Effect of occlusal reduction on post-endodontic pain in teeth with irreversible pulpitis and symptomatic apical periodontitis: A randomized controlled trial

Background This study evaluated the effect of occlusal reduction (OR) on post-endodontic pain intensity in individuals with carious molars diagnosed as irreversible pulpitis and symptomatic apical periodontitis. Methods This randomized controlled trial included 200 participants (aged 18-44 years), who were randomly allocated to two groups. Preoperative pain score (T0) was recorded on a visual analogue scale (VAS). Group A received occlusal reduction, whereas Group B maintained intact occlusal surfaces. Endodontic treatment was performed over two visits by two experienced endodontists following standard root canal treatment protocols. Postoperative pain was subjectively recorded by using the VAS after the first [(T1 = 6h), (T2 = 12h), (T3 = 24h), (T4 = 48h), (T5 = 72h)] and second visits [(T6 = 6h), (T7 = 24h), (T8 = 48h)]. Statistical analysis was performed using the Mann–Whitney U, Wilcoxon signed-rank, and Friedman tests. Results A total of 180 participants were assessed; pain scores at baseline were comparable between Group A and Group B (median: 8 [IQR: 3] (p = 0.900). Intergroup comparison demonstrated significantly lower pain scores in Group A than in Group B at T1 (p = 0.021), T2 (p = 0.033), and T3 (p = 0.015). However, no statistically significant differences were observed at baseline or from T4 to T8 (p > 0.05). By T4, the median pain score had decreased to zero in both groups and remained negligible throughout the subsequent follow-up period. Conclusion Occlusal reduction significantly provides immediate pain relief up to 24 h after the first visit of root canal treatment in patients presenting with severe pain due to irreversible pulpitis and symptomatic apical periodontitis.