Chemomechanical preparation influences the microbial community and the levels of LPS, LTA and cytokines in combined endodontic-periodontal lesions: A clinical study

Background This study was conducted to compare the microbiomes, the levels of lipopolysaccharides (LPS), lipoteichoic acid (LTA), and cytokines (interleukin [IL]-1 beta and tumor necrosis factor-alpha [TNF-alpha]), before and after chemomechanical preparation (CMP) of the root canals (RC) and their associated periodontal pockets (PP) in teeth with combined EPL. Materials Samples were taken from 10 RC and PP, before and after CMP. The microbiomes (next-generation sequencing, V3-V4 hypervariable region of the 16S rRNA gene), microbiome diversity (bioinformatics analyses), LPS (limulus amebocyte lysate), LTA, IL-1 beta, and TNF-alpha (ELISA) were evaluated. A statistical analysis was performed with significance level set at 5%. Results The most abundant phyla in both sites were Firmicutes and Proteobacteria. Comparative studies of bacterial genera species revealed that some increased and others decreased after CMP at both sites. A 3% reduction in Gram-negative bacteria (RC) and a 4% increase in Gram-positive bacteria (PP) were detected. LPS levels were 4.4 times higher in PP than in the RC. LTA was detected in all samples investigated. Higher levels of IL-1 beta and TNF-alpha were detected in both sites at baseline. After CMP, LPS, LTA, IL-1 beta and TNF-alpha were reduced in both sites. Conclusion The microbial community in the RC and PP in teeth with combined EPL indicated a similarity between both sites. CMP effectively reduced the microbial load and the LPS levels from teeth with EPL, and consequently diminished the cytokine levels. The reduction in LTA levels in the RC and PP proved challenging.

Automated summary

The study compared the microbiomes, levels of LPS, LTA, and cytokines before and after chemomechanical preparation of the root canals in teeth with combined EPL. Results showed that CMP effectively reduced microbial load and LPS levels, leading to decreased cytokine levels in both the root canals and periodontal pockets.