Evaluation of local and systemic application of melatonine on bone recovery after tooth extraction in bisphosphonate applied rats

Aim: The purpose of our study was to investigate the effects of systemic and local application of melatonine after tooth extraction in bisphosphonate applied rats, on the healing of extraction socket histopathologically and immunohistochemically. Materials and Method: 44 Wistar Albino rats were included in the study. Subjects were divided into 4 groups each consists of 11 rats. Control (C) group, Bisphosphonate (BİF) group, Bisphosphonate + Local Melatonine (BİF+LM) group and Bisphosphonate + Systemic Melatonine (BİF+SM) group. Zoledronic acid (0.4 mg/kg) was applied intraperitoneally once a week from the beginning of the experiment to all the groups except control group. On the 28th day of the experiment lower left first molar tooth were extracted in all subjects. Local (1.2 mg) and systemic melatonine (10 mg/kg) were applied immediately after tooth extraction. All subjects were sacrificed on the 56th day of the experiment. Left mandible of the subjects were removed and examined histopathologically. Data were evaluated statistically. Results: According to the results, epithelization in BİF+LM groups was significantly higher statistically than epithelization in BİF and BİF+SM groups (p=0.001, p=0.006, p<0.001, p<0.001). It was determined that, osteonecrosis values were significantly lower (p<0.001) than BİF groups in K, BİF+LM and BİF+SM groups and lower than K group in BİF+LM and BİF+SM groups respectively. İnflamation values were found significantly lower in K, BİF+LM and BİF+SM groups than BİF group (p<0.001, p=0.001, p=0.006). When examined immunohistochemically, osteocalsin values were significantly higher than BİF groups in K, BİF+LM and BİF+SM groups and higher than BİF + SM and K groups in BİF + LM groups statistically. (p<0.001, p<0.001, p=0.001, p=0.001, p=0.023). The levels of VEGF were determined to be significantly higher than BİF group in BİF+LM and BİF+SM groups statistically (p<0.001). Conclusions: After evaluating the histopathologic and immunohistochemical results, we concluded that the positive effect of melatonine application on bone recovery in all four groups was due to the anti-inflamatuary property of the agent, anjiyogenesis and increase in new bone formation capacity. Application of melatonine is considered to be a promising approach in the treatment and in preventing the formation of BRONJ.