Comparative review of endodontic irrigants: Balancing antimicrobial efficacy, tissue dissolution, and biocompatibility

Introduction: The success of endodontic treatment depends on the effective use of irrigants that eradicate biofilms and improve disinfection, which significantly reduces endodontic failures. Objective: To conduct a comprehensive review of the current scientific literature on the most commonly used irrigating solutions in endodontics, which are sodium hypochlorite (NaOCl), chlorhexidine, saline solution (NaCl), and EDTA, comparing their antimicrobial activity, disinfection capacity, and cytotoxicity. Methodology: A search was conducted in PubMed, Scopus, and Google Scholar using the keywords: “endodontic irrigants,” “sodium hypochlorite,” “chlorhexidine,” “normal saline,” “EDTA,” “antimicrobial activity,” “smear layer removal,” and “cytotoxicity”. Results: The irrigants evaluated showed clear differences in efficacy and clinical function. Sodium hypochlorite obtained the best results in bacterial elimination and tissue dissolution. Chlorhexidine demonstrated good penetration and prolonged residual effect. Saline solution showed low antimicrobial action but excellent biological tolerance. Ethylenediaminetetraacetic acid improved dentin cleaning and enhanced the action of other irrigants, demonstrating its value as a complementary agent in endodontic therapy. Conclusion: Endodontic irrigants perform complementary functions. Sodium hypochlorite is the most effective but also the most cytotoxic. Chlorhexidine offers residual effect and good penetration. Saline solution is biocompatible, although less effective antimicrobially, and ethylenediaminetetraacetic acid improves dentin cleaning. Their appropriate combination balances efficacy and clinical safety.