Introduction: Different irrigation systems have been developed to improve the efficacy and distribution of the irrigants. The aim of this study was to compare the effect of conventional endodontic needle irrigation with other irrigant delivery and/or agitation systems on sealer penetration into dentinal tubules. Methods: Fifty single-rooted teeth with round-shaped root canals were distributed in 5 homogeneous groups character- ized by the different cleansing system used: conven- tional endodontic needle irrigation, EndoActivator, Irrisafe, Self-Adjusting File, and EndoVac. After instru- mentation, all teeth were filled by Thermafil obturators and rhodamine B dye labeled TopSeal sealer. Teeth were transversally sectioned at 2-, 5-, and 7-mm levels from the apex and observed under confocal laser scanning microscope. Maximum, mean, and percentage of sealer penetration inside tubules around the root canal were measured. Moreover, the integrity of the sealer layer perimeter was evaluated. Results: No significant differ- ences both in mean (p > .05) and in maximum penetra- tion depth (p > .05) were observed among groups, whereas both parameters showed an increased trend within each group from the 2- to the 7-mm level from apex. Similarly, the percentage of penetration around the root canal wall did not differ among groups (p > .05) and showed an increasing trend within each group from the apical to the coronal portion of the canal. Conclusions: Sealer penetration into dentinal tubules is not affected by the irrigant delivery and/or agitation sys- tems studied. Thermafil with TopSeal technique achieves complete sealer perimeter integrity in all groups.