Cytocompatibility and antimicrobial activity of a novel endodontic irrigant combining citric acid and chlorhexidine

Objectives: This study aimed to evaluate the antibacterial ability and cytocompatibility of a new irrigant solution for endodontic treatment composed of 10% citric acid (CA) and 1% chlorhexidine (CHX). Methods: Thirty-five extracted single-canal human teeth were selected and de-crowned. Canal systems (n = 7/ group) were infected with Enterococcus faecalis for 4 weeks and subject to irrigation with 1% CHX; 10% CA; irrigating solution 10% CA associated with 1% CHX (CACHX); 2.5% NaOCl or sterile water (control). Microbiological samples were collected immediately and 18 h after irrigation (enriched samples). The canals were filled with culture medium post irrigation to verify the bacterial presence/absence qualitatively and quantitatively through colony counting (log10 CFU/mL). A multiparametric assay was performed after exposure of human periodontal ligament fibroblasts (HPdLF) to the test solutions. The Kruskal-Wallis test with Dunn acute accent s post-test and Fisher's exact test were employed at the 95% confidence level to compare differences among groups. Results: All tested solutions were cytocompatible with human periodontal ligament fibroblasts. No difference was observed on antibacterial activity between 1% CHX, 10% CA, CACHX and 2.5% NaOCl (p > 0.05). Eighteen hours after irrigation, CACHX samples were the only that did not present E. faecalis in the root canal system. Conclusions: The demonstrated good in vitro biocompatibility and elimination of E. faecalis suggest a potential use of 10% CA associated with 1% CHX as a solution for microbiological control during endodontic treatment.

Automated summary

This study evaluated the antibacterial ability and cytocompatibility of a new irrigant solution consisting of 10% citric acid and 1% chlorhexidine for endodontic treatment. The results showed that the solution was cytocompatible with human periodontal ligament fibroblasts and had comparable antibacterial activity to other commonly used irrigants. The combination of 10% citric acid and 1% chlorhexidine showed potential as a solution for microbiological control during endodontic treatment.