Microbiological and fadA family analysis in root canals and periapical lesions of teeth with secondary infection and their relation with the levels of proinflammatory cytokines and MMPs

• Grant number: 17/25090-3
• Support type: Scholarships in Brazil - Post-Doctorate
• Effective date (Start): October 01, 2021
• Effective date (End): September 30, 2023
• Field of knowledge: Health Sciences - Dentistry - Endodontics
• Principal researcher: Brenda Paula Figueiredo de Almeida Gomes
• Grantee: Juliana Delatorre Bronzato
• Home Institution: Faculdade de Odontologia de Piracicaba (FOP). Universidade Estadual de Campinas (UNICAMP). Piracicaba , SP, Brazil
• Associated research grant: 15/23479-5 - Microbiomes and immunobiological aspects in endodontic infections, AP.TEM

Abstract

One of the causes of endodontic treatment failure is a secondary/persistent infection, being Fusobacterium nucleatum, one of the most of the Gram-negative strict anaerobic bacteria frequently found in these cases. F. nucleatum has been shown to invade human epithelial and endothelial cells via FadA adhesin, and consequently alter the human cell cycle, for example by promoting the secretion of pro-inflammatory cytokines and metaloproteinases (MMPs). Thus, the present study aims to evaluate the importance of F. nucleatum in these infections, in relation to the presence of the fadA family and its potential pro-inflammatory effect in root canals and periapical lesions. Patients who need endodontic retreatment due to the failure of the previous treatment with periapical lesion (n = 10) and patients who have undergone endodontic retreatment once, but who have failed again and are indicated for parendodontic surgery for the removal of the periapical lesion (n = 10), will be selected. As a control group, patients with the need for endodontic treatment by prosthetic indication in teeth with pulp vitality (n = 10) will be selected. Samples from the root canals will be collected at three different stages of the endodontic retreatment (before, after chemomechanical preparation and after intracanal medicament) and their DNA extracted. Samples from the periapical lesion will be collected once during the parendodontic surgery. After, 16S rRNA primers will be designed for F.nucleatum and fadA family for gene amplification. Confirmation of the desired gene presence will occur by a band on the electrophoresis gel with the respective expected size. Samples for the measurement of cytokines IL-1±, IL-1², TNF±, and MMP-2, MMP-3, MMP-8, MMP-9, MMP-13 will be quantified at the different stages of the retreatment, using specific kits for determination in human samples by Enzyme-Linked Immunosorbent Assay (ELISA). The antimicrobial susceptibility of Fusobacterium strains isolated and sequenced will be evaluated through Etest. The values obtained will be tabulated and statistically analyzed. (AU)