A controlled clinical trial of implant-retained mandibular overdentures: clinical aspects.

In a controlled clinical trial, treatment effects of mandibular overdentures on two different implant-systems in edentulous patients were compared one year after insertion of the new dentures. The implant-systems used were the Brånemark system (Brå) and the IMZ-system. Treatment was randomly assigned to 60 patients according to a balanced allocation method. Evaluation included peri-implant and radiographical parameters. According to the Delphi method a clinical implant performance scale (CIP) was constructed based on all conceivable complications of the different implant systems. During the osseointegration period, five Brå- and one IMZ-implants were lost. The results of one of the peri-implant parameters and the radiographical score showed significant differences considering the (pseudo) pocket probing depth (Brå better than IMZ, P < 0.001) and the radiographic-score (IMZ better than Brå, P < 0.003). The results for the CIP-scale were less favourable for the Brå-group than for the IMZ-group; however, these differences were not significant.