Advancements in chitosan nanoparticles as root canal irrigation agents: A scoping review

Aim: This review systematically analyzes recent advancements in chitosan nanoparticle (CNP) technology as a root canal irrigation material. By comparing CNPs with conventional irrigants, it explores their advantages in enhancing endodontic disinfection while minimizing adverse effects, improving clinical outcomes. Methods: A literature search was conducted in PubMed, ScienceDirect, Wiley Online Library, and Scopus for the English language articles published from 2014 to 2024. Articles with unclear data, unspecified sample sizes, or insufficient methods were excluded. Study selection followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Results: Out of 804 initially identified articles, 12 met the inclusion criteria. Quality assessment was performed using a revised diagnostic accuracy appraisal tool. The selected in vitro and ex vivo studies consistently demonstrated that CNPs exhibit superior antibacterial efficacy – particularly against Enterococcus faecalis and Streptococcus mutans – compared to NaOCl, ethylenediaminetetraacetic acid, and chlorhexidine. Methylene blue CNPs (MB-CNPs) in photodynamic therapy (PDT) improved bacterial elimination, smear layer (SL) removal, and bond strength with minimal cytotoxicity. CNPs combined with rose bengal and diode laser also enhanced disinfection outcomes. Additional findings revealed that CNPs preserved dentin microhardness, improved push-out bond strength, and supported dental stem cell proliferation – especially when combined with transforming growth factor-beta 1 – suggesting regenerative potential. Measurements across studies (colony-forming unit counts, scanning electron microscopy, confocal laser scanning microscopy, Vickers hardness, ELISA, CCK-8, MTT assays, and molecular docking) were consistently applied. Conclusion: CNP-based irrigants outperform conventional materials in antimicrobial action, SL removal, biocompatibility, and regenerative support. Innovations such as MB-CNPs in PDT offer a promising, next-generation approach to improving disinfection and clinical outcomes in endodontic therapy.