Occlusion in RPD's

Question 1

Why is occlusion important in RPD’s?

Answer 1

If get it wrong the patient will not tolerate the denture no matter how well fits in the arch

Question 2

How are RPD’s different to CD’s

Answer 2

The patient has natural teeth remaining which will influence:
The occlusion
The position of teeth
The occlusal plane
This has significant impact on the denture construction process from planning/design through delivery of the denture

Question 3

What is ICP

Answer 3

The point of max intercuspation between the teeth - natural position

Question 4

When is ICP stable?

Answer 4

If goes in to the same position each time dictated by the cusp form

Question 5

When will you not have a stable ICP?

Answer 5

If grind teeth - have no cusps

Question 6

What is centric relation?

Answer 6

Relationship of the mandible to the maxilla when the condyles are seated in the midmost uppermost position of the glenoid fossa

Question 7

What does CR have nothing to do with?

Answer 7

CR has nothing to do with teeth, is a jaw relationship

Question 8

Why do dentists you CR position?

Answer 8

Useful as it is reproducible and generally well tolerated by patients

Question 9

What is the optimum position for neuromuscular system?

Answer 9

Centric relation

Question 10

What is retruded contact position related to?

What is it?

Answer 10

Teeth

The first tooth contact when the condyles are fully seated in the glenoid fossa

Question 11

Where is the usual first point of contact in CR?

Answer 11

Usually on a posterior tooth

Sometimes can have a couple of positions

Question 12

What is vertical dimension?

Answer 12

Indicates the superior-inferior relationship of the maxilla and the mandible when the teeth are situated in max intercuspation

Question 13

How does a stable ICP appear?

Answer 13

Clear intercuspation between numerous teeth which the patient consistently replicates

Question 14

When is it more difficult to get into stable ICP?

Answer 14

When have fewer teeth present or if have tooth wear

Reducing the cusp heigh then dont have the same interlocking and ICP isnt clear

Question 15

How to check is the ICP is stable?

Answer 15

Move the teeth laterally while in ICP

Question 16

When will vertical dimension not be stable?

Answer 16

If have no occluding contacts - if the teeth dont oppoer each other

Question 17

When may you need to increase the OVD?

Answer 17

IF posterior teeth over erupt - no longer have space to place opposing teeth

Question 18

If patient has a stable ICP and acceptable vertical dimension what stage can you now go on to for mucosa and tooth borne dentures?

Answer 18

Mucosa- proceed to making a mucosa borne denture - design with study models
Tooth borne - consideration to the position of the occlusal rests consider articulating the models prior to designing

Question 19

If patient has a unstable ICP and acceptable vertical dimension what stage can you now go on to for mucosa and tooth borne dentures?

Answer 19

Establish a new ICP to coincide with centric relation (as this is reproducible)W
Need to establish the new occlusal scheme on reg rims and articulate the models prior to designing

Question 20

If patient has a stable ICP and unacceptable vertical dimension what stage can you now go on to for mucosa and tooth borne dentures?

Answer 20

Will need to use reg rims to establish a new ICP at the correct vertical dimension to be coincident with centric relation

Question 21

If patient has no stable ICP and unacceptable vertical dimension what stage can you now go on to for mucosa and tooth borne dentures?

Answer 21

Need to use reg rims to establish a new ICP at the correct vertical dimension to be coincident to centric relation

Question 22

When do you design the denture?

Answer 22

After primary imps or after articulated

Question 23

What is needed to design the partial denture?

Answer 23

Surveyed and articulated study casts

Once designed the denture you can proceed to tooth prep and secondary imps

Question 24

What should the rests seats ideally be like?

Answer 24

1mm deep, not into dentine with rounded edges
Dont forget to leave enough space for the minor connector or clasp arm
There needs to be enough space for the rest seats without it affecting the occlusion

Question 25

What happens at the CoCr try-in stage?

Answer 25

Check the framework fits well on the cast and is fully seated
Then transfer to the mouth and ensure that the framework fully seats - paying particular attention to the rest seats
Check the occlusion
If required adjust until framework seats fully and doesn’t interfere with the occlusion

Question 26

What is done at wax reg?

Answer 26

This will be on a wax/shellac/acrylic base for acryic dentures
This should be on the metal framework for the cobalt chrome denture

Question 27

What does the wax reg stage confirm?

Answer 27

occlusal relationship, tooth position and incisal plane

Question 28

What is done at fit?

Answer 28

Check there have been no changes to the occlusion from the wax try in stage
May any adjustments
Check record - double check occlusion

Question 29

What is done at the review?

Answer 29

Make sure no changes and that patient is happy

Question 30

When use metal backings?

Answer 30

Gives protection to anterior teeth, good for bruxists and heavy bite
Need to know the exact position of the teeth prior to the metal framework being made
Done after wax reg

Question 31

What is the summary of the denture construction process

Answer 31

Primary imps
Wax reg- of occlusion not obvious
Tooth try-in - if metal backings required 
Design denture
Tooth prep and secondary imps
Framework try-in for CoCr 
Wax reg on CoCr
Wax try in
Re-try
Fit
Review