Ex-vivo evaluation of intratubular antibacterial activity and biocompatibility of two hydraulic calcium silicate-based endodontic sealers

Purpose: This study evaluated the antibacterial activity of two hydraulic calcium silicate-based sealers, NeoSealer Flo and AH Plus Bioceramic, against Enterococcus faecalis (E. faecalis) biofilm and their biocompatibility with pre-osteoblastic cells. Methods: Thirty-one extracted human lower incisors with single canals were inoculated with E. faecalis, and their root canals were subjected to three types of filling: A) NeoSealer Flo (n = 10), B) AH Plus Bioceramic (n = 10), and C) positive control (n = 10), as well as one negative control. The teeth were embedded in resin and sectioned at their coronal, middle, and apical thirds, yielding 160 sections. Bacterial viability was assessed by confocal laser scanning microscopy using LIVE/DEAD staining. Biocompatibility was evaluated using the bicinchoninic acid protein assay and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Results: NeoSealer Flo and AH Plus Bioceramic showed comparable antibacterial activity. In the coronal third of the tooth, viable bacteria were estimated at 44.1 ± 4.0% and 43.5 ± 4.0%, respectively, versus 85.7 ± 5.2% in controls. Similar results were obtained in the middle and apical thirds. Viability was significantly higher in the coronal third (P < 0.05). No significant differences in cell number or protein expression were observed between the sealers and the controls (P > 0.05). Conclusion: Both sealers demonstrated similar antibacterial effectiveness and biocompatibility, with greater bacterial viability in the coronal region.