Evaluation of antimicrobial effects of 3 antibiotic paste with different concentration on mature Enterococus faecalis biofilm at 1 , 2 3 and 4 week intervals

Abstract

Triple antibiotic paste (TAP) is widely used in endodontics for root canal disinfection, particularly in regenerative procedures. The aim of this in vitro study was to evaluate the antimicrobial effects of different concentrations of TAP at 1-, 2-, 3-, and 4-week intervals on mature Enterococcus faecalis biofilm. Methods: A total of 287 extracted one-rooted human central incisors were infected with E. faecalis ATCC 29212 after removing the crown and preparation. The root canal space was filled with one of the 0.01-, 0.1-, 1-, 10-, 100-, and 1000-mg/mL concentrations of TAP or normal saline (control). The root canal dentin was sampled after 1, 2, 3, and 4 weeks. The dentinal chips were cultured on Mueller-Hinton agar plates after serial dilutions. The classic colony-forming unit (CFU) counting technique was used to determine remaining bacterial counts (P<0.05). Results: TAP completely eliminated E. faecalis biofilms at all the intervals at concentrations of 1000, 100, and 10 mg/mL, whereas 1-, 0.1-, and 0.01-mg/mL TAP resulted in significant reduction of CFU means compared with the control group. There were no statistically significant differences between the four time intervals. Conclusions: Use of lower concentrations of TAP at short term could eradicate E. faecalis biofilm and decrease high-concentration side effects.