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目的探讨数字根尖片在术前评估根管内折断器械取出难度和根管侧穿发生中的应用价值。方法应用分角投照技术拍摄的患牙数字根尖片,对2007年4月至2008年10月于烟台市口腔医院特需门诊就诊接受显微超声取根管内折断器械的病例47例进行分析,分析其折断器械在根管内的位置与折断器械取出成功率和根管侧穿发生率的关系。结果当折断器械位于根尖1/3时,应用显微超声技术取出的成功率和根管侧穿发生率分别为36.84%和52.63%,而器械位于根管冠1/3、中1/3时取出成功率分别为90.00%、88.89%,根管侧穿发生率分别为10.00%、11.11%;当折断器械位于弯曲根管以上或以下时器械取出的成功率分别为88.46%和42.86%,根管侧穿的发生率分别为11.54%和47.62%。结论分角投照数字根尖片在术前分析根管内折断器械取出的成功率和根管侧穿的发生具有较高的参考价值,可作为根管内折断器械病例术前难度评估和预测侧穿发生的常规方法。

Research into application of digital periapical film to preoperative assessment of removing intracanal separated instruments with ultrasonic technique under microscope

Objective To explore the application value of digital periapical film to preoperative assessment of removing intracanal separated instruments. Methods Through analyzing digital periapical films with bisecting angle technique， this paper explored the relationship between intracanal position of separated instruments and the success rate of removing separated instruments or the incidence of root canal perforation. Results The successful rate of removing separated instruments in apical third of root canal was 36.84% and the incidence of root canal perforation was 52.63%;compared with the successful rate and the incidence of root canal perforation for separated instruments in coronal third and middle third of root canals， the difference was statistically significant （P < 0.05）. For those separated instruments below the curve of canal， the successful rate and the incidence of root canal perforation was 42.86%and 47.62%，but for those above curve of canal， the successful rate and the incidence of root canal perforation was 88.46% and 11.54%. Conclusion Digital periapical films with bisecting angle technique have important reference value for preoperative assessment of removing intracanal separated instruments， and can be used as a conventional method for preoperative difficulty assessment and prediction of perforation.