Fava L R
Int Endod J. 1995 Mar;28(2):103-7. doi: 10.1111/j.1365-2591.1995.tb00168.x.
A clinical study was carried out on nonvital maxillary central incisors to evaluate the incidence of postoperative pain following single-visit root canal treatment using three different instrumentation techniques. Ninety teeth from 78 patients whose ages ranged from 14 to 63 years were selected and divided into three groups. Each group (30 teeth) was prepared by a different coronal-to-apical technique using different instrument movement depending upon the technique employed: modified double-flared, crown-downpressureless and balanced force techniques. No difference was observed in the incidence of postoperative pain among the groups.
对无活力的上颌中切牙进行了一项临床研究，以评估使用三种不同根管预备技术进行一次性根管治疗后术后疼痛的发生率。选取了78例年龄在14至63岁之间患者的90颗牙齿，并将其分为三组。每组（30颗牙齿）采用不同的冠向根尖技术进行预备，根据所采用的技术使用不同的器械操作方式：改良双喇叭口技术、冠向下无压力技术和平衡力技术。各组之间术后疼痛的发生率未观察到差异。
