Behavioral evaluation and volume of periapical injuries induced in rats submitted to different radiotherapy protocols

• Grant number: 20/13269-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: February 01, 2021
• End date: December 31, 2021
• Field of knowledge: Health Sciences - Dentistry - Endodontics
• Principal Investigator: Marcia Carneiro Valera Garakis
• Grantee: Ítza Amarísis Ribeiro Pinto
• Host Institution: Instituto de Ciência e Tecnologia (ICT). Universidade Estadual Paulista (UNESP). Campus de São José dos Campos. São José dos Campos , SP, Brazil

Abstract

A diagnosis of Head and Neck Neoplasms is treated in most cases using radiotherapy (RT). This method is chosen for its high success rate in reducing the size of the tumor, regardless of stage, although it is not possible to avoid the side effects of this treatment. The individuals will present severe debilities in the quality of life such as hyposalivation and even a suppression of blood supply that results in a predisposition to osteoradionecrosis. In addition, changes in the oral microbiota and root canal are also consequences of this treatment. Apical periodontitis (AP) is a pathology common to a Brazilian population, although few studies have been conducted on this pathology in a patient who undergoes RT. To determine the care protocols with greater scientific basis without further prejudice to these debilitated patients, it is necessary to use animals to perform these studies for later use of the data obtained for clinical application. The present project will evaluate the development of BP in rats under different radiotherapy protocols. For this evaluation, 60 male Wistar rats will be allocated to 6 groups (n = 10) according to the irradiation dose: RT-7.5 (single dose of 7.5 Gy); RT-10 (single dose of 10 Gy); RT-15 (single dose of 15 Gy); RT-30 (single dose of 30 Gy); Control-PA (without RT and PA induction); Control (without RT and without PA). The animals will be irradiated in the region of the right face and after 7 days of RT, periapical lesion will be induced. For BP induction, as pulp cavities of the first molars will be exposed to the oral environment for 21 days. During the study the animals will undergo behavioral analysis. After 21 days of PA induction, blood will be collected for analysis of corticosterone levels and the apical region of the first molars will be subjected to an analysis by computerized microtomography,to assess an area and the volume of the PA. The data will be obtained by descriptive and inferential statistical tests, according to data obtained, according to their normality, in parametric and non-parametric tests.