Lethal bacterial trap: Cationic surface for endodontic sealing

Insoluble antibacterial cationic nanoparticles have been previously shown to have potent and long‐lasting antibacterial properties. Our tested hypothesis was that root canal pathogens will be attracted to and eliminated when exposed to epoxy resin‐based surfaces incorporating cationic nanoparticles. In our research, an epoxy resin‐based surface incorporating quaternary ammonium polyethyleneimine (QPEI) nanoparticles was evaluated. Surface characterization was performed using atomic force microscopy and X‐ray photoelectron spectra. The surface anti‐Enterococcus faecalis effect was evaluated in an anti‐gravitational model. Cell membrane potential, viability, biofilm thickness, and biomass were tested using flow cytometry and confocal laser scanning microscopy. Additionally, the antibiofilm activity of the bacterial supernatant was assessed. The surface characterization showed QPEI nanoparticle embedment on the modified sealer. The epoxy resin‐based surface incorporating the QPEI nanoparticles actively attracted bacteria, causing membrane destabilization, and bacterial death. The supernatant of bacteria pre‐exposed to QPEI showed an antibacterial effect. In conclusion, the tested epoxy resin‐based surface incorporating QPEI nanoparticles traps and kills bacteria. The nanoparticles attracted bacteria, reducing their viability, and promoting cell death. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 427–434, 2016.