JMIR Publications

ABSTRACT

Background:

Enterococcus faecalis is a facultative anaerobic bacterium frequently associated with persistent root canal infections and endodontic treatment failures. Its resistance is primarily attributed to its ability to form robust biofilms, survive under harsh conditions, and penetrate deep into dentinal tubules. Chlorhexidine gluconate (CHX), commonly used as an intracanal medicament, exhibits broad-spectrum antimicrobial activity; however, its limited ability to eliminate biofilms, potential cytotoxicity, and restricted dentinal penetration pose significant drawbacks. In recent years, nanotechnology has introduced promising alternatives, such as cerium oxide nanoparticles (CeO₂-NPs), which exhibit unique redox properties, reactive oxygen species (ROS) scavenging, and antimicrobial action due to their nanoscale size and surface chemistry.

Objective:

This study aims to evaluate and compare the antimicrobial efficacy of CeO₂-NPs, 2% CHX, their combination, and sterile water against E. faecalis biofilms in root canal systems.

Methods:

Forty-eight extracted human single-rooted premolars will be decoronated, instrumented, and sterilized. The root canals will be inoculated with E. faecalis and incubated to allow biofilm formation over a standardized period. The specimens will then be divided into four groups (n=12 per group), each receiving one of the following treatments: CeO₂-NPs, 2% CHX, a combination of CeO₂-NPs and CHX, or sterile water as the negative control. After the medicaments are applied for a predetermined contact time, microbial sampling will be conducted, and the remaining viable bacteria will be quantified using colony-forming unit (CFU) counts on selective agar.

Results:

The anticipated results will include comparative CFU counts for each treatment group. A reduction in CFU levels will indicate the antimicrobial effectiveness of the test medicaments. It is hypothesized that the combination of CeO₂-NPs and CHX will yield the most significant reduction in bacterial load, followed by CeO₂-NPs alone, CHX alone, and sterile water.

Conclusions:

This study aims to provide insight into the antimicrobial potential of cerium oxide nanoparticles, either alone or in combination with chlorhexidine, against E. faecalis biofilms. If proven effective, CeO₂-NPs could represent a novel and biocompatible adjunct or alternative to conventional intracanal medicaments, contributing to improved disinfection protocols and better clinical outcomes in endodontic therapy. Clinical Trial: Since this investigation will be conducted entirely as an in vitro study, registration with the Clinical Trials Registry - India (CTRI) was not applicable and therefore not required.