A study of peri-implant tissue clinical parameters in patients starting anti-osteoporosis medication after existing implant function: a prospective cohort study

Purpose Recently, rare cases of medication-related peri-implant osteonecrosis of the jaw (PI-MRONJ) have been reported. In patients with functional implants who begin using anti-osteoporosis medications (AOMs) after implantation, PI-MRONJ is unpredictable and poses a significant threat to the patient. In this study, we aimed to evaluate the impact of AOMs on peri-implant tissues and to examine risk factors for peri-implantitis, a presumed trigger for PI-MRONJ. Methods The study cohort consisted of patients who underwent implant maintenance treatment between January 2016 and February 2024. Patients were divided into AOM users (AOM group) and controls (control group). Clinical parameters were statistically evaluated, including implant probing depth (iPPD), implant bleeding on probing (iBoP), marginal bone resorption (MBL), and mandibular cortical index (MCI) measured at baseline and at the last visit. Risk factors were examined by multivariate analysis for adjusted odds ratios. Results A total of 94 patients (35 male, 59 female) with 270 implants were recruited. The AOM group had 93 implants (24 patients). Comparison of clinical parameters showed significantly greater changes in iBoP ( p = 0.000768) and MBL ( p = 0.000863) scores over time in the AOM group than in the control group. Risk factors for peri-implantitis were a history of moderate or severe periodontal disease (OR: 15.8, 95% CI 3.6–69.3, p = 0.000256) and MCI class 3 (OR: 3.3, 95% CI 1.4–7.8, p = 0.00534). Conclusions In implant treatment of AOM users, special attention should be paid to local inflammation, which is presumed to be the cause of PI-MRONJ. Graphical Abstract