Long-Term Results of Endosteal Implants Following Radical Oral Cancer Surgery with and without Adjuvant Radiation Therapy

Purpose: The aim of this study was to analyze the long-term survival of implants and implant-retained prostheses in patients after ablative surgery of oral cancer with or without adjunctive radiation therapy. Materials and Methods: Between 1997 and 2008, 66 patients who had undergone ablative tumor surgery in the oral cavity were treated with dental implants (n = 262). Thirty-four patients received radiation therapy in daily fractions of 2 Gy administered on 18 to 30 days. Implants were inserted in the maxilla (49; 18.7%) or mandible (213; 81.3%), in nonirradiated residual (65; 24.8%) or grafted bone (44; 16.8%) and in irradiated residual (15.6%) or grafted bone (39; 14.9%). Seventeen fixed protheses and 53 removable dentures (34 bar attachments, 9 telescopic and 10 ball retained dentures) were inserted. Results: Mean follow- up after implant insertion was 47.99 (+/- 34.31) months (range 12- 140 months). The overall 1-, 5-, and 10- year survival rates of all implants were 96.6%, 96.6%, and 86.9%, respectively. Fourteen implants were lost in nine patients (5.3% of all implants); eight implants were primary losses, and five secondary losses because of an operation of tumor recurrence. There was no significantly lower implant survival for implants inserted into irradiated bone (p =.302), bone and/ or soft- tissue grafts (p =.436), and maxilla or mandible (p =.563). All prosthetic restorations in patients without tumor recurrence could be maintained during the observation period. Conclusions: Implant survival is not significantly influenced by radiation therapy, grafts (bone and/or soft tissue), or location (maxilla or mandible). However, implants placed in irradiated bone exhibit a higher failure rate during the healing period than those placed in non- irradiated bone. No superstructure was particularly favorable. Osseointegrated implants can be used successfully in patients with prior history of ablative surgery with and without additional radiation therapy.