ICP-23 Failure of Restorations Flashcards
How long do amalgam fillings last
At 10 years <10% of restorations replaced
What effect does operator skill, size of restoration and type of alloy have on how long amalgam fillings last
- Operator skill = no effect
- Size of restoration = no effect
- Dispersed phase high Cu alloys tend to last longer
How long do composite with dentin bonding fillings last
Failure in cervical cavities typically begins <1yr
What about composite with dentine bonding can improve its survival
- Improved survival with acidic primer
- Enamel etching and mechanical retention improves retention
- Dentine bonding reduces post-operative pain
What does it mean if a restoration has failed
- Secondary/recurrent disease: invasive caries in dentine, pulpal necrosis
- Loss of function: loss of restoration, loss of surrounding tissue
- “Inevitable” progression to caries
- Microleakage causing sensitivity or pain
- Appearance unacceptable to patient
What are the symptoms of secondary invasive caries in dentine
- Usually none
- Discolouration (anterior)
- Symptom of pulpitis
What are the signs of secondary invasive caries in dentine at the restoration margin
- Visual (not approximally)
- Radiography (approximatif)
- Tactile
What are the signs of secondary invasive caries in dentine in deep tissue
- Visual (sometimes)
- Radiography (sometimes)
What are the symptoms of secondary pulpal necrosis
e.g. of pulpitis
What are the signs of secondary pulpal necrosis
Loss of vitality on sensibility testing +/- peri-radicular radiographic change
What is a symptom/sign of loss of function of a restoration
- Restoration can be loose or lost
- Fractured tooth/cusp causing loss of occluding surface
What are the signs of the “inevitable” progress to caries
- Fractured restoration permitting microleakage
- Loss of marginal integrity permitting microleakage
What does microleakage of a restoration cause
Microleakage will result in bacterial ingress and caries which causes failure of the restoration
How might the appearance of a restoration become unacceptable to a patient
- Marginal staining (anteriors)
- Discolouration of anterior material
- Contrast with “normal” darkening of tooth
- Gingival recession (darker roots)
- Desire for “white fillings”
What factors can cause a restoration to fail
- Patient factors
- Operator factors (iatrogenic)
- Materials factors
- Chance e.g. trauma
What are some patient factors that can cause a restoration to fail
- Cariogenic Factors: Diet, Plaque, Saliva/xerostemia, Poor oral hygiene
- Para-functional habits
- Appearance unacceptable
NB - when giving diet and hygiene advice, customise your advice to your patient lifestyle
What are some operator factors that can arise from errors in planning that lead to a failed restoration
- Failure to promote prevention
- Failure to check occlusion before management of tooth
- Failure to take account of “whole patient” i.e. management of caries/periodontitis risk
- Inappropriate restoration for tooth or situation
- Inappropriate restorative material
What are some operator factors that can arise from errors in execution that lead to a failed restoration
- Damage to pulp-dentine complex
- Leaving infected carious tissue
- Bad cavity design for restorative material
- Failure to reduce height of tall thin cusps in occlusion
- Incorrect use of material
- Failure to give self care instructions
- Using composite resin when the pulpal margin is in dentine
What material factors can lead to failure of a restoration
Causes of failure differ between materials:
- Fracture
- Corrosion, dissolution, chemical degradation
- Wear
- Discolouration/staining
- Some materials normally have much greater longevity than others
Should you repair or replace a failed restoration
Flawed data suggests:
- Repairs = similar short term survival to replacement
- Repairs are less invasive
How to decide repair/replacement with the patient
- Explain treatment options and associated risks
- Discuss current state of evidence base underpinning treatment options
- Combine clinical expertise with patient’s informed choice
What are some of the ways that you can improve composite restorations
- Work on a clean tooth surface - clean surface with wet pumice slurry
- Etch only area you’re working on, wash thoroughly
- Check for dry air, line in your three in one
- Enamel should be completely dry, dentine should not be desiccated
- Rub Primer and bonding agents on the surface to improve penetration
- Point the centre of the beam of the light cure on the area being cured
- Use small increments and shape appropriately to minimise cutting back
- Polish
- Don’t paint unfilled resin/bond on your finished restoration
