Postoperative pain after single visit root canal treatment using domestic vs. medical grade sodium hypochlorite: a randomized controlled trial

Abstract

Abstract Background Sodium hypochlorite (NaOCl), the primary endodontic disinfectant, is available in both domestic-grade products and specialized medical-grade formulations. The stability and concentration of domestic-grade products are inconsistent, potentially affecting safety and clinical outcomes. This trial compared the impact of domestic-grade versus medical-grade NaOCl on postoperative pain following endodontic treatment in patients with symptomatic irreversible pulpitis. Methodology Sixty participants with symptomatic irreversible pulpitis in mandibular molars were randomly distributed into two groups (n = 30). Following instrumentation with Edge X7 rotary files, Group A received domestic-grade NaOCl irrigation, while Group B was treated with a medical-grade formulation. Participants recorded pain intensity on an 11-point numerical rating scale (NRS) at 6, 12, 24, 48, and 72 h. Results Domestic-grade NaOCl was associated with significantly higher pain levels at 6 h (median 3 vs. 0; p < 0.05) and 12 h (median 2 vs. 0; p < 0.05) compared to medical-grade NaOCl. No significant differences were observed at 24, 48, or 72 h. Conclusions Domestic bleach caused significantly higher early postoperative pain than medical-grade sodium hypochlorite due to its unstandardized, higher concentration. Standardized medical-grade irrigants are recommended to maximize patient comfort and clinical predictability. Trial Registration The protocol for this prospective, parallel group, double blinded, randomized clinical trial was registered at ClinicalTrials.gov ( https://register.clinicaltrials.gov/ ) on 18/11/2025, registration number (NCT07248189). The trial was retrospectively registered.