Long-term results of endosteal implants used for restoration of oral function after oncologic surgery.

The aim of the present study was to analyse the long-term survival rate of endosteal implants used for restoration of oral function in patients having undergone oncologic surgery. Eighty-three consecutive patients, who had received a total of 409 endosteal implants ad modum Brånemark, subsequent to resections of soft tissue and bone during ablation of oral malignancies, were enrolled into the study. A life-table analysis was used to determine the survival rate of the implants placed during a period of 13 years. Log rank tests and Cox regression analysis were employed to identify relevant effects of surgical parameters on implant survival. A total of 38 implant failures were encountered. Most of the losses (n=19) occurred during the first year of functional loading. Subsequent failures were evenly distributed across the remaining follow-up period. The cumulative overall survival rate of implants was 56.5%. Previous radiation therapy, insertion into grafted bone or original jaw bone and the technique of grafting did not significantly affect the survival rates. In the Cox regression analysis, the timing of implant placement in the group of patients with bone grafts (primary vs secondary placement) was significantly related to the survival rate (P=0.0197), with a lower survival rate of 36.2% for primary insertion of implants and 67.1% for secondary placement.