Influence of Laser-Activated vs Ultrasonic Irrigation on Postoperative Pain Following Root Canal Treatment - A Systematic Review

Objective: This systematic review intended to compare the influence of “laser-activated irrigation (LAI)” and “ultrasonic irrigation (UI)” on postoperative pain following root canal treatment in human subjects. Materials and Methods: A comprehensive literature search was conducted in PubMed, Scopus, Cochrane Library, and Web of Science up to April 2025. “Randomized clinical trials (RCTs)” comparing LAI and UI in terms of postoperative pain outcomes were included. Studies evaluating pain using validated scales such as the “Visual Analog Scale (VAS)” within the first seven days post-treatment were considered. Results: Seven RCTs met the inclusion criteria. Most studies demonstrated that LAI, particularly using Er: YAG-based techniques (e.g. Photon-Induced Photoacoustic Streaming [PIPS], Shock Wave Enhanced Emission Photoacoustic Streaming [SWEEPS]), resulted in significantly lower postoperative pain during the first 24–48 h compared with UI. However, pain levels between the groups generally equalized by 72 h. Analgesic consumption was comparable in both groups across most studies. Conclusion: LAI may offer a modest advantage over ultrasonic activation in reducing early postoperative pain after root canal therapy. Both methods, however, are effective and superior to conventional irrigation in pain reduction.