T The use of instruments in endodontic treatment will produce a smear layer thatcovers the root canal walls and dentinal tubules. Root canal irrigation is required to removeorganic and anorganic components from the smear layer inside the root canal. Optimalirrigation is based on the combined use of 2 or more irrigation solutions. Objective: Thisstudy aims to determine the difference in cleanliness in 1/3 of the root canal using a combinedsolution with and without sonic activation. Methods: An experimental study was conductedon 40 mandibular premolars that had been extracted with a single root canal. Preparationswere made to #30.06 with 5% NaOCl and final irrigation using 0.2% Chitosan irrigationsolution or EDTA. Next, groups were divided into two, namely with sonic activation andwithout sonic activation. Root canal cleanliness was assessed using Scanning ElectronMicroscope. The results were analyzed using Kruskal Wallis statistical test and Dwass-Steel-Critchlow-Fligner pairwise comparisons post-hoc test. Results: The results of statisticalanalysis showed that there were significant differences (p>0.05) between the four groups. Thebest cleanliness was seen in the sonic-activated irrigation solution, with no significantdifference between the two irrigation materials. Conclusion : EDTA 17% and Chitosan 0.2%have the same ability to clean the smear layer. The use of sonic activation can maximize theaction of both irrigants.