Life Table Analysis and Clinical Evaluation of Oral Implants Supporting Prostheses After Resection of Malignant Tumors

Seventeen mostly elderly patients, 13 men and 4 women, were consecutively admitted for implant-prosthodontic treatment after they had undergone resection of malignant tumors in the oral cavity. A total of 53 dental implants (ITI-Straumann) was placed, 12 in the maxilla, 41 in the mandible. The prosthetic rehabilitation consisted of overdenture therapy in 15 patients, and 2 patients were treated with fixed partial prostheses. Thirty-three implants were prescribed for patients who received radiotherapy either before or after implant placement. The average dose varied between 50 and 74 Gy. Eighteen implants were located in grafted bone from the fibula, scapula, or hip. For 2 patients, hyperbaric oxygen therapy was also prescribed after osteoradionecrosis had developed. One implant was lost before prosthetic loading. During an observation period of up to 7 years after loading, 3 more implants were removed. All implant losses occurred in the mandibles of patients who had received radiotherapy. A life table analysis was performed, and the cumulative survival rates, calculated for 2, 3, and 5 years, were 93%, 90%, and 90%, respectively. No failures or complications were observed with technical components of the implants or prostheses. All prostheses could be maintained during the entire observation time. Although in the present investigation the survival rate of implants was slightly lower than under standard conditions, the treatment with implant-supported prostheses seemed to be advantageous for patients who had undergone intraoral resections. Keywords: implant prosthesis, irradiated bone, life table analysis, malignant tumors, oral implants