8/20: Guiding Planes

Question 1

1. These are vertically parallel surfaces of abutment teeth oriented so as to contribute to the direction of the path of placement a d dislodgement of removable partial dentures

Answer 1

a. Guide planes

Question 2

2. How should the abutment teeth be oriented?

Answer 2

a. To contribute to the DIRECTION of the path of placement

Question 3

3. Do guide planes exist naturally?

Answer 3

a. Very rarely, so we have to create them

Question 4

4. What are the functions of the guiding planes?

Answer 4

a. Provide 1 path for placement
b. Ensure the intended actions of the RPD
c. Increase frictional components of minor connectors
d. Eliminate food traps
e. Lower HOC

Question 5

5. Should we reduce the large undercut to a smaller one near the surveying line?

Answer 5

Yes

Question 6

6. How do we reduce the undercut near the surveying line?

Answer 6

a. By tilting cast or grinding surface

Question 7

7. Where should the location of guiding planes be?

Answer 7

a. Proximal surfaces of abutment teeth
b. Parallel to long axis of the tooth
c. Increase length so we have more resistance

Question 8

8. As length of the guide plane is increased, what happens to the frictional and rotation resistance?

Answer 8

Increases

Question 9

9. How much width should you have in the guide plane?

Answer 9

a. As wide as the widest portion of the occlusal rest
b. 1⁄3 B-L width
c. 1⁄2 distance between cusp tips

Question 10

10. What length should the guide plane be for tooth supported abutment?

Answer 10

3-4mm

Question 11

11. What length should the guide plane be for tooth-tissue supported abutments (distal extension abutments)?

Answer 11

1.5-2mm