In vivo Assessment of Occlusal Stress Distribution in Free-end Saddle Removable Partial Dentures. Part 1. Stress Distribution in Various Removable Partial Dentures.

Free-end saddle removable partial denture is an alternative to prevailing implant prostheses to restore the lost occlusal function. Occlusal stress distribution in free-end saddle RPD has been discussed by many prosthodontists. This problem of stress distribution must be recognized because of further application of free-end saddle RPD, realizing the limitation of its use. In this study, stress distribution in both abutment teeth and residual ridges were measured, analyzed, and discussed.The results were as follows:1. Selection of retainers influenced the occlusal force distribution even in the same free-end saddle condition.2. Occlusal force distribution in the free-end saddle was closely related to the connecting rigidity of the selected retainer. The higher the connecting rigidity was, the less the denture sharing load was.3. Abutment tooth mobility did not show any difference among the three different retainers assessed.4. Mucosal support was suggested to be important for sharing the occlusal force applied in even the rigid telescope retainer under various conditions.