EFFECT OF TREATMENT WITH A PROBIOTICS AS A ROOT CANAL IRRIGATION SOLUTION ON THE POLARIZATION OF MACROPHAGES IN M1 AND M2 SUBTYPES IN PERIAPICAL LESIONS INDUCED IN RATS

• Grant number: 23/09060-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2023
• End date: June 30, 2024
• Field of knowledge: Health Sciences - Dentistry - Pediatric Dentistry
• Principal Investigator: Léa Assed Bezerra da Silva
• Grantee: Gabriela Leite Borges
• Host Institution: Faculdade de Odontologia de Ribeirão Preto (FORP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Periapical lesions are the result of the host's immune-inflammatory response to bacterial infections in root canals, fundamentally from caries lesions. Endodontic treatment aims to eliminate pathogenic microorganisms and promote the resolution of inflammation. Conventional irrigating solutions have limitations in the effective elimination of bacteria and in the modulation of the inflammatory process. In the context of the inflammatory reaction, the fundamental participation of macrophages and the process of polarization of these cells into M1 and M2 subtypes stand out. Recently, probiotics have aroused interest in Endodontics as a promising therapeutic alternative. Thus, the present study aims to evaluate the effect of the probiotic Bifidobacterium animalis subsp. lactis HN019 as a root canal irrigation solution on the polarization of macrophages in subtypes M1 and M2 in periapical lesions induced in rats through immunophenotypic analysis of macrophage subtypes M1 and M2. Slides from a previous study carried out with 44 adult male Wistar rats divided into six experimental groups will be used. Periapical lesions were induced and treated with sodium hypochlorite and Bifidobacterium animalis subsp. lactis HN019. Immunohistochemical analyzes will be performed to determine the polarization of macrophages into M1 and M2 subtypes, and the proportion of subtypes will be evaluated using immunostaining quantification software. Data will be statistically analyzed to compare treatment groups and determine the association between groups and macrophage polarization.