Abstract
Background: Post-endodontic pain (PEP) is a frequent outcome of root canal treatment and an important determinant of patient satisfaction and clinical decision-making. Although numerous in-vivo studies have evaluated the effects of tooth type, pulp status, anatomy, instrumentation, irrigation, obturation techniques, sealer selection, and operator-related factors, the evidence remains fragmented and sometimes conflicting. This inconsistency largely reflects heterogeneity in study design, pain assessment methods, follow-up intervals, and reporting standards. A scoping review is therefore warranted to map existing evidence and identify research gaps. Methods: A systematic search of PubMed, Scopus, Web of Science, and the Cochrane Library was conducted according to PRISMA-ScR guidelines. Eligible studies included human in-vivo randomized clinical trials, observational studies, and relevant reviews reporting postoperative pain following non-surgical primary root canal treatment or retreatment. In-vitro and animal studies, case reports, conference abstracts, surgical endodontic procedures, pediatric studies, non-English publications, and studies lacking validated pain outcomes were excluded. Data were charted to explore associations between diagnosis, anatomy, procedural protocols, obturation and sealer selection, irrigation strategies, operator factors, and pain assessment methods. Results: PEP was most strongly associated with preoperative pain, symptomatic irreversible pulpitis, molar anatomy, and retreatment complexity. Procedural variables—such as instrumentation kinematics, number of visits, obturation techniques, and irrigant activation—showed no consistent differences when properly executed. Bioceramic sealers were associated with slightly lower early postoperative pain than epoxy-resin sealers, though differences diminished within 48–72 hours. Operator experience and procedural accuracy significantly influenced outcomes. Pain assessment methods varied widely, with inconsistent reporting. Conclusion: PEP is a multifactorial outcome driven primarily by preoperative inflammation, anatomy, and procedural control rather than isolated technical choices. Future studies should emphasize standardized pain assessment, consistent reporting of analgesic use, and well-controlled multicenter trials.