or damaged posterior teeth
How are inlays and onlays different?
Onlays extend over weakened cusps to provide extra protection
Why were early ceramic inlays not very successful?
Marginal integrity issues
No bond between restorative material and tooth tissue possible
Luting cement washed out of marginal discrepancies
Discolouration, marginal openings and 2ndry caries
More aggressive to opposing dentition
What are the indications for inlays and onlays?
As an alternative to amalgam
- Amalgam toxicity concerns
- Lichenoid reactions
When resin composite not indicated
- Size of cavity
- Previously failed composite restorations
- Aesthetics
When long lasting aesthetic result aimed
Conservative type of indirect restoration
Indications for onlays?
Teeth with larger restorations, but sound buccal and lingual walls
- Endodontically treated teeth
- Wider MODs
- MODs in premolars
Indications for inlays?
Low caries rate
Small MO or DO cavities in molars and premolars
Conservative MOD in molars
Contraindications to inlays and onlays?
Poor OH
Pt with excessive occlusal loading e.g. bruxism
What materials are used for inlays and onlays?
Gold
Ceramic
Resin composite
Advantages of inlays and onlays?
Conservative Marginal integrity Good wear Corrosion resistant Relative ease of handling Excellent physical and mechanical characteristics Excellent survival rates (25-40yrs)
What to consider with inlays and onlays?
Cost
Technique sensitivity - clinical and laboratory
Poor aesthetics
Wedge effect of inlay
Advantages of adhesive technologies (e.g. composite)?
Aesthetic restorations
Stronger and more stable material (no wear; discolouration)
Marginal leakage due to polymerisation shrinkage is minimal
Conservative ceramic restorations
What to consider with adhesive technologies?
Ceramic = fragile = handle with care
Sensitive technique
- Intraoral adjustment contraindicated until restoration is bonded
- After bonding, adjustments can compromised aesthetics
- When bonded certain stages are required to guarantee the result
Bonding indirect composite is a problem
Wear of the luting agent can lead to marginal gaps and 2ndry caries
Longer tx: indirect restorations - 2 visits unless CAD/CAM used
Cost
What are the types of ceramic?
Feldspathic glass ceramic
Leucite reinforced ceramic
Lithium disilicate ceramic
Types of indirect resin composite?
Hybrid composite
Ceromers
Ceramic optimised resins
Paradigm MZ100 (3M ESPE)
BelleGlass (Kerr)
Targis (Ivoclar)
Fabrication techniques for gold inlays/onlays?
Lab made - lost wax, casting