Protocols to evaluate the antibacterial and irrigation efficacy of new root canal irrigants: A systematic review of ex vivo studies

Introduction: Sodium hypochlorite is known as the standard irrigant for root canal treatment. However, current guidelines emphasize careful use because of risk of soft-tissue injury. Despite the growing interest in alternative irrigants, standardized evaluation methods remain unclear. The aim of this systematic review was to provide a structured overview of current methodological practices and to offer evidence-informed guidance for future ex vivo research. Methods: A systematic search was conducted in PubMed, ScienceDirect, and Web of Science following the PRISMA 2020 guidelines to identify original articles published over the past decade that evaluated root canal irrigants, including their antibacterial properties, using ex vivo models. Results: was the most frequently used strain. Evaluation methods often included colony-forming unit counts from sample eluates, morphological analyses using scanning electron microscopy, and Live/Dead staining. Conclusions: This review reveals that ex vivo research on root canal irrigants focuses on the removal of two critical domains - organic pathological tissue and smear layer, while our results represent the most frequent patterns in antibacterial and cleaning assessments. Considering the reaction mechanisms of irrigants, implementing corresponding cytotoxicity or biocompatibility testing would be desirable to establish evidence-based safety evaluation in future studies.