Department of Therapeutic Dentistry, Federal State Autonomous Educational Institution of Higher Education I.M. Sechenov First Moscow State Medical University (Sechenov University) of the Ministry of Health of the Russian Federation, Moscow, Russia.
Independent X-ray Diagnostic Laboratory, "3D Lab", Bolshaya Andronievskaya, Moscow, Russia.
Dentomaxillofac Radiol. 2019 Sep;48(6):20180327. doi: 10.1259/dmfr.20180327. Epub 2019 May 24.
To compare the accuracy of cone-beam CT and for the detection of artificially created large and small vertical root fractures in extracted teeth restored with post-core.
Individual metal cast post-cores were fixed in the root canals of 50 extracted single-rooted human teeth. In 30 teeth fractures were created by tapping posts with a hammer. The teeth were sterilised in autoclave and embedded into bite-plates made of silicon impression material. Cone-beam CT scanning was performed and . For the scanning, teeth in sterile plastic bags were inserted into the mouths of volunteers. Then the teeth were sectioned with low-speed saw and the widths of the VRFs were measured microscopically. The teeth were distributed into 2 groups in accordance with the measured fractures' widths: large (wider than 180-250 µm) and small (80-150 µm). Five observers assessed the presence of vertical root fractures on axial CBCT slices. Sensitivity, specificity, accuracy and inter examiner agreement were calculated.
The accuracy of cone-beam CT for large and small vertical root fractures detection was 0.56 and 0.40 respectively ( = 0.043). The sensitivity values were 0.53 and 0.27 for large and small vertical root fractures, respectively ( = 0.043). The visualisation of fracture lines was impossible in 90 % of cases, because of low image quality. Inter examiner reliability analysis showed κ values ranging from 0.02 to 0.54.
Fracture width affected the detectability of vertical root fractures by cone-beam CT in teeth with metal cast post-cores. The detectability of root fractures was decreased because of low image quality, making the assessment of sound tooth tissue impossible.
比较锥形束 CT 和 对带桩核修复的离体牙中人工制造的大、小垂直根折的检测准确性。
将单个金属铸造桩核固定在 50 颗离体单根人牙的根管中。在 30 颗牙中，通过用锤子敲击桩核来制造骨折。牙齿在高压灭菌器中消毒，并嵌入硅印模材料制成的咬合板中。进行锥形束 CT 扫描和 。对于 扫描，将无菌塑料袋中的牙齿插入志愿者口中。然后用低速锯将牙齿切开，并在显微镜下测量 VRF 的宽度。根据测量的骨折宽度将牙齿分为 2 组：大（大于 180-250 μm）和小（80-150 μm）。5 名观察者在轴位 CBCT 切片上评估垂直根折的存在情况。计算敏感性、特异性、准确性和观察者间一致性。
锥形束 CT 对大、小垂直根折的检测准确性分别为 0.56 和 0.40（ = 0.043）。大、小垂直根折的敏感性值分别为 0.53 和 0.27（ = 0.043）。由于图像质量低，90%的情况下无法观察到骨折线。观察者间可靠性分析显示 κ 值范围为 0.02 至 0.54。
在带金属铸造桩核的牙齿中，骨折宽度影响锥形束 CT 对垂直根折的检测能力。由于图像质量低，根折的检测能力降低，导致对正常牙体组织的评估变得不可能。
