Objective: To compare the ability to eliminate debris and open dentinal tubules of different ultrasound irrigation procedures. Study Design: Forty extracted single-rooted human teeth were instrumented with mechanical rotatory instrumentation, and divided into four groups: (n=10) according to the final irrigation technique: group A (control), 2.5% NaOCl irrigation with the Miraject needle and no ultrasonic agitation; group B, passive ultrasonic irrigation (PUI) with 2.5% NaOCl and Irrisafe 20 tips; group C, PUI with 2.5% NaOCl and Irrisafe 25 tips; group D, PUI with 2.5% NaOCl and K 25 tips. The amount of debris and the number of opened dentinal tubules was established by scanning electronic microscope. Data were compared using the Kruskal Wallis test. Results: Irrisafe tips (groups B and C) opened up more dentinal tubules and eliminated more debris than conventional irrigation (p<0.05) in the apical third. The middle third shows no significant differences between groups. Irrisafe 25 was more effective than conventional irrigation and K tips (p<0.05) in the coronal third. Conclusions: Ultrasonic activation of the irrigation with Irrisafe tips was the most effective procedure for eliminating the debris and opening up dentinal tubules, especially in the apical third.