Abstract: Objective    To evaluate the root canal disinfection effect of ultrasonic，sonic and laser-assisted root canal irrigation by in vitro root canal infection model. Methods    A total of 48 single straight root canal anterior teeth extracted due to periodontitis in the oral surgery clinic of the Stomatological Hospital of the Fourth Military Medical University from February to April 2021 were selected，and 3 teeth were randomly selected to confirm the root canal sterilization treatment. Then，Enterococcus faecalis was inoculated and cultured for 4 weeks to construct an in vitro root canal infection model，and 5 teeth were randomly selected for confirmation. After root canal preparation，the remaining 40 teeth were randomly divided into 5 groups with 8 teeth in each group. According to the root canal irrigation methods，they were recorded as follows：ultrasound + irrigation agent group，EDDY + irrigation agent group，laser + irrigation agent group，lateral irrigation needle + irrigation agent group and lateral irrigation needle + normal saline group. The decontamination effect and sterilization effect of each group were observed by scanning electron microscope and laser confocal microscope. Results    The removal effect of smear layer from strong to weak was as follows：EDDY+ irrigation agent group > laser + irrigation agent group > ultrasound + irrigation agent group > lateral needle + irrigation agent group > lateral irrigation needle + normal saline group. The order of sterilization effect from strong to weak was：laser + irrigation agent group > EDDY + irrigation agent group > ultrasound + irrigation agent group > lateral irrigation needle + irrigation agent group > lateral irrigation needle + normal saline group. There was no significant difference in removal effect score and sterilization rate between ultrasound + irrigation agent group and lateral irrigation needle + irrigation agent group（P > 0.05）. There were significant differences among other groups（P < 0.05）. Conclusion    Laser and EDDY-assisted root canal irrigation technology has good root canal disinfection effect，in which the root canal sterilization effect of laser is the most obvious，and the smear layer removal effect of EDDY is the best.

Key words: root canal irrigation, sodium hypochlorite, ethylene diamine tetraacetic acid, EDTA, sonic-activated irrigation, ultrasonic-activated irrigation, laser-activated irrigation, Er∶YAG laser, EDDY, root canal infection model

摘要： 目的    通过体外根管感染模型评估超声、声波、激光辅助根管冲洗技术的根管消毒效果。方法    选择2021年2—4月于第四军医大学口腔医院口腔外科门诊因重度牙周炎拔除的48颗单直根管前牙并进行灭菌处理，随机抽取3颗离体牙对根管灭菌处理进行确认；而后接种粪肠球菌并培养4周以构建体外根管感染模型，并随机抽取5颗离体牙进行确认。将余下的40颗离体牙根管预备后随机分为5组，每组8颗。根据根管冲洗方法分别记为：超声+冲洗剂组、EDDY声波+冲洗剂组、激光+冲洗剂组、侧方冲洗针头+冲洗剂组及侧方冲洗针头+生理盐水组。通过扫描电子显微镜和激光共聚焦显微镜观察各组玷污层清除效果和杀菌效果。结果    玷污层清除效果从强到弱依次为：EDDY声波+冲洗剂组>激光+冲洗剂组>超声+冲洗剂组>侧方冲洗针头+冲洗剂组>侧方冲洗针头+生理盐水组；杀菌效果从强到弱依次为：激光+冲洗剂组> EDDY声波+冲洗剂组>超声+冲洗剂组>侧方冲洗针头+冲洗剂组>侧方冲洗针头+生理盐水组。其中超声+冲洗剂组与侧方冲洗针头+冲洗剂组清除效果评分和杀菌率比较，差异均无统计学意义（均P > 0.05）；其他组间比较，差异均有统计学意义（均P < 0.05）。结论    激光和EDDY声波辅助根管冲洗技术具有较好的根管消毒效果，其中激光的根管杀菌效果较明显，EDDY声波的玷污层清除效果较佳。

关键词: 根管冲洗, 次氯酸钠, 乙二胺四乙酸, 声波荡洗, 超声活化冲洗, 激光活化冲洗, Er∶YAG激光, EDDY声波, 根管感染模型