The failure of directly place restorations

Question 1

why do we restore teeth?

Answer 1

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

Question 2

how do we measure how long it last?

Answer 2

Success
Survival rate
Longevity
Failure

Question 3

Amalgam
Medial survival rate?
annual failure rate?

Answer 3

Median survival rate 15 years in one study and up to 22.5 years in another study 

Annual failure rates of 3% 

Question 4

some causes of amalgam failure?

Answer 4

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

Question 5

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?

Answer 5

Failure rates as high as 50% after 10 years  

Studies show a median survival of 8 year
The annual failure rate of 2%

Question 6

Causes of composite failure?

Answer 6

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

Question 7

Glass ionomer
Median survival rate?
Annual failure rate?

Answer 7

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%.

Question 8

Causes of failure of Glass ionomer

Answer 8

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

Question 9

The implication of restorative failure?

Answer 9

Time
Cost
Material Choice
Technique
Remaining tooth structure

Question 10

Factors affecting the success and failure of restorations?

Answer 10

Patient factors
Operative factors
Material factors

Question 11

patient factors that affect success and failure of restoration?

Answer 11

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

Question 12

what allergies can affect the success and failure rate of restoration?

Answer 12

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

Question 13

Operative factors that affect the success and failutere rate of restoration?

Answer 13

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

Question 14

material factors that affect the success and failure rate of restoration?

Answer 14

compressive strength
rigidity (modulus of elasticity)
surface hardness and surface wear characteristics
flexural strength

Question 15

Material Factors – microleakage?

Answer 15

Thermal expansion
Adhesion property
Resistance to fatigue
Solubility
Ditching and creep

Question 16

Why does ditching and creeping happen?

Answer 16

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.

Question 17

What is ditching?

Answer 17

Ditching or crevicing is breakage of a thin edge creating an irregular V shape crevice

Question 18

what is creeping?

Answer 18

Creep happens when the corrosive products leak and fill the gap between the tooth and the restoration

Question 19

ways that restroration fail?

Disease

Answer 19

Caries
 Tooth wear
 Periodontal disease
 Pulpal problems
 Trauma

Question 20

ways that restroration fail?

Technical failure

Answer 20

Fractured restoration
 Marginal breakdown
 Tooth fracture 
 Defective contours
 Failure of retention

Question 21

How to detect restoration failure?

Answer 21

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

Question 22

Primary caries

Secondary/ recurrent caries

Diagnosis should always be supported with radiographic findings, presence of soft dentine at excavation etc.

Answer 22

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

Question 23

Asthetic problem with composite:

cause of colour change:

Answer 23

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

Question 24

Repair the restoration if there is:

Answer 24

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

Question 25

Summary:

Answer 25

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