Failure of Restorations Flashcards
What does Longevity Depend on? (3) (7)
Success of the restoration
Survival Rate
Failure - inability to meet desired outcome
- compressive strengths
- surface wear
- thermal expansion
- adhesion
- fatigue resistance
- creep
- ditching = formation of a v shape gap between tooth and amalgam filling - food packing - with the old amalgam when gamma 2 was produced
What is the Survival Rate (years) and Annual Failure of Amalgam (%)? How Does Creep Extend this?
SR = 15-22 years
AF = 3%
creep = corrosive product leak
- has the ability to seal itself over time after erosion
- fills the interface gap between restoration and tooth surface
What is the Survival Rate and Annual Failure of Composite?
SR = 8 year
AF = 2%
after 10 years, failure is 50%
What is the Survival Rate and Annual Failure of GIC?
SR = 2.5-3.5 years
AF = 7%
What are the Reasons for Amalgam to Fail? (10)
- incorrect case selection
- cavity prep
- poor matrix
- amalgam manipulation
- contamination
- failure to condense
- improper finishing
- micro leakage and creep
- tarnish and corrosion
- faulty contact points
What are the Reasons for Composite to Fail? (6)
- incorrect case selection
- contamination
- moisture control
- shrinkage
- poor long-term adhesion
- light curing
What are Reasons for GIC to Fail? (2)
- poor handling
- excessive occlusal loads
How can you Identify Failure? (7)
- Disease - if still present after restoring
- Technical - marginal breakdown, defective contour
- Radiograph - overhang, caries
- Occlusal Examination - loss of anatomy
- Symptoms
- Transillumination
- Aesthetics - colour change
What Patient Factors can Lead to Restoration Failure? (5)
caries
OHI
heavy occlusal forces
cavity size and location
pulpal health
Why would you need to Replace Failed Restorations
- tooth fracture
- plulpal exposure
- caries risk
When would you choose to Repair, rather than Replace a Failed Restoration? (4)
- no risk of caries
- sufficient volume of retained restoration remains and strong for forces
- if new restoration will bond to old
- if the aesthetic matches
