Evaluation of the antibacterial activity of three gutta-percha solvents against Enterococcus faecalis

Abstract

Purpose: Enterococcus faecalis (E. faecalis) is implicated as the common etiological agent of root canal treatment failure. The study was aimed to compare the antibacterial efficacy and to assess the minimum inhibitory concentration (MIC) of 3 gutta-percha solvents-RC Solve, Endosolv-E, and xylene against E. faecalis.

Methods: Agar well diffusion assay was performed to evaluate the antibacterial efficacy of the gutta-percha solvents against E. faecalis (ATCC 29212 and a clinical isolate). The standard drug vancomycin was used as the control. The MIC of the solvents was determined by broth microdilution assay. Two fold serial dilutions of the solvents were prepared and the lowest concentration of the solvent that inhibits visible bacterial growth was recorded as the MIC. Minimum bactericidal concentration (MBC) was determined by plating on Muller Hinton Agar plates and the lowest concentration of the solvent that resulted in 99% reduction of bacterial viability was scored as the MBC.

Results: The antibacterial activity of RC Solve against E. faecalis was found to be comparable to that of the standard drug-vancomycin. Xylene did not exhibit antibacterial activity while the antibacterial activity of Endosolv-E was lesser than RC Solve. RC Solve recorded lower MIC values against both E. faecalis ATCC29212 and clinical isolate (1:2 and 1:4 dilution) than Endosolv-E (undiluted). RC Solve was found to possess antibacterial activity against E. faecalis even at half the concentration that is routinely being used.

Conclusions: Within the limitations of the study, we conclude that RC Solve can perform a dual role both as a gutta-percha solvent as well as a microbicide against E. faecalis.