Molecular evaluation of the apical microbiota of the root canal of teeth subject to cryogenic grinding

• Grant number: 23/10620-8
• Support Opportunities: Scholarships in Brazil - Master
• Start date: September 01, 2024
• End date: February 28, 2025
• Field of knowledge: Health Sciences - Dentistry - Endodontics
• Principal Investigator: Brenda Paula Figueiredo de Almeida Gomes
• Grantee: Larissa de Souza Oliveira
• Host Institution: Faculdade de Odontologia de Piracicaba (FOP). Universidade Estadual de Campinas (UNICAMP). Piracicaba , SP, Brazil

Abstract

The complex anatomy of the root canal system negatively interferes with the root canal disinfection process, especially in the apical third. In addition, microbial resistance, and its ability to adapt to environmental changes and grow in biofilm favors the permanence of these bacteria in root canals and dentinal tubules, being the main cause of failure of endodontic treatment. The objective of the study is to investigate the profile of the microbiota established in the apical segment of the root canal of teeth extracted with unsuccessful endodontic treatment. Fifteen extracted teeth will be collected for presenting clinical and radiographic evidence of primary endodontic treatment failure, and without the possibility of endodontic reintervention. As a control group, fifteen teeth with vital pulp indicated for extraction for orthodontic or prosthetic reasons or due to patient complaints, such as in cases of third molars, will be used. After the extraction, disinfection of the tooth surface and neutralization of the chemical substances used will be performed, and the sample will be stored and frozen in a sterile 15 mL Falcon tube in a freezer at -20°C for future analysis. A 6750 Freeze Mell (Spex, Metuchen, NJ) will be used to cryogenically grind each tooth fragment. DNA will be extracted from the samples containing root powder using the QIAmp DNA Mini Kit (Qiagen, Valencia, CA) following the manufacturer's recommended protocol. Microbiological analyzes will be performed using Checkerboard DNA-DNA Hybridization and Nested PCR using specific primers for bacteria and fungi. After performing and processing the data, they will be tabulated so that the statistical analysis After can be performed using the SPSS software for Windows.