Timing for implant placement in patients treated with radiotherapy of head and neck

Aim of this retrospective study was to evaluate the most appropriate timing for the implant placement in oral cancer patients treated with radiation therapy.

We collected data for 17 subjects (10 females, 7 males; mean age: 51 ± 19) with malignant oral tumors who had been treated with ablative surgery and radiation therapy of head and neck. The radiotherapy was set in accordance with the NCCN guidelines. Every patient received dental implant rehabilitation between 2014 and 2016. A total of 84 titanium implants were placed, at a minimum interval of 12 months, in irradiated residual bone. Every patient underwent a minimum follow-up of 12 months.

Implant loss was dependent on the position and location of the implants (P = 0.05-0.1). Moreover, implant survival was dependent on the total dose of radiation and, mostly, on the timing of implant insertion after the end of the radiation therapy. This result was highly statistically significant (P < 0.01). Whether the implant was loaded is another highly significant (P < 0.01) factor determining survival. We observed significantly better outcomes when the implant was placed at least after 14 months and not loaded until at least 6 months after placement.

Although the retrospective design of this study could be affected by selection and information biases, we conclude that a delayed implant placement after the end of the radiation therapy and a delayed loading protocol will give the best chance of implant osseointegration, stability and, ultimately, effective dental rehabilitation.