Evaluation of platelet-rich fibrin and adjuvant therapies in the treatment of induced osteonecrosis of the jaws in senile rats

Abstract

Drug-related osteonecrosis of the jaw (MRONJ) is an adverse effect caused by the use of antiresorptive or antiangiogenic drugs. Its etiopathology, as well as its prevention, control, and cure, remain a challenge today. Local therapies play a key role in controlling these cases, such as ozone therapy administered in an oil vehicle. In addition, plasma concentrates have been widely used in dentistry due to their optimizing properties in soft tissue repair due to the expressive increase in the contribution of growth factors promoting neovascularization. Joining these two points, the objective of this work will be to evaluate the potential of L-PRF matrices in the control or even cure of MRONJ compared to local therapy with ozone in an oil vehicle. For that, 46 female Wistar rats, 18 months old, 15 of which will undergo bone tissue characterization, 3 will be blood donors for L-PRF and the others will be divided into 4 experimental groups (n=7): SAL group, where the rats will be submitted to applications of 0.9% sodium chloride solution and the ZOL group will receive an application of 100¼g/kg zoledronate, both every 3 days for 7 weeks; group ZOL+L-PRF and ZOL+OZN600 where the rats will receive the application of zoledronate in the same protocol and respectively: apposition of a matrix of L-PRF and the local application of ozonized sunflower oil 30ml - 600 mEq/kg in the concentration of 0.3 mg/kg for 2 minutes; both will receive local therapy in the periods of 0, 2 and 4 days after the extraction of the first lower left molar. Euthanasia will be performed 28 days after the extraction. The mandibles will be resected, reduced, and prepared for micro-CT, histological and immunohistochemical analysis (TNF-±, IL-1 ², VEGF, OCN, and TRAP), in addition, clinical analyzes will be performed with photographic documentation from the alveolus to the end of the experimental time. The data will be submitted to the normality curve to determine the most appropriate test (p<0.05).