Effect of the Simultaneous Working Length Control during Root Canal Preparation on Postoperative Pain

Aim: The aim of this study was to evaluate the effect of simultaneous length control during root canal preparation on postoperative pain compared with separate working length determination and root canal preparation. The design was a parallel-group, randomized, controlled trial with 2 arms. Methods: Forty-four molar teeth were randomly divided into 2 groups (n = 22), a control group (separate length determination and root canal preparation) and a simultaneous length control during root canal preparation group. The following variables were recorded: age; gender; tooth number; preoperative pain on the visual analog scale; pain level on days 1, 3, 5, and 7; and analgesic intake after the procedure and initial/final percussion pain. The data were analyzed with the X-2 test, independent samples t test, and Mann-Whitney U test. Results: The simultaneous length control during root canal preparation group resulted in lower postoperative pain levels on day 1 than did the control group (P <.05). Despite 2 patients' intake of postoperative analgesics in the control group, no patient needed to use postoperative analgesics in the simultaneous length control during root canal preparation group (P>.05). Conclusions: Simultaneous length control during root canal preparation as a nonpharmacologic strategy for reducing postoperative pain is a beneficial technique for preventing postoperative pain.