guiding planes

Question 1

do guiding planes exist naturally?

Answer 1

rarely
they must be created

Question 1

vertically parallel surfaces of abutment teeth oriented so as to contribute to the DIRECTION of the path of placement and dislodgement of removable partial dentures

Answer 1

guiding planes

Question 2

5 functions of guiding planes

Answer 2

1. provides for one path of placement/removal
2. ensure the intended actions of the RPD components
3. eliminates/decreases gross food traps
4. increase frictional component of minor connectors
5. lowers height of contour on proximal surfaces to allow better positioning of arms

Question 3

how can the reduction of guiding planes be accomplished

Answer 3

by altering the tilt of the cast or by selective grinding of enamel surface

Question 4

the undercut is reduced and guiding plane is prepared by what most used method

Answer 4

selective grinding

Question 5

location of guiding planes

Answer 5

1. proximal surfaces of abutment teeth
2. parallel to long axis of teeth, if possible

Question 6

with guiding planes, as length is increased, frictional retention is (increased/decreased) and resistance to rotation is (increased/decreased)

Answer 6

increased
increased

Question 7

width of guiding planes

Answer 7

as wide as the widest portion of the occlusal rest

1/3 bucco-lingual width of tooth
1/2 distance between cusp tips

Question 8

Length of guiding planes
tooth support abutments:

tooth tissue supported abutments (distal extension abutments):

Answer 8

tooth support abutments length: 3-4mm
tooth tissue supported abutments (distal extension abutments) length: 1.5-2mm