Site‐specific radiation dosage and implant survival in oral cancer patients: A cohort study

Abstract

AbstractObjectivesWe assessed the radiation dosages (Dmean) on implant regions to identify the threshold for implant loss in patients with an intraoral malignancy treated with dental implants to support a mandibular denture during ablative surgery before volumetric‐modulated arc therapy (VMAT).Materials and MethodsData was collected prospectively from 28 patients treated surgically for an intraoral malignancy, followed by postoperative radiotherapy (VMAT) and analyzed retrospectively. Patients received 2 implants in the native mandible during ablative surgery. Implant‐specific Dmean values were retrieved from the patients' files. Radiographic bone loss was measured 1 year after implant placement and during the last follow‐up appointment. Implant survival was analyzed with the Kaplan–Meier method. Univariate logistic regression and Cox‐regression analyses were performed to investigate the effect of increasing implant‐specific radiation dosages on implant loss.ResultsFive out of 56 placed implants were lost during follow‐up (median 36.0 months, IQR 39.0). Radiographically, peri‐implant bone loss occurred in implants with a Dmean > 40 Gy. Implant loss occurred only in implants with a Dmean > 50 Gy.ConclusionAn implant‐specific Dmean higher than 50 Gy is related to more peri‐implant bone loss and, eventually, implant loss.