Acting of zoledronic acid and estrogen therapy on alveolar wound healing in ageing rats

• Grant number: 12/22766-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2013
• End date: November 30, 2014
• Field of knowledge: Biological Sciences - Physiology - Physiology of Organs and Systems
• Principal Investigator: Rita Cássia Menegati Dornelles
• Grantee: Gustavo Antonio Correa Momesso
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil

Abstract

The aging of the population increases the incidence of bone pathologies, such as cancer and osteoporosis. Zoledronic acid, third-generation bisphosphonates, has been currently used for the treatment of several diseases, like osteoporosis and metastatic lesions in bone. There has been an increase in reports of a serious side effect of these drugs: the bisphosphonate-related osteonecrosis of jaws. Studies conducted in our laboratory showed that hipoestrogenism (ovariectomized rats) and zoledronic helped in the delay of alveolar repair and favors the occurrence of necrotic areas in adult rats (06 months). Our hypothesis is that natural aging favors the formation of osteonecrosis of the jaw, after pulling out the first molar of senile rats treated with zoledronic acid, and that estradiol therapy reduces this action. Hence, the objective of this study is to evaluate the effect of zoledronic acid on alveolar bone repair in elderly Wistar rats which have or haven't gone through estrogen therapy. In this study, 18-month old rats will be used and they are going to get estradiol in for 90 days. Seven weeks prior to euthanasia, the rats will receive zoledronic acid once a week, for four weeks. After three weeks of treatment, the extraction of the first lower molar will happen. Four weeks after the extraction of the first lower molar and after the final application of zoledronic acid, euthanasia will be performed. Estradiol, calcium, phosphorus, and alkaline phosphatase, are to be counted through blood tests. Histologic and immunohistochemistry analysis will be conducted in the alveolar bone.(AU)