Repair of post-extraction sockets of aged rats incisors under therapy with intravenous bisphosphonate: microarquitecture and collagenous matrix analysis

• Grant number: 17/09557-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2017
• End date: July 31, 2018
• Field of knowledge: Health Sciences - Dentistry - Oral and Maxillofacial Surgery
• Principal Investigator: Mariza Akemi Matsumoto
• Grantee: Elisa Mara de Abreu Furquim
• Host Institution: Faculdade de Odontologia (FOA). Universidade Estadual Paulista (UNESP). Campus de Araçatuba. Araçatuba , SP, Brazil

Abstract

Different responses have been brought to light about the development of osteonecrosis of the jaws related to non-resorptive drugs obtained from experimental studies, considering animal model, protocol of drug administration and age. The present study aims to analyze the quality and amount of bone tissue formed inside post-extraction sockets of upper incisors of rats under intravenous (IV) bisphosphonate therapy. Twenty-four male Wistar rats, 20 months old, will be divided in two groups according to the treatment: Control - 0.1 ml of IV 0.9% saline solution, and Group ZL - 0.035 ml/Kg of IV zoledronic acid. The animals from both groups will be treated every 15 days, when the solutions will be administered in the caudal vein until the end of the experiment. After the fourth dose of the solutions, all animals will undergo the extraction of the right upper incisors. After 14 and 28 days from the surgery, the animals will be euthanized for the removal of the hemi-maxillas. The specimens will be immediately fixed in 10% buffered formalin for 48 hours, washed in tap water, and immersed in 70o alcohol to be scanned by a micro computed microtomography (microCT). For the analysis of the alveolar socket, it will be divided into three regions of interest: cervical, medium, and apical. The trabecular bone microarchitecture will be analyzed under the following parameters: bone volume fraction, trabecular number, thickness and separation. After scanning, the specimens will be prepared to be stained with Picrosirius-red for the analysis under polarized light microscopy, in order to permit evaluation of collagenous bone matrix. (AU)