Novel laser activated photoacoustic streaming for removing pulp remnants from round root canals after single file reciprocating instrumentation

Background: : This study evaluated the efficacy of a new laser-assisted irrigation system, the shock wave enhanced emission photo-acoustic streaming (SWEEPS) technique in removing pulp tissue from single-rooted premolars Methods: : Freshly extracted mandibular premolars with round root canals (n = 40), scanned using cone beam computed tomography, were randomly divided into control and four experimental (according to the irrigation technique used) groups (n = 8/group). Groups 1, 2, and 3 were instrumented using Reciproc Blue (RB25/0.06) followed by final irrigation protocol (FIP), activated by SWEEPS, ultrasonically activated irrigation (UAI), and conventional irrigation (CI), respectively. In these groups, 7 mL 3% NaOCl in total was used during instrumentation; for FIP, 3% NaOCl (60 s), ethylenediaminotetraacetic acid (60 s), and 3% NaOCl (30 s). In group 4, SWEEPS activation of 3% NaOCl for 6 x 30 s alone was performed. The untreated control group specimens were processed for histological evaluation of remaining pulp tissue (RPT) in each canal third. The results were analyzed using the Mann-Whitney U test (alpha = 0.05). Results: : Significant differences were observed between the control group and the experimental groups (p < 0.05). In the middle third, the UIA and SWEEPS showed similar efficacy (p = 0.171), superior to CI and SWEEPS without instrumentation (p < 0.05). In the apical third, SWEEPS was the most efficient (p = 0.002), and UIA and CI showed no difference (p = 0.643). Conclusion: : SWEEPS was superior to UIA and CI in removing RPT in the apical region of round canals after single instrument root canal preparation; SWEEPS without instrumentation was inefficient in removing pulp tissue.