AIM 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. METHODOLOGY 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 48 h after the first visit (post-instrumentation) and 6 and 12 h 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. RESULTS Occlusal reduction was associated with lower pain intensity than no occlusal reduction at 12 and 24 h 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) 12 h post-instrumentation, and the RR of pain incidence, regardless of its level, was 0.75 (95% CI: 0.61, 0.92) 24 h post-instrumentation. There was no significant difference in medication intake (sham or analgesic) between groups (P > 0.05). CONCLUSIONS Occlusal reduction was effective in reducing the intensity of postoperative pain 12 h and 24 h 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% 12 h post-instrumentation and the overall risk of pain by 25% 24 h post-instrumentation; yet, it did not affect medication intake.

中文翻译：

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下颌后牙咬合减少并伴有症状的不可逆性牙髓炎和对cus击的敏感性的治疗后牙髓痛：单中心随机对照试验。

目的这项随机，前瞻性，对照试验评估了咬合减少对有症状的不可逆性牙髓炎根管治疗下颌后牙根管治疗后牙髓痛和药物摄入的影响，两次访视对敲击敏感。方法根据是否进行了咬合复位，将308位患者随机分为两组（n = 154）。对于所有患者，均在两次就诊过程中进行了根管治疗，而未进行腔内药物治疗。患者在首次就诊后（仪表化后），根管充填后6小时和12小时（仪表化后），术后6h，12小时，24小时和48小时使用0-10数字评分表（NRS）评估疼痛。患者还记录了他们的药物摄入量（假或镇痛剂），仪器后和闭孔；患者最初接受了假胶囊，但如果疼痛持续存在，则应开止痛药。使用Mann-Whitney U检验，Friedman检验，Wilcoxon秩检验和卡方（χ2）检验分析数据。针对二进制数据计算了相对风险（RR）及其95％置信区间（CI）。结果在器械植入后12和24小时，与没有咬合减轻相比，减少咬合与降低疼痛强度有关（P <0.05）。与术前疼痛相比，两组在所有器械后和阻塞后的时间点疼痛强度均显着并逐渐降低（P <0.05）。仪器使用后12小时，中度至重度疼痛的RR为0.61（95％CI：0.41，0.91），无论疼痛程度如何，疼痛发生率RR为0.75（95％CI：0.61，0。92）仪器后24小时。两组之间的药物摄入量（假或镇痛剂）无显着差异（P> 0.05）。结论对于有症状且不可逆性牙髓炎的患者，在首次就诊时，减少根管闭合可有效减轻术后根管手术后12 h和24 h的疼痛程度。减少牙合会在器械后12小时降低中度至重度疼痛的风险，降低约40％，在器械后24小时降低总体疼痛的风险25％。然而，它并没有影响药物的摄入。结论对于有症状且不可逆性牙髓炎的患者，在首次就诊时，减少根管闭合可有效减轻术后根管手术后12 h和24 h的疼痛程度。减少牙合会在器械后12小时降低中度至重度疼痛的风险，降低约40％，在器械后24小时降低总体疼痛的风险25％。然而，它并没有影响药物的摄入。结论对于有症状且不可逆性牙髓炎的患者，在首次就诊时，减少根管闭合可有效减轻术后根管手术后12 h和24 h的疼痛程度。减少牙合会在器械后12小时内将中度至重度疼痛的风险降低约40％，在器械后24小时内将总体疼痛的风险降低25％。然而，它并没有影响药物的摄入。