DENTAL IMPLANTS FOLLOWING RADICAL ORAL-CANCER SURGERY AND ADJUVANT RADIOTHERAPY

Following radical oral cancer surgery and postoperative adjuvant radio therapy with a total dose of GO Gy, 71 IMZ and 150 Branemark implants were placed in the mandibles and 28 Branemark implants were placed in the maxillas of 60 patients between 1985 and 1995. Adjunctive hyperbar ic oxygen therapy was not used. Osteoradionecrosis of the mandible occ urred in two patients (3.4%), and necrosis of soft tissue in the floor of the mouth region occurred in three patients (5.2%). Twenty-one imp lants (18 in the mandible and 2 in the maxilla) were not osseointegrat ed when surgically exposed. In subsequent follow-up, 17 mandibular imp lants and 5 maxillary implants lost their osseointegration. The life t able method indicated that 5-year actuarial implant success rates in t he irradiated mandible were 77.5% for the IMZ system and 83.6% for the Branemark system. These differences were not statistically significan t. Retrospective analysis indicated that the success of implants in th e irradiated mandible is determined after an interval of 18 to 24 mont hs. For a small number of Branemark implants in the irradiated maxilla , an actuarial success rate of 85.5% was found.