Post-Endodontic Pain: A Critical Narrative Review of Patient, Procedural and Adjunctive Determinants with Evidence-Based Clinical Recommendations

Abstract

Background: Post-endodontic pain (PEP) is the most common short-term complication of root canal treatment. Evidence on its causes and prevention is spread across many trials and systematic reviews, each examining a single factor. Aim: To critically review and grade the evidence on patient, procedural and adjunctive determinants of PEP, and to translate it into practical recommendations. Methods: A critical narrative review was conducted in line with the SANRA quality criteria. Twenty-eight sources published between 2014 and 2026 were analysed: 17 clinical trials, six systematic reviews with meta-analysis, one systematic review without meta-analysis, one practice-based cohort, one cross-sectional biomarker study, one trial protocol and one narrative review. Each determinant was graded using the Oxford Centre for Evidence-Based Medicine levels of evidence. Findings: PEP was reported in 2.5% to 60% of patients, and 14% of 1,059 patients in a practice-based cohort reported severe pain one week after treatment. Patient factors predicted PEP most consistently: severe preoperative pain, female sex, a history of previous postoperative pain, temporomandibular disorders, fibromyalgia and recent analgesic use increased risk, whereas a draining sinus tract and use of magnification were protective. Among procedural factors, larger apical preparation, maintaining apical patency, sealer extrusion and etidronic acid chelation were associated with more pain. Meta-analyses found no meaningful effect of rotary versus reciprocating instrumentation, sodium hypochlorite versus chlorhexidine, sodium hypochlorite concentration or occlusal reduction. Intracanal cryotherapy, low-level laser therapy and diode laser-activated irrigation reduced pain, but mainly within the first 24–48 hours. Most between-group differences were small and short-lived.