Oral implant survival in patients with bisphosphonate (BP)/antiresorptive and radiation therapy and their impact on osteonecrosis of the jaws. A systematic review

Aim: In this systematic review, we aimed to assess the impact of endosseous implants on the formation of an osteonecrosis of the jaw, as well as implant survival rates for patients under bisphosphonate (BP), antiresorptive and radiation therapy. Materials and methods: An electronic search was performed using PubMed, Embase, and Medline databases with the logical operators: "dental implant", "antiresorptive", "bisphosphonate", "irradiation", "radiotherapy", "radiation", "necrosis" and "survival". The search was limited to articles published up to 15 December 2016. Recent publications were also searched manually to find any relevant studies that might have been missed using the search criteria noted above. The outcome variables were the implant survival rate and the frequency of osteonecrosis of the jaws. Results: In total, 18 studies addressing oral implants in patients with BP or antiresorptive therapy and 23 with radiation therapy met the inclusion criteria and were included in this systematic review. Most of the studies had a retrospective design with a level of evidence (LoE) of III (moderately high risk of bias). Implant survival rate ranged from 92.86% to 100% in patients with BP/antiresorptive therapy (all due to osteoporosis) and 38.5% to 97.9% in patients with radiation therapy. For BP patients, osteonecrosis in relation to oral implants more frequently occurred in patients taking BPs due to malignant diseases. In patients with radiation therapy, an "implant triggered" necrosis is also a potential complication. The lack of data in the current literature concerning this issue does not allow a proper risk assessment to date. Conclusions: Within the limits of this systematic review, implant treatment concepts seem to be a valuable approach in patients with radiation therapy and patients with BP therapy due to an osteoporosis. In patients taking BPs due to a malignant disease, implant treatments are not recommended due to the high number of reported implant-related necrosis in this patient cohort. Outcomes of this review should, however, be regarded with caution due to the low level of evidence of the currently existing data. Keywords: bisphosphonates, dental implant, implant loss, implant survival, implant success, irradiation, necrosis of the jaw, osteonecrosis, radiation therapy, radiotherapy systematic review