The failure of directly place restorations Flashcards
why do we restore teeth?
To stop lesion progression and prevent its recurrences
Restore occlusion and function
Restore Aesthetics
Maintain the physiological integrity of the teeth with the adjacent hard and soft tissues
Restore patient comfort and satisfaction
how do we measure how long it last?
Success
Survival rate
Longevity
Failure
Amalgam
Medial survival rate?
annual failure rate?
Median survival rate 15 years in one study and up to 22.5 years in another study
Annual failure rates of 3%
some causes of amalgam failure?
Incorrect case selection Cavity preparation: inadequate retention Poor matrix preparation Amalgam manipulation Contamination Failure to condense Improper finishing and polishing procedures Post-operative pain : inappropriate lining material Microleakage, ditching and creep Tarnish and corrosion Faulty contacts
Composite
Early composite showed a failure rate of?
This has drastically improved with the newer products
Studies show median survival of?
Annual Failure rate of?
Failure rates as high as 50% after 10 years
Studies show a median survival of 8 year
The annual failure rate of 2%
Causes of composite failure?
Incorrect case selection
The difficulty to obtain long term adhesion between the composite resin and the dentine, failure at the gingival margin is not uncommon
Failure to light cure composite in increments
Contamination of the material: moisture control
Polymerization shrinkage causing caries, fracture, sensitivity, marginal deficiency
Glass ionomer
Median survival rate?
Annual failure rate?
The median survival of 30-42 months in permanent teeth.
Their annual failure rate when used alone as a restorative material is estimated to be 7%.
Causes of failure of Glass ionomer
Case selection: Failure of glass ionomer restoration is generally the result of poor handling of the material at the time of placement or excessive occlusal loads
The implication of restorative failure?
Time Cost Material Choice Technique Remaining tooth structure
Factors affecting the success and failure of restorations?
Patient factors
Operative factors
Material factors
patient factors that affect success and failure of restoration?
Caries risk: Oral hygiene, diet ,regular dental check up Heavy occlusal forces: bruxism Tooth to be restored Cavity size and location Pulpal health Periodontal health Allergies
what allergies can affect the success and failure rate of restoration?
Oral lichenoid reaction of oral mucosa against amalgam or gold alloys
Allergy to amalgam or gold alloys, or sensitivity to HEMA in resin composites/ fissure sealants
Operative factors that affect the success and failutere rate of restoration?
The correct choice of restorative dental material for the situation
Cavity design ,retention, removal of unsupported enamel and weakened cusps
The optimal handling of that material
The use of exemplary clinical techniques in placement & finishing
material factors that affect the success and failure rate of restoration?
compressive strength
rigidity (modulus of elasticity)
surface hardness and surface wear characteristics
flexural strength
Material Factors – microleakage?
Thermal expansion Adhesion property Resistance to fatigue Solubility Ditching and creep
Why does ditching and creeping happen?
Ditching and creep are a result of the slow deformation of amalgam placed under constant load, When the load is less than necessary to produce fracture ,causing marginal breakdown. Mostly seen when using amalgam with gamma 2 phase products.
What is ditching?
Ditching or crevicing is breakage of a thin edge creating an irregular V shape crevice
what is creeping?
Creep happens when the corrosive products leak and fill the gap between the tooth and the restoration
ways that restroration fail?
Disease
Caries Tooth wear Periodontal disease Pulpal problems Trauma
ways that restroration fail?
Technical failure
Fractured restoration Marginal breakdown Tooth fracture Defective contours Failure of retention
How to detect restoration failure?
Patient symptoms : pain, aesthetic concerns , discoloration, fracture
Visual & tactile inspection : caries,marginal breakdown,lost restoration,fractured restoration,excessive discoloration,open contacts and overhangs
Transillumination
Radiographic examination : caries,apical and periodontal status,overhangs
Occlusal examination : occlusal contact against the opposing structure,loss of anatomy
Primary caries
Secondary/ recurrent caries
Diagnosis should always be supported with radiographic findings, presence of soft dentine at excavation etc.
At a new site on the tooth
At the margin or under a restoration
Risk of secondary caries was found to be 3.5x greater for composite than
amalgam restorations (Bernardo et al. 2007)
Caries left behind after the initial restoration phase
Asthetic problem with composite:
cause of colour change:
A mismatch in the colour at the time of placemen
Colour/ profile changes with time
loss of marginal integrity
microleakage of composite resin restorations
marginal staining
loss of surface lustre & polish
Repair the restoration if there is:
No obvious spreading of gross caries that would structurally undermine the restoration or remaining tooth structure
Sufficient volume of retained restoration remaining and it is strong enough to resist masticatory forces
The possibility to bond or mechanically interlock the new restoration into the ‘old’ restoration and tooth
No potential aesthetic mismatches between the ‘new’ and ‘old’ materials
Summary:
Ultimately all restorations will fail with time
A good clinical technique with careful use and manipulation of the appropriate restorative material is important to minimise failure and maximise longevity of your restorations
Beware of causing iatrogenic damage to adjacent tooth enamel, restorations or gingival tissues
Always identify the cause of failure before replacing any restoration
The clinician has a responsibility to inform/ show the patient how to look after their teeth & restorations in terms of diet, OH techniques, and use of fluoride toothpastes or supplements
