Guiding Planes

Question 1

Guiding Planes

Answer 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

Question 2

Do flat
surfaces exist
on natural
teeth??

Answer 2

Guiding Planes Rarely Exist
Naturally
Guiding Planes Must Be Created

Question 3

skipped
Functions of Guiding
Planes: (5)

Answer 3

• Provide for one path of placement/removal
• Ensure the intended actions of the RPD
components*
• Eliminate/decrease gross food traps**
• Increase frictional component of minor
connectors
• Lowers the height of
contour on proximal
surfaces to allow better
positioning of arms

Question 4

Guiding Plane
The large undercut
adjacent to the
proximal surface
should be

Answer 4

reduced in size.

Question 5

Guiding Plane
The reduction can
be accomplished
by (2)

Answer 5

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

Question 6

Guiding Plane
Most often,
using selective
grinding,

Answer 6

the
undercut is
reduced and a
guiding plane is
prepared.

Question 7

Location of Guiding
Planes: (2)

Answer 7

• Proximal surfaces of abutment teeth
• Parallel to long axis of teeth, if
possible

Question 8

As length is increased, frictional
retention is — and resistance
to rotation is —

Answer 8

increased
increased

Question 9

Width of Guiding
Planes: (3)

Answer 9

• As wide as the widest portion of the
occlusal rest
• One-third the bucco-lingual width of
the tooth
• One-half the distance between the
cusp tips

Question 10

Tooth supported abutments

Answer 10

3.0 to 4.0 mm

Question 11

ooth-tissue supported abutments (distal
extension abutments)

Answer 11

1.5 to 2.0 mm