2种根尖定位仪准确性的临床评价

目的 评价2种根尖定位仪的准确性。方法 选取因修复需要根管治疗的上前牙，共40个根管。要求未罹患任何牙体牙髓疾病，具有正常牙髓活力。局麻下常规开髓，分别选用第三代电子根管测量仪ROOT ZX及第四代产品VDW Raypex5测量工作长度。随后插针进行牙CT拍摄，从牙CT影像中得到根尖孔位置，测得工作长度，并以此作为金标准。引入经典流行病学中对诊断试验评价的方法，采用SPSS13.0软件，根据测得数据绘制受试者工作特性曲线（receiver operator characteristic curve，简称ROC曲线），按曲线下面积，比较几种诊断试验的诊断效率。结果 ROOT ZX和VDW Raypex5的准确率分别为87.5%和92.5%。ROC曲线下面积ROOT ZX为0.489，VDW Raypex5为0.505。结论 ROOT ZX和VDW两代产品都对根管工作长度的测量结果准确、安全、可靠。ROC曲线是一种全面、准确评价诊断试验有效的方法。

Clinical evaluation of accuracy of two root apex locators

Objective To evaluate the accuracy of two electronic root apex locators under in vivo condition. Methods A total of 40 single-rooted maxillary anterior teeth, with normal pulp vitality and withoutany dental diseases, were selected due to prothedontic needs. The pulp chamber was opened by conventional way under local anesthesia. The working length was measured by third generation of electronic root apex locator ROOT ZX, and forth generation VDW Raypex5. The file was then placed into the root canal for CT scan to obtain the position of root apical foramen. The working length was measured and used as gold standard. Results The accuracy of ROOT ZX and VDW Raypex5 was 87.5% and 92.5%, respectively. With introduction of diagnostic evaluation method of classical epidemiology, the Receiver Operating Characteristic (ROC) curve was drawn by spss13.0 according to measured data, the area under the curve of ROOT ZX and VDW Raypex5 was 0.489 and 0.505, respectively. Conclusion The ROC curve was an effective method for comprehensive, accurate diagnostic evaluation. Both ROOT ZX and VDW electronic root apex locators are accurate, safe and reliable instruments for root canal length measurement. Higher accuracy values were obtained with the VDW Raypex5, but no statistically significant difference was observed (P>0.05).