Five-year statistical and clinical observations with the IMZ two-stage osteointegrated implant system.

This study evaluated patients who were reconstructed with the IMZ system, which consists of a cylindrical implant with an intramobile element for stress relief. It is placed through a two-stage surgical procedure resulting in osteointegration. During a 5-year period, 1,059 implants were placed in 322 patients. Twenty-one implants were lost to follow-up. A total of 28 implants failed over the 5-year period, of which 9 had not integrated at stage 2 surgery. Of the remaining implants, 19 failed primarily for periodontal and prosthetic reasons. The life table method was used for statistical analysis. The 5-year survival rate of all IMZ implants was 95%. Seventy-five percent of the implants were placed to restore partial edentulism, with a survival rate of 96%. The survival rate for totally edentulous patients was also 96%. Forty-four percent of the implants were placed in the maxilla, with a survival rate of 92%. The survival rate in the mandible was 99%. Sixty-six percent of the implants were placed in women, with a survival rate of 94%. The survival rate in men was 98%. Major factors that positively influenced long-term survival were use of the longest and largest-diameter implants appropriate for the clinical situation.