Comparative stress analyses of fixed free-end osseointegrated prostheses using the finite element method.

We investigated the designs of osseointegrated prostheses in cases of free-end partial edentulism using comparative stress analyses interpreted with the two-dimensional finite element method. Seven free-end fixed osseointegrated prosthesis models with various connection designs (i.e., rigidly connected to an abutment tooth, not connected to an abutment tooth, connected to an abutment tooth with a non-rigid attachment) were studied. The stress values of the seven models loaded with vertical force were analyzed. When the prosthesis was not connected to natural abutment tooth but was supported instead by two free-standing implant abutments, lowest levels of stress in bone were noted. On the other hand, non-rigid attachments, when incorporated into a prosthesis, did not significantly reduce the level of stress in bone.