Reduction of viable Enterococcus faecalis in human radicular dentin treated with 1% cetrimide and conventional...

The purpose of this study was to evaluate the viability of E. faecalis after a 14-day exposure to 1% cetrimide (CET), triantibiotic paste (i.e., metronidazole, minocycline, and ciprofloxacin), 2% chlorhexidine (CHX) gel, and calcium hydroxide (Ca[OH]2 ) in an infected dentine model.

A total of 75 roots of extracted uniradicular human teeth were chemomechanically prepared, sterilized, and infected for 21 days with E. faecalis. Samples were divided into five groups (n = 15) to apply intracanal medicaments, namely saline solution (negative control), 1% CET, triantibiotic paste (TRIA), 2% CHX gel, and Ca(OH)2 during 14 days. Dentine samples were collected and stained with the SYTO 9/propidium iodide technique (Live/Dead, Bacligth, Invitrogen, Eugene, OR, USA) for fluorescence microscopy to obtain the percentage of viable cells. Statistical analysis was performed using one-way analysis of variance followed by Tukey's multiple comparison test (P < 0.05).

All experimental agents significantly reduced the percentage of viable E. faecalis when compared with the control group. In addition, the least cytotoxic medicament was Ca(OH)2 followed by CHX. There was no significant difference between 1% CET and TRIA (P = 0.98).

Both 1% CET and TRIA significantly reduced the viability of E. faecalis in dentine of extracted teeth in comparison with 2% CHX gel and calcium hydroxide paste. Further laboratory and clinical investigations should be carried out to validate findings of the beneficial use of 1% CET as an intracanal medicament against E. faecalis.