Abstract

Elimination of Enterococcus faecalis (E. faecalis) biofilms from the root canal system is a challenging issue in endodontics. The objective of this in-vitro study was to evaluate the antibacterial efficacy of ultrasonic-activated herbal irrigants (black walnut and wormwood) and inorganic salts (alum and sodium chloride) against E. faecalis biofilms, compared with conventional irrigation. E. faecalis (MTCC 439) biofilms were grown on microtiter plates and treated with the test irrigants with and without ultrasonic activation for 5 and 10 minutes. Antibacterial efficacy was determined by Minimum Biofilm Eradication Concentration (MBEC) analysis using crystal violet staining and optical density measurement, and fluorescence microscopy using acridine orange and ethidium bromide staining to distinguish live and dead cells. All irrigants showed increased antibacterial activity when combined with ultrasonic activation (p < 0.05), with black walnut showing the highest biofilm reduction followed by wormwood, alum, and sodium chloride. A 10-minute exposure time caused significantly greater biofilm disruption than 5 minutes. Ultrasonic activation dramatically enhances the antibacterial potential of herbal and inorganic irrigants, with black walnut, wormwood, and alum showing promise as adjuncts to conventional endodontic disinfection protocols.

Key words: Alum, biofilm, black walnut, Enterococcus faecalis, fluorescence microscopy, herbal irrigants, Inorganic salt, MBEC, NaCl, Ultrasonic irrigation, wormwood