ENDODONTIC IRRIGANTS: A COMPREHENSIVE REVIEW

Abstract

Effective root canal irrigation is a critical component of endodontic therapy, aiming to achieve thorough disinfection, debris removal, and smear layer elimination. While mechanical instrumentation is essential, it cannot fully clean the complex anatomy of root canal systems, necessitating the use of irrigants with complementary chemical properties. This review explores the characteristics, mechanisms of action, advantages, limitations, and clinical applications of the most commonly used endodontic irrigants: sodium hypochlorite (NaOCl), chlorhexidine (CHX), and ethylenediaminetetraacetic acid (EDTA). Sodium hypochlorite remains the gold standard due to its dual ability to dissolve organic tissue and eliminate microorganisms, but it is limited by its cytotoxicity and inability to remove the inorganic smear layer. Chlorhexidine, known for its antimicrobial substantivity and biocompatibility, serves as an effective adjunct but lacks tissue-dissolving properties and forms harmful precipitates when combined with NaOCl. EDTA, as a chelating agent, is indispensable for removing the inorganic smear layer, improving dentinal tubule permeability, and enhancing sealer adhesion, though prolonged use can weaken dentin. Emerging alternatives, such as herbal irrigants, peracetic acid, and photodynamic therapy, are also discussed as potential solutions to address the limitations of current irrigants. Advances in delivery systems, including passive ultrasonic irrigation and laser-activated irrigation, further enhance the efficacy of these agents. This comprehensive review underscores the importance of selecting and combining irrigants judiciously to optimize root canal disinfection while minimizing adverse effects, contributing to improved clinical outcomes in endodontic practice.