Endodontic Sealers Incorporating Antibacterial Polyethyleneimine Nanoparticles

Objectives: Endodontic procedural errors are not the direct cause of treatment failure, rather, the presence of pathogens in the incompletely treated or untreated root canal system is the primary cause of periradicular pathosis. Thus, endodontic sealers with antibacterial properties are favorable.We hypothesized that an antibacterial effect may be achieved by incorporating polyethylenimine (PEI) nanoparticles into endodontic sealers. Methods: Test materials included three clinically available endodontic sealers. The sealers' antibacterial effect was tested in vitro against Enterococcus faecalis. The sealers incorporating 0, 0.5, 1 and 2% wt/wt of PEI nanoparticles were tested using the Direct Contact Test (DCT). Results were analyzed using ANOVA followed by a Tukey test.Results: No bacterial growth was detected on AH plus samples incorporating 1% wt/wt PEI after 4 weeks of material aging. AH plus incorporating 2% wt/wt PEI nanoparticles caused significant bacterial growth inhibition after an aging period of 1 week (p<0.05).No bacterial growth was detected on AH26 samples incorporating 1% wt/wt PEI nanoparticles after an aging period of 1 week (p<0.05).Only partial bacterial inhibition was obtained after 4 weeks of material aging (p<0.05). Gutta flow sealer incorporating 2% wt/wt PEI nanoparticles caused strong bacterial growth inhibition after an aging period of 1 week.4 weeks of material aging resulted in partial bacterial inhibition (p<0.05). Conclusion: Endodontic sealers incorporating low concentrations of PEI nanoparticles demonstrate a potent antibacterial effect that lasts at least four weeks.