T1: Occlusion for Partial Dentures

Question 1

What is occlusion?

Answer 1

• static relationship between incising / masticating surfaces of maxillary/ mandibular teeth/ tooth analogues

Question 2

What is intercuspal position? ICP

Answer 2

• complete intercuspation of opposing teeth independant of condylar position, sometimes referred to as the best fir of teeth regardless of condylar position

Question 3

What is retruded contact position? RCP

Answer 3

• guided occlusal relationship occuring at the most retruded position of condyles in the joint cavities

Question 4

What are index teeth?

Answer 4

• contacting facets of teeth in intercuspal position

Question 5

ICP vs RCP

Answer 5

• where possible try to conform to existing occlusion

Question 6

Conforming or Changing occlusion

Answer 6

Conforming
- works best in a stable occlusion with sufficient index teeth
- ensure prosthesis doesn’t alter occlusion
- usually use ICP

Changing
- often occlusion is unstable and lack of sufficient index teeth
- often use RCP
- usually more challenging to record occlusion

Question 7

Articulated study casts

Answer 7

• record occlusion
• occasionally casts can be articulated together without need for any formal recording of occlusion
• more accurate articulation by obtaining an inter-occlusal record

Question 8

What to use for interocclusal record?

Answer 8

1. Bite registration paste - silicone paste
2. wax wafer - modelling wax
3. modified wax wafer - alminax

Question 9

if insuficient teeth, how to record occlusion?

Answer 9

• record blocks needed

Question 10

Types of record blocks?

Answer 10

• wax
• wire strengthener
• CoCr base
• Shellac base