In vitro evaluation of the antibacterial effects of AH26 combined with two different antibiotics on Enterococcus faecalis

To prevent growth of residual bacteria, it has been proposed that sealers and filling materials should have antibacterial properties. The aim of this study was to evaluate the antibacterial effects of AH26 sealer combined with two different antibiotics on Enterococcus faecalis. In this in vitro study, the antimicrobial effects of amoxicillin and minocycline which were added separately to AH26 sealer were evaluated on Enterococcus faecalis. In group 1, 25% amoxicillin with AH26 sealer, in group 2, 25% minocycline with AH26 sealer, in group 3, pure AH26 sealer, and in group 4, distilled water were used. The samples were placed in agar plates inoculated with Enterococcus faecalis. All the plates were incubated for 7 days at 37°C under anaerobic condition, and zones of growth inhibition were measured in millimeters at 24-, 48-, 72- and 7-day intervals. Data were analyzed using 2-way repeated measures ANOVA and multiple comparisons were made by Tukey tests (α=0.05). The results showed that adding antibiotics at 25% concentrations to AH26 sealer created significantly larger zones of growth inhibition compared to the sealer alone (p value < 0.05). In groups 1 and 2, there were significant differences in zones of growth inhibition with an increase in incubation period from 14 to 72 hours; however, there were no significant differences between 72-hour and 1-week intervals. The maximum antibacterial activity was observed in the amoxicillin group. Mixing AH26 sealer with amoxicillin and minocycline significantly increases the antibacterial property of the sealer against Enterococcus faecalis.