Determining the optimal irrigation activation or agitation techniques for postoperative pain control: A network meta-regression of clinical trials

Postoperative pain after root canal treatment remains a frequent clinical problem despite advances in instruments and irrigants. This Bayesian systematic review and network meta-regression compared seven irrigation activation/agitation techniques-positive pressure, manual dynamic, sonic, ultrasonic, multisonic, negative-pressure and laser-activated irrigation-with respect to Day-1 postoperative pain. Electronic searches of PubMed, Cochrane Library, Scopus and Web of Science were conducted up to 10 December 2024; 57 trials (2595 patients) were included qualitatively and 31 contributed to the quantitative network. Pain scores were rescaled to a 0-10 scale and analysed as mean differences, with symptomatic status modelled as an ordinal covariate and treatment rankings summarised using SUCRA values. Laser-activated irrigation (LAI) produced the lowest Day-1 pain and showed a clinically important advantage over manual dynamic irrigation (MDI) exceeding the 1.0-point minimal clinically important difference, while also outperforming positive pressure and ultrasonic irrigation with smaller, statistically but not clinically important effects. Multisonic and negative-pressure irrigation also ranked favourably, whereas MDI consistently showed the highest pain scores and the lowest SUCRA values. Baseline symptomatic status was a strong effect modifier, with symptomatic teeth experiencing substantially higher pain irrespective of technique. Overall CINeMA confidence was low to very low for most contrasts, indicating that these findings should be interpreted cautiously and highlighting the need for larger, better-designed trials with standardised pain-assessment protocols.