The aim of this study was to compare the effect of ozone and low-level-laser therapy (LLLT) on postoperative pain after root canal treatment in symptomatic apical periodontitis on vital teeth. Eighty patients were divided into four groups using a web program as follows: LLLT placebo (mock laser therapy), LLLT, Ozone placebo (mock ozonated water irrigation), and Ozone. Postoperative pain levels for 7 days after treatment and percussion pain levels at the 7th day were recorded on the visual analog scale. A regression analysis, Cochran’s Q test, Chi-square test, Kruskal-Wallis tests were performed to analyze the data (P=.05). A regression analysis demonstrated that the most effective variables are “group” and “jaw” (P=0.01). Pain in the lower jaw is higher than the upper jaw. There was difference between the groups on postoperative pain at the days 1, 2, and 3; however, there was no significant difference on other days. LLLT and ozone groups had less postoperative pain and pain on percussion. Low-level laser and ozone therapy are useful methods on postoperative-pain in vital symptomatic teeth ,but they don’t have superiority to each other.

本研究的目的是比较臭氧和低强度激光治疗 (LLLT) 对活牙症状性根尖周炎根管治疗术后疼痛的影响。使用网络程序将 80 名患者分为四组，如下：LLLT 安慰剂（模拟激光治疗）、LLLT、臭氧安慰剂（模拟臭氧水灌溉）和臭氧。用视觉模拟量表记录治疗后7天的术后疼痛水平和第7天的叩击痛水平。进行回归分析、Cochran's Q 检验、卡方检验、Kruskal-Wallis 检验来分析数据（ P =.05）。回归分析表明，最有效的变量是“群体”和“下巴”（ P =0.01）。下颌的疼痛程度高于上颌。术后第1、2、3天各组间疼痛情况存在差异；然而，其他日子没有显着差异。 LLLT 和臭氧组术后疼痛和叩击痛较少。低强度激光和臭氧治疗是治疗有生命症状的牙齿术后疼痛的有效方法，但两者并不具有优越性。