EDTA treatment diminishes the antibacterial and anti-adherence effect of calcium hydroxide on Enterococcus faecalis : an in vitro study

This study sought to understand the cell surface characteristics, viability and biofilm-forming potential of Enterococcus faecalis cells sequentially exposed to EDTA and calcium hydroxide, as in endodontic treatment. Bacterial cells exposed to EDTA and calcium hydroxide were assayed for cell viability, membrane integrity, cell surface hydrophobicity and surface charge, while alteration in the surface topography of E. faecalis cells was examined using atomic force microscopy (AFM). The bacterial adherence potential to type I collagen was also examined to assess the biofilm-forming capacity of E. faecalis cells exposed to EDTA and calcium hydroxide. It was found that calcium hydroxide treatment reduced the viability of E. faecalis . However, prior exposure to EDTA significantly reduced the antibacterial effect of calcium hydroxide ( P P E. faecalis to type I collagen. These effects due to calcium hydroxide were also significantly altered in EDTA-pretreated cells ( P E. faecalis cells to EDTA.