根管治疗后隐匿性牙根纵裂裂纹宽度对CBCT检出率的影响

目的:探讨裂纹宽度对使用锥形束CT(cone beam CT,CBCT)检测根管治疗后隐匿性牙根纵裂(vertical root fracture,VRF)的影响。方法:收集2016年3月~2019年3月期间26例根管治疗后怀疑隐匿性牙根纵裂患牙,所有患牙均行CBCT扫描并进行术前CBCT评价裂纹有无,所有患牙均因折裂或明显骨吸收拔除,拔除后的离体牙在显微镜下确认裂纹有无,并将拔除后的VRF患牙立即进行micro-CT扫描,使用ImageJ对micro-CT图像检测出的裂纹进行宽度测量。将VRF患牙中CBCT裂纹阳性组和阴性组的裂纹宽度使用t检验比较裂纹宽度的差异。结果:26个患牙拔除后确认24个为VRF患牙,24个患牙共有49条裂纹,CBCT术前诊断VRF患牙11颗,CBCT评价VRF牙的灵敏度为45.83%,特异度为100%,准确率为50%,micro-CT扫描VRF牙检出的准确率为100%,裂纹检出的准确率为95.92%。对micro-CT图像上检测出的裂纹使用ImageJ测量CBCT阴性组的裂纹宽度在15~99μm之间,阳性组的裂纹宽度在62~288μm之间,阳性组和阴性组之间的裂纹宽度具有显著性差异(P<0.05)。结论:根管治疗后隐匿性牙根纵裂牙在体CBCT检测的准确率相对较低,裂纹宽度是影响CBCT检测的重要因素之一。

Influence of Width of Fracture Line on Detection of Subtle Vertical Root Fracture in Endodontically Treated Teeth using Cone Beam CT

Objective:To explore the influence of width of fracture lines on the detection of subtle vertical root fracture(VRF)in endodontically treated teeth using cone beam CT(CBCT).Methods:Twenty-six patients with incredulous VRFs in endodontically treated teeth were collected from March 2016 to March 2019.All patients were performed CBCT scan and evaluated the presence or absence of fracture line.All teeth were extracted due to diagnosis of VRF or severe bone loss.The position of the fracture line was confirmed and recorded under a microscope,and the teeth were immediately subjected to micro-CT scan in vitro,and the ImageJ was used to measure the width of fracture line on micro-CT images.Results:Of 26 teeth,24 teeth were confirmed to be VRFs with 49 fracture lines.11 teeth were diagnosed VRF using CBCT before extraction.The sensitivity,specificity,and accuracy were 45.83%,100%,and 50%.All 24 teeth that were diagnosed as VRF by micro-CT.the accuracy was 100%for diagnosis of VRF teeth and 95.92%for fracture lines.The width of fracture line was between 15μm-99μm in CBCT negative group and 62μm-288μm in CBCT positive group.There was a significant difference of the width of the fracture line between two groups(P<0.05).Conclusion:The accuracy of CBCT detection in subtle vertical root fracture in endodontically treated teeth is relatively poor,and the width is an important factor affecting CBCT diagnosis.