A controlled clinical trial of implant-retained mandibular overdentures; five-years' results of clinical aspects and aftercare of IMZ implants and Branemark implants

The aim of this prospective randomized controlled clinical trial was to eva luate a set of clinical items and prosthetic aftercare of edentulous patien ts with a mandibular overdenture retained by 2 IMZ implants or 2 Branemark implants during a 5-years' period. Patients were allocated to the IMZ group (n=29) or the Branemark group (n=32) by a computerized balancing method. I n the IMZ group 4 implants were lost during the 5-years' follow-up (surviva l rate: 93%). In the Branemark group 9 implants were lost (survival rate: 8 6%). All patients were re-operated successfully. Multiple prosthetic revisi ons were necessary in both groups, especially the precision attachment syst em in the overdenture was subject to frequent fracture or loosening. From t his study can be concluded that there is no difference in clinical state, r adiographical state, survival rate and clinical implant performance between the IMZ implant system and the Branemark implant system supporting an over denture on 2 implants after 5 years of follow-up.