Attract to kill – antibacterial cationic surfaces for endodontic sealing

Objectives: Cationic nanoparticles have potent and long-lasting antibacterial properties. We hypothesized that epoxy resin-based surfaces incorporating cationic nanoparticles attract and eliminate root canal pathogens.
Methods: The surface anti- Enterococcus faecalis effect of an epoxy resin-based endodontic sealer incorporating cationic nanoparticles was evaluated using an anti-gravitational model. Atomic force microscopy and X-Ray photoelectron spectra were used for surface characterization. Cell membrane potential, viability, biofilm thickness and biomass were tested using flow cytometry and confocal laser scanning microscopy. Additionally, the anti-biofilm activity of the bacterial supernatant was assessed.

Results: Incorporation of cationic nanoparticles resulted in E. faecalis attraction, membrane destabilization and bacterial death. Surface characterization showed cationic nanoparticle embedment on the modified sealer. Moreover, the supernatant of E. faecalis pre-exposed cells to cationic nanoparticles showed an antibacterial effect.
Conclusions: Epoxy resin-based surface incorporating cationic nanoparticles traps and kills bacteria. The nanoparticles attract bacteria, reduce their viability and promote cell death.