Post-treatment endodontic pain following occlusal reduction in mandibular posterior teeth with symptomatic irreversible pulpitis and sensitivity to percussion: a single-centre randomized controlled trial.

Abstract

This randomized, prospective, controlled trial assessed the effect of occlusal reduction on post-treatment endodontic pain and medication intake following root canal treatment of mandibular posterior teeth with symptomatic irreversible pulpitis with sensitivity to percussion treated in two visits. Three hundred and eight patients were randomly assigned into two equal groups according to whether occlusal reduction was done or not (n=154). For all patients, root canal treatment was carried out in two visits without intracanal medication. Patients assessed their pain using the 0-10 numerical rating scale (NRS) 6, 12, 24 and 48h after the first visit (post-instrumentation) and 6 and 12h following root canal filling (post-obturation). Patients, also, recorded their medication intake (sham or analgesic), post-instrumentation and post-obturation; patients initially received a sham capsule, but, if pain persisted, an analgesic was prescribed. Data were analysed using Mann-Whitney U-test, Friedman's test, Wilcoxon's rank test and chi-square (χ2 ) test. The relative risk (RR) and its 95% confidence interval (CI) were calculated for binary data. Occlusal reduction was associated with lower pain intensity than no occlusal reduction at 12 and 24h post-instrumentation (P<0.05). Pain intensity significantly and gradually decreased with both groups at all post-instrumentation and post-obturation time-points compared to preoperative pain (P<0.05). The RR of moderate-to-severe pain was 0.61 (95% CI: 0.41, 0.91) 12h post-instrumentation, and the RR of pain incidence, regardless of its level, was 0.75 (95% CI: 0.61, 0.92) 24h post-instrumentation. There was no significant difference in medication intake (sham or analgesic) between groups (P>0.05). Occlusal reduction was effective in reducing the intensity of postoperative pain 12h and 24h after root canal instrumentation in the first visit in patients with symptomatic irreversible pulpitis with sensitivity to percussion. Occlusal reduction lowered the risk of moderate-to-severe pain by about 40% 12h post-instrumentation and the overall risk of pain by 25% 24h post-instrumentation; yet, it did not affect medication intake.