Toward Antibacterial Endodontic Sealing Materials

Methods: : Antibacterial effect against a persistent endodontic pathogen, Enterococcus faecalis, was evaluated using: (i) agar diffusion test and (ii) direct contact test and (iii) electron microscopy. QPEI nanoparticles were incorporated into AH plus (DENTSPLY DeTrey GmbH, Germany) and GuttaFlow (Coltène whaledent, Germany) at concentrations of 0.5%, 1%, or 2% wt/wt. Data was analyzed using ANOVA followed by a Tukey test.

Results: The antibacterial tests exhibited total bacterial growth inhibition in the 4 weeks aged AH plus samples incorporating 1% wt/wt QPEI nanoparticles (p<0.00001). GuttaFlow samples exhibited partial bacterial growth inhibition. A significant bacterial growth inhibition was observed in both modified endodontic sealers incorporating at least 1% w/w nanoparticles (p < 0.05). A significant bacterial growth inhibition was observed in modified sealers incorporating at least 1% w/w nanoparticles in both tested materials (p < 0.05). Material characterization tests showed QPEI nanoparticles did not leach to the surrounding milieu, while scanning electron micrographs indicate bacterial cell wall damage and cell lysis.

Conclusions: In conclusion, endodontic materials incorporating low concentrations of QPEI nanoparticles exhibited significant and stable antimicrobial properties.