Antimicrobial Activity of Phytic Acid: An Emerging Agent in Endodontics.

Background: Phytic acid (IP6) is a promising and emerging agent that lends itself to several applications in dentistry due to its unique structure and distinctive properties. Recently, IP6 was proposed as a potential chelating agent in endodontics. However, there is limited knowledge regarding its antimicrobial and antibiofilm effectiveness. Hence, the aims of this study were to evaluate the antimicrobial and antibiofilm activities of IP6 against a range of microbial species and compare these with ethylenediaminetetraacetic acid (EDTA) and sodium hypochlorite (NaOCl). The contact time required for IP6 to exert its bactericidal effect on Enterococcus faecalis was also determined. Methods: The inhibitory and biocidal activities of IP6, EDTA and NaOCl were assessed using a broth microdilution assay against 11 clinical and reference bacteria and a reference fungus. The contact time required for various concentrations of IP6 to eliminate planktonic cultures of E. faecalis was determined using a membrane filtration method according to a British Standard (BS-EN-1040:2005). IP6 bactericidal activity was also evaluated using fluorescent microscopy. The antibiofilm activity of the test agents was also determined. Results: IP6 was biocidal against all tested microorganisms. At concentrations of 0.5%, 1% and 2%, IP6 required 5 min to exert a bactericidal effect on E. faecalis, while 5% IP6 was bactericidal after 30 s. IP6 also eradicated biofilms of the tested microorganisms. In conclusion, IP6 had notable antimicrobial effects on planktonic and biofilm cultures and was exhibited rapid bactericidal effects on E. faecalis. This work highlights the antimicrobial and antibiofilm properties of IP6 which could be exploited not only in dentistry applications, but also other fields where novel strategies to counter antimicrobial resistance is required. Further in vitro and in vivo studies are required to fully understand its mechanism and efficacy.