Systemic Ozone Therapy Improves Oral Hard and Soft Tissue Healing in Medication-Related Osteonecrosis of the Jaw (MRONJ): A Study in Senescent Female Rats

Background/Objectives: Medication-related osteonecrosis of the jaw (MRONJ) is a challenging condition often associated with bisphosphonate use, leading to impaired bone healing and difficult clinical management. Given the lack of predictable therapeutic options, this study investigated the effects of systemic ozone therapy on MRONJ healing. This study aimed to analyze the effects of systemic ozone therapy on oral hard and soft tissue healing in senescent rats with medication-related osteonecrosis of the jaw (MRONJ) induced by antiresorptive therapy. Methods: Twenty-eight senescent Wistar rats, aged eighteen months and weighing ~350 g, were used for this study. The animals were divided into four groups. The negative control (SAL) group received saline applications, while the control-treated (SAL+OZ) group received saline applications and ozone therapy (0.7 mg/kg). The MRONJ (ZOL) group received Zoledronate, an intravenous antiresorptive drug (100 μg/kg), and the MRONJ-treated (ZOL+OZ) group received zoledronate application and was treated with systemic ozone therapy (0.7 mg/kg). All rats underwent molar extraction in the third week of the experiment and were euthanized in the seventh week of the experiment. The mandibles were resected, reduced, and prepared for microtomographic analysis, histopathological/histometric analysis, and immunohistochemistry. Results: The ZOL group presented characteristics of vitreous, non-vital, and dense bone, poor vascularization, and high values of inflammation markers compatible with MRONJ. In contrast, the ZOL+OZ group exhibited improvement in alveolar bone and soft tissue healing, a decrease in nonvital bone area, and modulation of local inflammation. Conclusions: It can be concluded that Ozone therapy improved oral hard and soft tissue healing of MRONJ in senescent female rats subjected to antiresorptive drugs and might be considered for future clinical applications.