Rest Failure

Question 1

4 REASONS REST + IMPLICATIONS

Answer 1

• Stop lesion progression + recurrence
• Restore occlusion + function + aesthetics  mastication+speech, shape+colour
• Maintain physiological integrity teeth w adj hard+soft tissue
• Restore pt comfort + satisfaction
• Implications = time, £, prep, mat choice, technique, replace= ↓remaining tooth structure

Question 2

REST LONGEVITY MEASUREMENTS
– poor case selection?

Answer 2

• Success = ability of rest, perform as expected
• Survival Rate = measure clinical performance
• Annual Failure = inability meet desired outcome

Question 3

AMALGAM

Answer 3

15yrs, 3% –> creep (corrodes+seals)
o ≠ cavity prep
o Handling
o ≠ condense
o Microleakage (creep)
o Tarnish+corrosion

Question 4

COMPOSITE

Answer 4

8yrs, 2% –> shrinkage↓, now low stress flowable mat
Technique Sensitive
o ≠ obtain long-term adhesion comp+d, fail gingival margin
o ≠ light cure increments
o Contamination = moisture control
o Shrinkage = caries, fracture, sens, marginal deficiency

Question 5

GLASS IONOMER

Answer 5

3-4yrs 7% alone –> lacks phys prop alone, ≠ strong occlusal forces
o good d replacement as lining/base
o poor handling

Question 6

WHY REPAIR VS REPLACE

Answer 6

minimally invasive technique > replacement, preserve healthy tooth tissue

Question 7

FEATURES OF REPAIR

Answer 7

• no spreading caries  would structurally undermine rest or remaining tooth
• sufficient vol retained rest  strong, resist masticatory forces
• can bond or mechanically interlock new rest into old+tooth
• no potential aesthetic mismatches
• adhesive rest, localised+accessible defect  remove overhang/discolour, surface recontour

Question 8

REPLACING W AMALGAM ISSUES

Answer 8

• amalgam needs 2mm depth+undercuts
• amalgam ≠ bond old

Question 9

FACTORS AFFECTING SUCCESS+FAILURE

Answer 9

patient, operative, material

Question 10

7 PATIENT FACTORS – educate to reduce risk (disease failure)

Answer 10

• Caries high risk = OH, diet, checkups
• Heavy occlusal forces – bruxism = tooth+rest wear, fracture, fail
• Anterior –> easier examine+visualise+detect
• Cavity size+location –> moisture control
• Pulpal problems
• Perio dis
• Allergy
  o Lichenoid reaction, amalgam/gold alloy
  –> diagnosis= replace, lesion resolve 2wk
  –> refer oral med, biopsy, topical steroid
  o HEMA sensitivity, resin comp/FS

Question 11

OPERATIVE

Answer 11

• Correct choice+handling mat
• Cavity design, retention, remove unsupported e + weakened cusps
• Technique placement+finishing

Question 12

MATERIAL (technical failure = tooth+rest fracture, marginal breakdown, retention fail)

Answer 12

• Compressive+flexural strength
• Rigidty (elasticity modulus)
• Surface hardness + wear
• Ability to seal+minimise microleakage –> cause 2° caries + failure
• Thermal expansion
• Adhesion property
• Solubility
• Creep

Question 13

ASSESS REST

Answer 13

• Aesthetics = marginal stain, lose marginal integrity,lose surface lustre+polish –> colour △
• Function = fracture+retention, wear, proximal atomical form
• Biology = recurrence caries/erosion/abfraction, integrity, oral/mucosa health

Question 14

CLINICALLY DETECT REST

Answer 14

• Pt symptoms = pain, discolouration, fracture
• Visual+tactile = caries, open contact, overhang
• Radiograph = caries, apical+perio status, overhang
• Occlusal exam = contact opposing structure, anatomy loss

Question 15

2° CARIES

Answer 15

• Radiograph confirm = margin, under rest, remain from initial rest, ↑risk comp
• Treat as new lesion, preventative measures
  –>operative