Association between resting-state alpha oscillations and postoperative pain following endodontic treatment

This study evaluated whether preoperative alpha brain wave activity measured using electroencephalography is associated with postoperative pain intensity after single-visit endodontic treatment in patients with symptomatic irreversible pulpitis. One hundred healthy adults with symptomatic irreversible pulpitis in mandibular first molars were included. Preoperative alpha brain wave activity was recorded before treatment. All patients received standardized single-visit root canal treatment. Pain intensity was recorded using a visual analog scale preoperatively and at 6, 24, 48, and 72 h postoperatively. Correlations between alpha power and pain scores were analyzed using Spearman rank-order correlation. Associations with gender and changes in pain over time were also assessed. Postoperative pain decreased significantly from 24 h onward (24 h, p < 0.05; 48 h, p < 0.0001; 72 h, p < 0.0001). Higher preoperative alpha brain wave activity was associated with lower postoperative pain scores. In the overall sample, negative correlations were observed at 6 h (p < 0.05, r = -0.247), 24 h (p < 0.001, r = -0.321), 48 h (p < 0.001, r = -0.321), and 72 h (p < 0.001, r = -0.336), as well as for median postoperative pain scores (p < 0.01, r = -0.309). Females reported higher preoperative pain scores (p < 0.05), but no significant gender differences were observed postoperatively. Subgroup analysis showed variation in the timing of significant correlations between males and females. Preoperative alpha brain wave activity was associated with postoperative pain intensity after root canal treatment. These exploratory findings suggest that resting neural activity may reflect individual variation in pain susceptibility, although the reported p-values are unadjusted for multiple comparisons and require external validation.