A new innovative framework design for implant supported partial dentures

Objectives: To evaluate a new innovative framework design for mandibular Kennedy I partial dentures supported by distal implants. Methods: Twenty-four participants were selected with an edentulous maxilla and a partially dentate mandible with 6-8 remaining anterior teeth. A control group wore a Kennedy I conventional mandibular partial denture opposing a complete maxillary denture. Diagnostic mandibular partial denture frameworks were fabricated in a conventional manner for the control group ; but with a modified innovative V-shaped design for a test group. The test group subsequently had bilateral distal implants placed in mandible. The test group successively evaluated two different mandibular removable partial denture designs; one with healing abutments only ; the other with retentive anchors on the implants and gold matrices underneath the denture. The innovative V-shaped designs were made to match the dimensions of surgical stents for implant surgery. Reline procedures for the test group then allowed processed acrylic alone or gold matrix inclusion. Two extra cobalt-chromium frameworks were made from a mould of one of the participants, and processed to completion with clear acrylic and then evaluated under polarized light. Results: It was necessary to reduce the V-shaped framework to accommodate final implant positions, tissue conditioning procedures and reline impressions. Two-thirds of the frameworks of the test group participants had the mesh area of chrome-cobalt framework shortened. Weakness of the surrounding denture acrylic resulted with stress fractures. Where the occlusal plane was close to the ridge, and the acrylic was thin, there tended to be a fracture line before the last artificial tooth before relining for matrix inclusion.

Conclusion: The innovate framework design was unsuccessful there is a need to evaluate further designs of frameworks to avoid prosthodontic complications.

Supported by the ITI Research Foundation, Switzerland.