Methods to improve a periodontally involved terminal abutment of a cantilever fixed partial denture--a finite element stress analysis.

The two-dimensional plane stress finite element stress analysis was used to evaluate the stress of mandibular posterior cantilevers for compromised periodontal involved distal terminal abutments. Some commonly practiced methods to alleviate the stress from mastication of the cantilever FPDs were also evaluated. From the analysis the following was concluded: (1) The most distal terminal abutment of a cantilever FPD generally experienced a high stress concentration. (2) The cantilever FPDs require at least two abutments. Optimum stress reduction occurred with a splinting of three abutments. To increase the number of abutments to more than three, would not result in a proportional and meaningful reduction of stress in the periodontium. (3) To alter the bridge material with more rigid material or to have a longer marginal preparation of the terminal abutment are ineffective for better stress distribution.