Evaluation of Peri-Implant Tissue in Patients Starting Antiresorptive Agent Treatment After Implant Placement: A Nested Case-Control Study

Background and Objectives: To evaluate the effect of antiresorptive agents (ARAs) on periimplant tissues and to examine risk factors for peri-implant medication-related osteonecrosis of the jaw (MRONJ). Materials and Methods: The study cohort consisted of patients who underwent implant surgery or maintenance treatment between March 2012 and December 2024. Patients were divided into two groups: those who used bisphosphonates (BPs) or denosumab (Dmab) to treat osteoporosis after implant treatment (ARA group) and a control group. Peri-implant clinical parameters (implant probing depth (iPPD) implant bleeding on probing (iBoP), marginal bone loss (MBL), and mandibular cortical index (MCI)) measured at baseline and at the final visit were statistically evaluated and compared in both groups. Risk factors were examined by multivariate analysis for adjusted odds ratios (aOR). Results: A total of 192 implants in 61 patients (52 female, 9 male) were included in this study. The ARA group consisted of 89 implants (22 patients). Comparison of clinical parameters showed that the ARA group had significantly higher maximum iPPD and iBoP variation over time than the control group. Risk factors for peri-implantitis as objective variables were the use of ARAs (aOR: 3.91, 95% confidence interval [CI] 1.29–11.9) and change in maximum iPPD over time (aOR: 1.86, 95% CI 0.754–4.58). Conclusions: During long-term implant maintenance treatment, patients' health and medication status change. Monitoring of peri-implantitis, the presumed cause of peri-implant MRONJ, is essential, especially in patients who started ARA treatment after implant placement, and special attention should be paid to changes in implant pocket depth.