In vitro evaluation of antibacterial activities of root canal sealers.

Objective: The purpose of this study was to compare the antimicrobial effect of AH-26 (a resin-based sealer), Dorifill (a ZOE-based sealer), and pure ZOE after 24 hours and after one week.

Methodology: All sealers were prepared according to the manufacturers' directions immediately before testing. The micro-organisms used in this assay included Staphylococcus aureous and Streptococcus mutans, which were prepared from isolated species in the microbiology laboratory. The antimicrobial effects of each sealer were determined by measuring the diameter of the zone of inhibition in millimeters after incubation at 37 degrees C for 24 hours and seven days in a humid atmosphere. Each test was repeated three times.

Results: In the 24-hour samples, the antibacterial activity of AH-26 was significantly greater than two other materials tested on both bacteria (p < 0.05). The antibacterial activity of Dorifill and ZOE on S. aureous was not significantly different from each other (p > 0.05), but Dorifill had a significantly greater effect on S. mutans than ZOE (p < 0.05). In the seven-day samples, statistically significant zones of bacterial growth inhibition for both bacterial species tested were observed in descending order of antibacterial activity as ZOE > AH-26 > Dorifill (p < 0.05).

Conclusion: The products studied exhibited some variable antibacterial properties. In 24 hours, the AH-26 exerted the greatest activity against both organisms tested. By seven days, the ZOE-based sealer-Dorifill-showed lower antibacterial activity than AH-26 and pure ZOE.