Stress Distribution in an Implant-Supported Mandibular Complete Denture Using Different Cantilever Lengths and Occlusal Coating Materials.

PURPOSE: The aim of this study was to assess stress distribution in the bone-implant interface of a mandibular implant-supported prosthesis with different cantilever lengths, aesthetic coating materials, and implant abutments.

MATERIALS AND METHODS: A photoelastic model of an edentulous mandible, containing 5 external hexagon implants, was constructed. Experimental models were divided into 6 groups: group 1-UCLA component and metal bar; group 2-UCLA component and acrylic resin coating; group 3-UCLA component and porcelain coating; group 4-abutment and metal bar; group 5-abutment and acrylic resin coating; and group 6-abutment and porcelain coating. Forces were applied to the most anterior implant, the most posterior implant, and different cantilever lengths.

RESULTS: The results showed a higher number of high-stress fringes as the cantilever length increased. Fringes were better distributed in groups with prostheses composed of acrylic resin and in groups that contained an abutment.

CONCLUSION: The stress distribution in the bone-implant interface is improved when the cantilever is eliminated and when abutments in an acrylic resin prosthesis are used.