Comparative evaluation of the concentration-dependent effect of proton-pump inhibitor in association with calcium hydroxide and chlorhexidine on Enterococcus faecalis: An in vitro study

J Oral Maxillofac Pathol. 2021 Jan-Apr;25(1):198. doi: 10.4103/jomfp.JOMFP_303_20. Epub 2021 May 14.

Abstract

Background: Enterococcus faecalis is the most persistent organism in the root canal which resists most of the intracanal medicaments. There is always a constant attempt to eliminate this endodontic pathogen from the root canal system.

Aim: The aim of this study was to evaluate the efficacy of the association of different concentrations of proton-pump inhibitor (PPI) (Lansoprazole) with calcium hydroxide (CH) and chlorhexidine (CHX) against E. faecalis using a broth dilution method.

Materials and methods: E. faecalis was inoculated into brain-heart infusion broth at 37°C for 5 h. The master broth was then treated with CH (Group 1); CH + 2% CHX (Group 2); CH + PPI 6.25 μg/ml (Group 3A); CH + PPI 25 μg/ml (Group 3B); 2% CHX + PPI 6.25 μg/ml (Group 4A); 2% CHX + PPI 25 μg/ml (Group 4B); CH + 2% CHX + PPI 6.25 μg/ml (Group 5A), and CH + 2% CHX + PPI 25 μg/ml (Group 5B). The groups were spectrophotometrically analyzed at 630 nm at 24 h to determine the group with the least optical density.

Statistical analysis: Comparison between the groups was done by the one-way analysis of variance and Kruskal-Wallis test for multiple comparisons.

Results: The mean percentage inhibition of E. faecalis by Group 5A (CH + 2% CHX + PPI 6.25 μg/ml) was the highest compared to other groups. The lowest mean value was observed in Group 3A (CH + PPI 6.25 μg/ml) indicating least efficiency.

Conclusion: There was a concentration-dependent effect of PPI on CH and CHX against E. faecalis. The maximum efficacy was found when the lower concentration of PPI was associated with CH/CHX mixture.

Keywords: Calcium hydroxide; Enterococcus faecalis; chlorhexidine; intracanal medicaments; proton-pump inhibitors; root canal; spectrophotometry.