CSA failure of restorations

Question 1

Why do we restore teeth?

Answer 1

• improve aesthetic shape/shade/angulation
• function
• Stop lesion progression and prevent its recurrence
• Restore occlusions/ health of periodontium
• Restore patient comfort and satisfaction

Question 2

what depends on how long do restorations last?

Answer 2

o Success – Restoration should fulfil objective
o Survival rate – How long does restorations last
o Longevity – How long does restoration last?
o Failure – Inability to meet desired outcome

Question 3

What is median survival rate for amalgam

Answer 3

15 years

Question 4

What is amalgam recommended for ?

Answer 4

posterior teeth with heavy occlusal forces and patient with high caries risk

Question 5

What is failure rate of composite?

Answer 5

50% AFTER 10 YEARS

MEDIAN survival is 8 years

Question 6

what is median survival of GIC?

Answer 6

30-42 months in permanent teeth

Question 7

What can’t GIC withstand easily?

Answer 7

occlusal forces

Question 8

when does amalgam have a smaller survival rate?

Answer 8

for smaller cavities

Question 9

what are the implications of restorative failure?

Answer 9

time/cost/material choice/technique/remaining tooth structure

Question 10

What factors affect restoration longevity?

Answer 10

o Patient factors
o Operative factors
o Material factors

Question 11

What are patient risk factors?

Answer 11

• Caries risk:
• Heavy occlusal forces:
• Tooth to be restored
• Cavity size and location
• Pulpal health
• Periodontal problems
• Allergies

Question 12

What sort of heavy occlusal forces are there?

Answer 12

bruxism, risk of fracture under heavy load

Question 13

what does a failed restoration on anterior teeth mean?

Answer 13

patient will seek treatment earlier

Question 14

What does location of cavity mean?

Answer 14

cavity near gingival margin affected by moisture control

Question 15

What sort of allergies are there?

Answer 15

• Oral lichenoid reaction

* Allery to amalgam or gold alloys, or sensitivity to HEMA in resin composites/fissure sealant

Question 16

What are the allergies usually like?

Answer 16

painless and benign

Question 17

What are operative factors to consider?

Answer 17

• know qualities and properties of material
• Correct cavity design
• Optimal handling of material
• Use of exemplary clinical techniques in placement & finishing

Question 18

What is correct cavity design for amalgam?

Answer 18

undercuts for amalgam & must be deeper than 2mm

o Retention/ Removal of unsupported enamel and weakened cusps

Question 19

What are material factors to consider?

Answer 19

• Thermal expansion
• Compressive strength
• Rigidity (modulus of elasticity)
• Surface hardness and surface wear characteristics
• Flexural strength

Question 20

What does thermal expansion lead to?

Answer 20

micro leakage and fracture

Question 21

what is compressive strength ?

Answer 21

amount of force material can take before breaks

Question 22

What are factors linking to micro leakage?

Answer 22

adhesion property , e.g. composite has a good bonding to tooth so less micro

Question 23

Does amalgam have good adhesive properties?

Answer 23

ability to seal itself around margins, known as creep

Question 24

What does creep reduce for amalgam?

Answer 24

secondary caries

Question 25

what can form between restorations and tooth surface over time?

Answer 25

gaps

Question 26

What is creep ?

Answer 26

pulling away of restoration due to occlusal forces

Question 27

what is a result of creep?

Answer 27

ditching , food packing can occur here

Question 28

Way in which restorations fails due to disease?

Answer 28

``` o Caries o Tooth wear o Periodontal disease o Pulpal problem o Trauma ```

Question 29

What can overhanged restorations act as ?

Answer 29

PFS

Question 30

Way in which restorations fail due to technicalities ?

Answer 30

o fractured restoration o Marginal breakdown (micro leakage o Defective contours o failure of retention

Question 31

How do you detect a restoration failure?

Answer 31

* Ppt. symptoms: * Visual and tactile inspection: * Transillumiation * Radiographic examination * Occlusal examination:

Question 32

What are patient symptoms?

Answer 32

o Pain o Aesthetic concerns o Discolouration o Fracture

Question 33

What are visual and tactile inspections?

Answer 33

``` o caries, o Marginal breakdown o Lost restoration o Excessive discoloration o Open contacts and overhangs ```

Question 34

What is transillumination ?

Answer 34

light behind teeth and seeing

Question 35

What is radiographic examination?

Answer 35

caries apical and periodontal status, overhangs present

Question 36

What is occlusal examinatiion?

Answer 36

occlusal with adjacent teeth, State of tissue, Loss of anatomy of tooth

Question 37

what is the most common reason for restoration failure?

Answer 37

caries

Question 38

What is secondary caries?

Answer 38

caries next to a restoration

Question 39

How does secondary caries form?

Answer 39

o due to incorrect handling/packing/choice of material/dentist didn’t remove all the caries and sealed it up

Question 40

What is the risk for secondary caries like?

Answer 40

3.5 times greater for composite

Question 41

what are aesthetic reasons to why restorations fail?

Answer 41

``` •Causes of colour changes o Loss of marginal integrity o Micro leakage of composite resin restorations o Marginal staining o Loss of surface luster and polish ```

Question 42

When do we repair restoration?

Answer 42

o No obvious spreading of gross caries o Sufficient volume of retained restoration remaining and strong enough to resist masticatory forces o can bond new restoration into ‘old’ restoration and tooth o No aesthetic mismatches

Question 43

When do we replace a restoration ?

Answer 43

if caries is present