Effect of Different Concentrations of Sodium Hypochlorite on Post-Operative Pain After Primary Root Canal Treatment in Teeth Diagnosed with Irreversible Pulpitiis

Objective: To assess the impact of varying concentrations of sodium hypochlorite (NaOCl) on postoperative pain after primary root canal treatment in teeth with a diagnosis of irreversible pulpitis. Study Design: Quasi-experimental study. Place and Duration of Study: Department of Operative Dentistry and Endodontics, Armed Forces Institute of Dentistry Rawalpindi, Pakistan, from Mar 2024 to Sep 2024. Methodology: This study included 100 participants (18–49 years) divided into two groups: Group A (low concentration, 2% NaOCl) and Group B (high concentration, 5.25% NaOCl). Standardized Root canal treatment protocols as per American Association of Endodontists were followed, including irrigation with respective NaOCl concentrations during canal preparation. Postoperative pain was evaluated 24 hours after treatment using the Visual Analog Scale (VAS) and classified as mild, moderate, or severe. Results: The study had total of 100 participants divided into two equal groups based on the concentration of sodium hypochlorite (NaOCl) used during root canal treatment. The high-concentration group exhibited significantly higher pain scores [median(IQR): 7.00(5.00-9.00)] compared to the low-concentration group (median(IQR): 5.00(3.00-6.00)]. Severe pain was reported by 66% of participants in the high-concentration group versus 24% in the low-concentration group (p<0.001). The findings indicate a dose-dependent relationship between NaOCl concentration and postoperative pain severity. Conclusion: Higher concentrations of NaOCl (5.25%) lead to significantly increased postoperative pain compared to lower concentrations (2%). These results suggest that using lower NaOCl concentrations can effectively balance antimicrobial efficacy and patient comfort in root canal treatment for irreversible pulpitis. Further multicenter studies are recommended to validate these findings.