Background <p>Effective root canal disinfection is crucial for successful treatment outcomes, especially in the context of conservative root canal preparation. Thus, this systematic review aimed to compare the disinfection efficacy of the GentleWave (GW) system with other conventional and advanced irrigation activation techniques.</p> Methods <p>A comprehensive electronic search was conducted across PubMed (MEDLINE), Web of Science (all databases), Scopus, ScienceDirect, and Cochrane Library databases. In vitro studies that compare the GW system with other conventional and advanced irrigation techniques in terms of microbiological outcomes (e.g., biofilm, bacterial, lipopolysaccharide (LPS), or lipoteichoic acid (LTA) reduction) and/or smear and debris removal were included based on the eligibility criteria. Due to substantial heterogeneity in study designs, interventions, and outcomes, a narrative synthesis was performed. The risk of bias assessment was done using the QUIN Tool.</p> Results <p>A total of 12 studies met the inclusion criteria. GW was associated with significantly higher reductions in LPS and LTA compared to passive ultrasonic irrigation (PUI). While the majority of studies indicated enhanced biofilm and debris/smear layer removal with GW, some studies demonstrated similar or superior disinfection efficacy for PUI, particularly when the latter was used in conjunction with adequate canal preparation and optimized protocols. Er: YAG lasers resulted in comparable debris removal with GW.</p> Conclusion <p>Although GW shows effective disinfection in the context of conservative canal preparations, its superiority over conventional irrigation systems remains inconsistent across studies due to the heterogeneity in study designs. Methodological limitations and cost considerations further limit definitive clinical interpretation. Further well-designed, standardized in vitro protocols and clinical trials are needed to confirm whether GW yields clinically meaningful advantages and is cost-effective compared with established methods.</p> Trial registration <p>The study protocol was registered in the Open Science Framework (DOI No.: <a href="https://doi.org/10.17605/OSF.IO/AZN3T">https://doi.org/10.17605/OSF.IO/AZN3T</a>).</p>