ROLE OF IRRIGANTS IN THE FIELD OF ENDODONTICS - A SYSTEMATIC REVIEW

Abstract

Background: Endodontic irrigation plays a critical role in root canal therapy by aiding in the removal of microorganisms, tissue debris, and the smear layer. Due to the complex anatomy of the root canal system, mechanical instrumentation alone is insufficient, necessitating the use of chemical irrigants to achieve thorough decontamination and cleaning.Objective: This systematic review aims to evaluate the current literature on endodontic irrigants, focusing on their antimicrobial efficacy, biocompatibility, and clinical applications. It provides a comparative analysis of conventional and emerging irrigants, highlighting their advantages, limitations, and potential role in optimizing root canal disinfection.Methods: A systematic search was conducted in PubMed, Scopus, and Web of Science following PRISMA guidelines. Inclusion criteria encompassed peer-reviewed studies published in English between 2017 and 2021, including clinical trials, in vitro, and in vivo studies evaluating antimicrobial efficacy, cytotoxicity, and smear layer removal. Studies without sufficient methodology, case reports, and non-peer-reviewed sources were excluded. Data extraction was performed to assess the type of irrigant, concentration, antimicrobial activity, biocompatibility, and effectiveness in smear layer removal. The risk of bias was assessed using Cochrane guidelines.Results: Sodium hypochlorite (NaOCl) remains the most widely used irrigant due to its strong antimicrobial properties and tissue dissolution capabilities; however, its cytotoxic effects and potential to weaken dentin structure pose limitations. Chlorhexidine (CHX) demonstrates broad-spectrum antimicrobial activity and substantivity but lacks tissue dissolution properties. Ethylenediaminetetraacetic acid (EDTA) effectively removes the smear layer but can cause dentin erosion with excessive use. Alternative bioactive irrigants, such as herbal extracts (e.g., green tea polyphenols, propolis, aloe vera) and nanotechnology-based solutions (e.g., silver nanoparticles, chitosan-based irrigants), show promise in enhancing antimicrobial activity while reducing cytotoxicity. Additionally, advanced irrigation techniques, including ultrasonic and laser activation, improve the efficacy of irrigant penetration and biofilm disruption. Studies indicate that the choice of irrigant and delivery method significantly impacts the success of root canal disinfection and long-term clinical outcomes.Conclusion: The selection of endodontic irrigants should balance antimicrobial efficacy, tissue dissolution, and biocompatibility. While NaOCl remains the gold standard, emerging alternatives and novel irrigation techniques offer potential improvements. Future research should focus on optimizing irrigation protocols to enhance clinical effectiveness while minimizing adverse effects on periapical tissues and dentin integrity.