14. Occlusion and Restoration

Question 1

What tooth features must you understand the anatomy of for restoring?

Answer 1

• functional cusps (centric/supporting)
• non-functional cusps (non-centric/shearing)
• marginal ridges
• fossa pattern

Question 2

Functional cusps occlude with …
What are they on upper and lower jaw?

Answer 2

opposing central fossa
- palatal on upper
- buccal on lower

Question 3

Role of functional cusps

Answer 3

ensure adequate vertical dimension is maintained

Question 4

Non-functional cusps are … in upper and … in lower

Answer 4

• buccal
• lingual

Question 5

Role of non-functional cusps

Answer 5

• maintains food bolus on occlusal table
• maintains a certain stability around ICP

Question 6

Role of marginal ridges

Answer 6

• structural integrity and stability
• maintains deflection of food away from contact point
• mesial and distal fossa couldn’t be present without

Question 7

Why do we need to reproduce the morphology of teeth in restorations?

Answer 7

• provides a more stable system of cusps and fossa contact
• can be less detailed in a posterior worn occlusion but good to recreate the before

Question 8

An amalgam restoration is failing and you can see fractures through amalgam and tooth tissue. What is the following thought process?

Answer 8

• can be worth shortening the opposing cusp so in excursion the restorative interface isn’t overloaded
• mark up ICP and excursions - may see heavy interferance on NWS rubbing on the amalgam
• can look at shortening the opposing cusp and building up restoration to the shortened cusp
• due to less intense interdigitation of cusps, disclusion in lateral excursions

Question 9

In all senses of restoration, we try to do 2 things which are …

Answer 9

• build in predictability
• reduce failure

Question 10

Signs of occlusal instability

Answer 10

• fremitus
• drifting, rotation, over-eruption
• localised faceting/fractures
• loss of restorations
• loss of restorations
• abfraction
• vertical bony defects
• pain (tooth or TMD)

Question 11

What is fremitus?

Answer 11

• palpable vibration or displacement
• when teeth come into contact

Question 12

Why do we not leave restorations out of occlusion?

Answer 12

• over-eruption or drifting of restored tooth
• can cause premature contacts causing interferance and deflections at a later date
• need to conform to occlusion in ICP and excursions using articulating paper