Chemical, antibacterial and cytotoxic properties of four different endodontic sealer leachates over time

Abstract

IntroductionThe management of apical periodontitis involves the elimination of bacteria to achieve healing of the periapical tissues. To this end, understanding of the antimicrobial properties and cytotoxicity of root canal sealers over time is important. This study aimed to assess the cytocompatibility and antibacterial activity of leachates obtained from selected endodontic sealers. MethodsFour sealers were used in this study; AH Plus, an epoxy resin-based sealer, and three hydraulic calcium silicate-based sealers: AH Plus Bioceramic, BioRoot RCS and BioRoot Flow. Sealer chemistry was assessed by scanning electron microscopy and energy dispersive spectrum analysis. Leachates of the tested sealers were prepared by immersing sealer discs in HBSS for 28 and 90 days. Element release was assessed using inductively coupled plasma mass spectroscopy. Enterococcus faecalis and Fusobacterium nucleatum were exposed to the leachates followed by CFU determination, and the human osteoblast-like cell line Saos-2 was assessed with regard to cell death, caspase expression and activity of alkaline phosphatase after stimulation with the leachates. ResultsCalcium leaching was detected in the tricalcium silicate-based sealers, which increased the leachate pH significantly (p<0.0001). AH Plus Bioceramic leachate displayed antimicrobial activity at 28 days against E. faecalis (p<0.01). Alkaline phosphatase levels were reduced in response to AH Plus Bioceramic and BioRoot RCS 1-day leachates (p<0.05). High cell viability was observed after exposure to all sealers. ConclusionsThe leachates of the tested sealers were cytocompatible, however, their antimicrobial activity as well as their potential to induce the bone formation marker alkaline phosphatase was minimal.