Post-Operative Pain After Endodontic Instrumentation, Irrigation and Obturation: An Umbrella Review of Systematic...

Background: The objective was to synthesize and critically appraise systematic reviews with meta-analysis evaluating the association between irrigation, instrumentation, and obturation procedures and post-operative endodontic pain. Methods: An umbrella review was conducted following PRISMA guidelines. Electronic searches identified systematic reviews published between 2016 and 2025. Eligible studies are systematic reviews that include meta-analyses, published in English and correlating the presence of post-operative pain in 3 different critical stages of root canal treatments, namely irrigation, instrumentation and obturation. Methodological quality was assessed using the AMSTAR 2 tool. Outcomes included pain prevalence and intensity at different time points. Results: Out of 368 records, 25 systematic reviews with meta-analysis met the inclusion criteria: 9 on irrigation, 8 on instrumentation, and 8 on obturation. NaOCl concentrations, irrigant activation, and intracanal cryotherapy were repeatedly reported as being associated with reduced short-term post-operative pain. For instrumentation, most reviews reported lower pain with rotary systems, but two studies found no difference or favored reciprocating kinematics. Apical patency did not appear to increase pain and foraminal enlargement may increase early pain. No clinically consistent differences were observed between bioceramic/calcium silicate-based and resin-based sealers, although calcium silicate sealers seem to support periapical healing. However, the certainty of these findings was limited by heterogeneity, methodological weaknesses, and overlap among primary studies. Methodological limitations were identified across reviews, mainly related to no protocol registration (n = 4), incomplete reporting of excluded studies with justification (n = 11), limited assessment of publication bias, and poor reporting of funding sources for primary studies. Conclusions: Based on current evidence, irrigation, instrumentation, and obturation procedures may influence short-term post-operative pain. However, these findings remain tentative because of heterogeneity, methodological weaknesses, variable review quality, and overlap among primary studies. Further high-quality reviews and clinical trials are needed.