Microbial profile and effect of intracanal medication on endodontic bacteria, LPS and LTA in teeth with pulp necrosis and apical periodontitis

Abstract

The anatomical complexity and limitation of biomechanical preparation (PBM) make it necessary to use different intracanal medications (MIC) in order to combat resistant microorganisms and intraradicular biofilm. Therefore, this research project aims to trace the microbiological profile, quantify LPS and LTA during endodontic treatment using intracanal medication with chlorhexidine associated with Ca(OH)2 or N-acetylcysteine (NAC) in teeth with primary endodontic infection in healthy patients. . For this, 30 teeth of healthy patients with primary endodontic infection, single-rooted, with the presence of a single canal and radiographically proven periapical lesion will be used. The teeth will pass through the coronal opening and first collection (S1), biomechanical preparation with a reciprocating instrument and irrigation with 2.5% sodium hypochlorite followed by the second collection (S2) and divided into two groups with different MIC G1: Calcium hydroxide and chlorhexidine [Ca(OH)2 + CLX] and G2: N-acetylcysteine + chlorhexidine (NAC + CLX). After 14 days, the third collection of canal content will be performed (S3) and the teeth will be filled and restored. The collected content will be evaluated through the following tests: Detection and quantification of lipoteichoic acid - LTA (ELISA), quantification of endotoxins (LPS) by the chromogenic kinetic assay of limulus amoebocyte lysate (LAL), microbiological analysis by Checkerboard DNA-DNA hybridization. Data will be evaluated by descriptive and inferential statistical tests, according to data obtained, according to their normality, with parametric or non-parametric tests.