Antimicrobial Susceptibility of Enterococcus faecalis Isolated From Root Canal: An In Vitro Study

One of the major causes of failure in root canal treatment is microorganisms like Enterococcus faecalis.

This study aimed to examine the effectiveness of triple antibiotic paste (TAP) containing ciprofloxacin, metronidazole, and minocycline in comparison with modified TAP (MTAP) containing metronidazole, ciprofloxacin, and clindamycin and calcium hydroxide on Enterococcus strains isolated from root canal of tooth associated with pre-apical lesion. Moreover, we evaluated the E. faecalis resistance and antibiotic susceptibility. To do so, 25 patients with previous failure of endodontic treatment were enrolled in this study.

The antimicrobial effect of MTAP10%, MTAP1%, TAP10%, TAP1%, and CaOH was significantly better than the positive control group (P <0.05). There was no significant difference between antimicrobial effect of TAP1% and MTAP1%, and CaOH was the least effective one. The antimicrobial effect of TAP10% was significantly better than MTAP10% (P = 0.007). Out of 11 E. faecalis samples, 1 sample was resistant to MTAP1% and MTAP10%, though it was sensitive to other drugs; meanwhile, it showed the highest sensitivity to TAP10%.

TAP10% was the most effective choice followed by MTAP10%, but calcium hydroxide was not effective compared to other choices. Thus, MTAP might be a good choice for root canal medicament instead of TAP