INTRODUCTIONRoot canal irrigation plays a pivotal role in Endodontics, to facilitate instrumentation by lubrication, remove debris, microorganisms, smear layer and prevent apical debris packing. Irrigants exert their effects, by mechanical, chemical and biological actions (1). On the mechanical front, streaming forces are delivered to the canal walls. On the chemical front, the active components exert specific actions on the organic and inorganic debris. On the biological front, the antimicrobial action on the organisms in the canal help inactivate or kill them. Root canals are considered "closed systems" (2) where the fluid dynamics of the irrigant plays a major role in ensuring optimal actions. This "irrigation dynamics" (1) refers to how they flow, penetrate and exchange within the root canal walls. Conventional irrigation methods, at best deliver irrigant just 1mm beyond the needle tip. This may help microbes thrive after treatment in the safe havens of root canals, namely the lateral, accessory canals, fins, isthmii and anastomoses. Hence to improvise the cleansing effectiveness of irrigants and thorough removal of microbes, many activation devices are being used.Activated irrigation may be defined as using a method to agitate and improve the flow of irrigants to the intricacies of root canal system by mechanical or other energy forms. While conventional • Irrigant activation proves to be beneficial, in terms of post-operative pain intensity, debridement and canal & isthmus cleanliness. However, no significant benefit can be proved with the available evidence, for activation in terms of antibacterial effect and long term healing of lesions.
HIGHLIGHTSObjective: Irrigant activation has been claimed to be beneficial in in vitro and clinical studies. This systematic review aims to investigate the clinical efficiency of mechanically activated irrigants and conventional irrigation. Methods: A literature search (PROSPERO registration number: CRD42018112595) was undertaken in PubMed, Cochrane and hand search. The inclusion criteria were clinical trials, in vivo/ex vivo on adult permanent teeth involving an active irrigation device and a control group of conventional irrigation. The exclusion criteria were studies done in vitro, animals and foreign language. Adult patients requiring endodontic treatment of permanent dentition and irrigant activation during the treatment were chosen as the participants and intervention respectively. Results: After removal of duplicates, 89 articles were obtained, and 72 were excluded as they did not meet the selection criteria. 6 devices (EndoVac, EndoActivator, Ultrasonic, MDA (manual dynamic agitation), CUI (Continuous Ultrasonic Irrigation) and PUI (Passive Ultrasonic Irrigation)) and 6 variables of interest (Post-operative pain, periapical healing, antibacterial efficacy, canal and/or isthmus cleanliness, debridement efficacy and delivery up to working length) were evaluated in the 17 included articles. The risk of bias and quality of the selected articles were moderate. Results ...