In vitro evaluation of the antimicrobial effects of a root canal sealer-antibiotic combination against Enterococcus faecalis

The purpose of this in vitro study was to evaluate the antimicrobial effects of five antibiotics when added to Kerr Pulp Canal Sealer EWT against Enterococcus faecalis. Five antibiotics: amoxicillin, penicillin, clindamycin, metronidazole, and doxycycline, were added separately to Kerr sealer. Thirty brain heart infusion agar plates were inoculated with E. faecalis and sterile paper discs containing a sealer-antibiotic combination were randomly assigned to the inoculated plates. Kerr sealer on a sterile paper disc and a blank sterile paper disc served as the controls. Fifteen plates were incubated aerobically and the remaining 15 plates were incubated anaerobically at 37 degrees C. The zones of inhibition were measured at 48 hours. No significant differences (p > 0.05) were found between aerobic and anaerobic groups. The groups were combined and data analysis using a one-way ANOVA and Tukey's post hoc test was performed. Results revealed that sealer-antibiotic combinations containing amoxicillin, penicillin, clindamycin, and doxycycline had a significant difference (p < 0.001) in the mean zones of inhibition when compared to Kerr EWT sealer alone. No significant differences (p > 0.05) were found between the metronidazole-sealer combinations and Kerr EWT sealer alone.