Biomechanical considerations in removable partial denture design

3,109 views

Published on

Removable Prosthodontics

Published in: Health & Medicine, Technology
0 Comments
14 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
3,109
On SlideShare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
322
Comments
0
Likes
14
Embeds 0
No embeds

No notes for slide

Biomechanical considerations in removable partial denture design

  1. 1. BIOMECHANICAL CONSIDERATIONS IN REMOVABLE PARTIAL DENTURE DESIGN Presented by: Pooja Chaturvedi
  2. 2.  The ability of living things to tolerate force is largely dependent upon the magnitude or intensity of the force.  The control of potentially damaging forces is the primary goal of removable partial denture design.  It is the bone that provides support for a removable partial denture(i.e., the alveolar bone by way of periodontal ligament and the residual ridge bone through its soft tissues)  If potentially destructive forces can be minimized then the physiologic tolerance of the supporting structures are not exceeded and pathologic changes do not occur.
  3. 3. Principles Of Lever  When subjected to intraoral forces, a removable partial denture can perform the actions of lever.  A lever consists of a rigid bar, a fulcrum, an object to be moved and an applied force.  There are 3 classes of lever:
  4. 4. Most efficient type First class lever
  5. 5. Less efficient Second class lever
  6. 6. Least efficient Third class lever
  7. 7. As a rule, the longer the extension base, the greater the potential for damaging loads to be generated on the opposite side of the fulcrum line L E
  8. 8. Entirely Tooth Supported Prosthesis As the teeth occlude, the teeth are subjected primarily to axial loading. Support is gained entirely from the periodontal ligaments of indivisual teeth. Like a conventional fixed partial denture, a class III RPD is entirely tooth supported. As a result, forces are directed within the long axes of the abutments and are transmitted to the associated periodontal tissues.
  9. 9. Compared with an FPD, an RPD does not connect its abutments as rigidly to one another. Therefore limited movement is possible, and this movement can result in non-axial loading of the abutment teeth during function.
  10. 10. Combined Tooth-Tissue- Supported Prosthesis Classes I, II and IV They are not completely tooth supported but derive a varying degree of support from the tissues of the residual ridge.
  11. 11. De van determined that the mucoperiosteum of the residual ridge offers only 0.4% of the support provided by the periodontal ligament, i.e, the soft tissues are 250 times more diplaceable than the adjacent teeth.
  12. 12. Although initial forces may be oriented in the long axes of the abutments, differences in the tooth and soft tissue support eventually result in non-axial loading. This occurs as the prosthesis pivots on the abutment closest to the extension base. This can result in potentially damaging forces to the teeth and tissues anterior to the posterior abutment teeth.
  13. 13. Therefore these forces must be controlled through optimal tissue health, maximum coverage of soft tissues, proper use of direct retainers and placement of all components in their most advantageous position.

×