Fe₃O₄-MXene as a dual-function root canal agent for disinfection and osteoclast inhibition in persistent apical periodontitis.

Abstract

Persistent apical periodontitis (PAP) is characterized by periapical inflammation and alveolar bone resorption resulting from microorganisms that are resistant to conventional root canal disinfection. The treatment goals for PAP are to effectively eliminate resistant microorganisms and inhibit bone resorption. Root canal therapy (RCT) is the primary treatment for PAP, with chemical disinfection being a fundamental step in the process. This study developed Fe₃O₄‒MXene, a new root canal disinfectant with photothermally induced antibacterial properties and the potential to inhibit bone resorption. Under 808 nm light, Fe₃O₄‒MXene demonstrated high performance in converting the light energy into heat, effectively inhibiting Enterococcus faecalis (E. faecalis) biofilms. Additionally, Fe₃O₄‒MXene-mediated photothermal therapy enhanced the ability of NaOCl to eliminate E. faecalis contamination from the root canal system. Furthermore, magnetically guided to periapical areas, Fe₃O₄‒MXene suppressed osteoclast differentiation and function by neutralizing intracellular reactive oxygen species, downregulating NF-κB and NFATc1 pathways, which are critical regulators of osteoclast differentiation. In conclusion, Fe₃O₄‒MXene is a promising new root canal disinfectant that may improve PAP outcomes by simultaneously targeting root canal infection and alveolar bone resorption. STATEMENT OF SIGNIFICANCE: The pathology of PAP involves intracanal infection and bone resorption in the periapical area. Current research primarily focuses on eliminating intracanal contamination, while periapical lesions are often overlooked. To address this limitation, this study introduces Fe₃O₄‒MXene as an innovative root canal disinfectant with dual antibacterial and anti-resorptive effects. Fe₃O₄‒MXene combines photothermal antibacterial activity with targeted inhibition of osteoclastogenesis to address both infection and bone loss. Its synergistic antimicrobial effect with NaOCl and magnetic targeting enhances treatment precision and efficacy, providing a new and multifunctional therapeutic approach for PAP treatment.