Antibacterial, biological, and physicochemical properties of root canal sealers containing chlorhexidine-hexametaphosphate nanoparticles

Objective. The aim of this study was to evaluate the influence of the incorporation of chlorhexidine-hexametaphosphate nanoparticles (CHX-HMP NPs) on antibacterial, cyto-toxic and physicochemical properties of AH Plus (AH), MTA Fillapex (MTA) and Pulp Canal Sealer (PCS). Methods. The NPs were synthesized and characterized by Scanning Electron Microscopy (SEM), Dynamic Light Scattering (DLS), zeta potential, Atomic Force Microscopy (AFM) and Energy-Dispersive X-ray Spectroscopy (EDS). The incorporation was made by weight, 2% and 5% of NPs. The antimicrobial activity, cytotoxicity, flow, radiopacity, setting time, solu-bility and pH were evaluated. The statistical analysis was performed by two-way analysis of variance test and Tukey post hoc test (P < 0.05). Results. SEM analysis showed the tendency for CHX-HMP NPs to cluster, the effective mean diameter measured by DLS: 169.39 nm and the zeta potential:-10.18 mV. The NPs were indi-vidually measured by AFM: 22.99?52.75 nm. EDS analysis identified the presence of C, N, O, Na, P, Cl. After incorporation: The Direct Contact Test showed an increase in the antimi-crobial action of AH, PCS and MTA; the sealers showed a decrease in flow and at 24 h of immersion also an increase in solubility, but did not affect the radiopacity of the samples; AH setting time increased and MTA did not reach setting under any of the conditions tested. All samples showed a decrease in pH value as the immersion time progressed. Significance. The incorporation of NPs can improve the antimicrobial performance of endodontic sealers without impairing other biological and physicochemical properties. ? 2021 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.

Automated summary

The study demonstrates that incorporation of chlorhexidine-hexametaphosphate nanoparticles can enhance the antimicrobial performance of endodontic sealers without impairing other biological and physicochemical properties.