Antibacterial activity of calcium hydroxide-containing endodontic sealers on Enterococcus faecalis in vitro

Antimicrobial activity of endodontic sealers is an important factor in the prognosis of root canal treatment. The aim of this study was to analyse the antimicrobial activity of calcium hydroxide-containing endodontic sealers, Sealapex (SA) and CRCS compared to a ZOE-containing sealer, Roth's cement. The sealers were mixed and placed on the side wall of microtitre plate wells. A 10 microL suspension of Enterococcus faecalis was added to the surface of the sealers 1 h, 24 h, or 7 days after mixture. Bacteria were allowed to come into contact with the sealers for 1 h at 37 degrees C. Fresh media was then added and bacterial growth was measured every 30 min for 16 h. The results showed that in 1-hour-old mixture, CRCS and Roth's cement had a significantly better antimicrobial effect than SA. In 24-hour-old mixtures, ZOE-based sealer showed a more potent antimicrobial activity than calcium hydroxide-containing sealers, whereas SA showed a significantly better antimicrobial effect in the 7-day-old mixture. The antimicrobial activity of each tested sealer changes differently with the time interval between mixing and testing, suggesting different physicochemical properties and potentially diverse clinical applications.