A prospective 5-year study of two cast framework alloys for fixed implant-supported mandibular prostheses.

Purpose: A longitudinal 5-year clinical investigation was carried out to compare screw-retained frameworks constructed from two alloys with different mechanical properties, either gold or silver-palladium, supported in the mandible by the Astra Tech implant system.

Materials And Methods: Twenty-six edentulous patients with mandibular implants were divided into two groups: group A was provided with Chicago IV gold alloy superstructures, and group B was provided with Palliag M silver-palladium alloy superstructures. The surgical procedures for placing the mandibular bone implants and the prosthodontic and laboratory techniques for constructing the prostheses were carried out according to standard, well-documented practices.