Endodontic Irrigation Systems and Techniques: A Review of the Literature

Abstract

Effective irrigation is central to the success of root canal treatment, enabling removal of microorganisms, tissue remnants, and the smear layer from complex root canal systems. Traditional irrigants such as sodium hypochlorite, chlorhexidine, and EDTA remain the foundation of endodontic disinfection, but limitations in their effectiveness and safety have driven the development of newer agents and combinations. Delivery methods have also evolved from conventional syringe irrigation to advanced activation systems, including ultrasonic, sonic, laser-based, negative pressure, and multisonic technologies. Adjuncts such as intracanal heating, surfactants, and microbubble technology are under exploration for improved efficacy. Laboratory evidence strongly supports the superiority of activated and advanced systems in enhancing microbial reduction, smear layer removal, and irrigant penetration. However, translational challenges, methodological variability, and limited long-term clinical evidence restrict definitive conclusions on their impact on treatment outcomes. Future directions require standardized protocols, clinically relevant biofilm models, well-designed randomized controlled trials, and patient-centered outcome measures. This review synthesizes current knowledge, highlights limitations, and discusses future perspectives in the evolving landscape of endodontic irrigation.