Objective: This study evaluated the effectiveness of Diode laser (980 nm) activated irrigation to passive ultrasonic irrigation and traditional irrigation needles for smear layer eradication.
Methodology: To achieve a uniform length of 16 mm, 45 extracted permanent single-rooted mandibular premolars were disinfected and decoronated. After sealing the apices with flowable composite and impeding them in epoxy resin blocks, all teeth were mechanically prepared with ProTaper Next rotary files up to X4. NaOCl was utilized as an irrigant in between each file. According to the activation method, samples were randomly assigned to one of three groups (n=15): Group 1 (DL): a 980 nm Diode laser coupled with an optical fiber of 200 μm; Group 2 (PUI): passive ultrasonic irrigation; and Group 3 (CG): a conventional irrigation protocol without activation (Control group).
Results: There was a significant difference between the three groups in coronal middle and apical thirds (p = 0.01, p Conclusion: DL demonstrated excellent cleaning effectiveness at all root-canal sections that was comparable to PUI. However, no activation approach was able to completely remove the smear layer.