Summary
The success of endodontic treatments is related to the neutralization of bacteria and their toxins, inside and outside the root canal system of a tooth. Usually this is achieved, under ideal conditions, by means of a chemicalmechanical action (endodontic files and irrigation with appropriate solutions). Silver nanoparticles (AgNPs) are well-known for their antibacterial properties, and, for this reason, the aim of this work was to modify the surface of Nickel-Titanium (NiTi) endodontic files with AgNPs, to confer them antimicrobial ability and avoid infections. For this purpose, the preparation and characterization of stable colloids of AgNPs were carried out. Ten NiTi files for endodontics (brand K3 XF, Sybron-Endo Keer) were divided into 2 groups; 5 for group 1 (control, files as received) and 5 for group 2 (files previously coated with AgNPs). Both groups were subjected to biofilm formation using a culture composed of Candida albicans and Enterococcus faecalis, in an anaerobic environment. Endodontic files were successfully modified with silver nanoparticles, and, after exposure under anaerobic conditions to the selected microorganisms. Scanning electron microscopy revealed the proliferation of microorganisms on the surface of the control files. In contrast, the modified and coated files showed no biofilm formation, and the bacteria exhibited changes in cell wall morphology, likely associated with wall rupture and subsequent cell death. The coating of silver nanoparticles on the surface of the files shows to change the morphology of the bacterial wall, causing death and thus inhibition in formation of microbiological biofilms. Since reactive oxygen species (ROS) are unlikely to be present under the anaerobic conditions used, the microbicidal effect of the nanoparticles indicates that ROS-promoted oxidative stress is not an important mechanism of action, and inactivation of thiol-containing proteins could be a more important mechanism.
KEY WORDS: antimicrobial activity, Candida albicans, endodontic files, Enterococcus faecalis, silver nanoparticles.
How to cite this article
RAMÍREZ-GONZÁLEZ, J. H.; SÁNCHEZ-LOREDO, M. G.; LABRADA-DELGADO, G. J.; GONZÁLEZ-AMARO, A. M. MÉNDEZ-GONZÁLEZ, M. V. & ZAVALA-ALONSO, N. V. Surface modification of endodontic files with silver nanoparticles for antimicrobial purposes. Int. J. Odontostomat., 19(1):45-54, 2025.
