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 us ed to evaluate the stress of mandibular posterior cantilevers for comp romised periodontal involved distal terminal abutments. Some commonly practiced methods to alleviate the stress from mastication of the cant ilever FPDs were also evaluated. From the analysis the following was c oncluded: (1) The most distal terminal abutment of a cantilever FPD ge nerally experienced a high stress concentration. (2) The cantilever FP Ds require at least two abutments. Optimum stress reduction occurred w ith a splinting of three abutments. To increase the number of abutment s to more than three, would not result in a proportional and meaningfu l reduction of stress in the periodontium. (3) To alter the bridge mat erial with more rigid material or to have a longer marginal preparatio n of the terminal abutment are ineffective for better stress distribut ion.