2. INTRODUCTION
Maxfield stated, “ Common observation clearly
indicates that the ability of living things to
tolerate force is largely dependent upon the
magnitude or intensity of the force”
Dentist must consider direction, duration and
frequency of force application, as well as the
magnitude of the force
www.asiandentalacademy.org
5. CANTILEVER
It is beam supported only at one
end can act as a first – class
lever
www.asiandentalacademy.org
6. Location of stabilizing and retentive components in relation to
the horizontal axis of rotation of the abutment becomes
extremely important
www.asiandentalacademy.org
7. The axial surface contours of abutment teeth must be altered to
locate components of direct retainer assemblies more favorably in
relation to the abutment’s horizontal axis
www.asiandentalacademy.org
9. POSSIBLE MOVEMENTS OF
PARTIAL DENTURE
One movement is rotation about an axis
through the most posterior abutments
A second movement is rotation about a
longitudinal axis as the distal extension base
– moves in a rotary direction about the
residual ridge
A third movement is rotation about an
imaginary vertical axis located near the
center of the dental arch
www.asiandentalacademy.org
13. “The component of a removable partial denture
that assists the direct retainer(s) in preventing
displacement of the distal extension denture
base by functioning through lever action on
the opposite side of the fulcrum line when the
denture base moves away from the tissues in
pure rotation around the fulcrum line.”-GPT
INDIRECT RETAINER
www.asiandentalacademy.org
14. An indirect retainer does not control the movement of
the denture base in the tissueward direction
Amount of movement =amount of compressible
mucosa
Fulcrum line runs between the most posterior rests.
www.asiandentalacademy.org
15. Movement away from ridge
Sticky foods
Functions of tissues at the borders
Gravity (maxillary denture)
Fulcrum line runs through retentive tip of direct retainer
www.asiandentalacademy.org
18. Comparision of Tooth -supported
and Tissue-supported partial
dentures
www.asiandentalacademy.org
19. REFERENCES
A.A.Grant and W.Johnson,Removable denture Prosthodontics,
ed 2.1992,Churchill livingstone Inc.
Ernest L.Miller and Joseph E.Grasso,Removable Partial
Prosthodontics, ed 2. 1979,Williams and Willkins.
Glen P. Mcgivney, Alan B. Carr.Mccraken’s Removable Partial
Prosthodontics, ed10. St. Louis ;2000 ,The C.V. Mosby Co.
Stewart ,Rudd and Keubker, Clinical Removable Partial
Prosthodontics,ed 2.1997,Ishiyaku EuroAmerica Inc. U.S.A
William E. Avant.Indirect retention In partial denture Design.J
Prosthet Dent.16:1103-1110
www.asiandentalacademy.org