Clinical Investigation of Microbial Profile and Levels of Endotoxins and Lipoteichoic Acid at Different Phases of the Endodontic Treatment in Teeth with Vital Pulp and Associated Periodontal Disease.

Introduction: The aim of this in vivo study was to investigate the microbial profile as well as the levels of lipopolysaccharide (LPS) and lipoteichoic acid (LTA) at different phases of endodontic treatment in teeth with vital pulp and associated periodontal disease.

Methods: Ten patients were selected for this clinical study. Samples were taken from periodontal pockets (PPs) and root canals (RCs) using sterile paper points before and after chemomechanical preparation and after intracanal medication. For microbiological analysis, nested polymerase chain reaction and checkerboard DNA-DNA hybridization were used. Levels of LPS and LTA were assessed using limulus amebocyte lysate and enzyme-linked immunosorbent assays, respectively. Data were statistically analyzed at a significance level of 5%.

Results: Bacterial DNA from 17 of the 17 species investigated was detected in samples of PPs, whereas 6 of the 17 species were not present in the initial samples of RCs using nested polymerase chain reaction. In the initial samples, 38 of 40 probes were detected in PPs, whereas 12 of 40 probes were detected in RCs using checkerboard DNA-DNA hybridization. Overall, endodontic procedures were efficient in modifying the microbiota of PPs and RCs. Levels of LPS and LTA were reduced after the endodontic procedures, although higher concentrations of both had been found in PPs compared with RCs.

Conclusions: The microbiota of PPs and RCs in teeth with vital pulp and associated periodontal disease is polymicrobial, with the presence of gram-negative, gram-positive, facultative, and strict anaerobes. Chemomechanical preparation and calcium hydroxide-based intracanal medication allowed the reduction of infectious content in both sites.