Afkhami Farzaneh, Ghoncheh Zahra, Khadiv Fatemeh, Kaviani Hanieh, Shamshiri Ahmad Reza
Department of Endodontics, School of Dentistry, Tehran University of Medical Sciences, International Campus, Tehran, Iran.
Department of Oral and Maxillofacial Radiology, School of Dentistry, Tehran University of Medical Sciences, International Campus, Tehran, Iran.
Iran Endod J. 2021;16(1):43-48. doi: 10.22037/iej.v16i1.25145.
Our study aimed to assess the diagnostic accuracy of different voxel sizes for cone-beam computed tomography (CBCT) when detecting strip perforations of variable sizes. We used 0.2 and 0.3 mm voxel for detecting root strip perforations.
This was an study conducted on 155 extracted humans' mandibular first molars. The teeth were randomly divided into five groups (=31). Perforation were not induced in the control group. In the remaining four groups, strip perforations of 0.5, 1, 1.5, and 2 mm diameters were created in the mesiolingual canal using #3 Gates Glidden drills. The CBCT scans were taken first with a 12×9 cm field of view (FOV), 90 kVp, 4 mA, and 0.2 mm voxel size for 24 sec and then with a 12×9 cm FOV, 90 kVp, 2 mA, and 0.3 mm voxel size for another 24 sec. Two observers evaluated the images and reported the largest diameter of perforations. The results were compared with the gold standard values (determined by an electronic digital caliper) using statistical methods, including the kappa coefficient and generalized estimating equation (<0.05).
Based on the findings of our study, the inter-observer agreement ranged from 58-100%, while the intra-observer agreement was reported to be around 100%. The difference in accuracy between 0.2 and 0.3 mm voxel sizes was not statistically significant (>0.05). In addition, the accuracy of detecting different perforation sizes in the CBCT did not follow a specific pattern.
This study showed that CBCT is a reliable diagnostic tool, and even in lower dosages of 0.3 mm voxel size, image resolution and diagnostic accuracy was not affected. Moreover, smaller root perforations could be detected as accurately as larger ones with CBCT.
我们的研究旨在评估锥形束计算机断层扫描（CBCT）在检测不同大小的条状穿孔时，不同体素大小的诊断准确性。我们使用0.2毫米和0.3毫米的体素检测牙根条状穿孔。
这是一项对155颗拔除的人类下颌第一磨牙进行的研究。牙齿被随机分为五组（每组n = 31）。对照组不诱导穿孔。在其余四组中，使用#3盖茨-格利登钻在近中舌根管中制作直径为0.5、1、1.5和2毫米的条状穿孔。首先使用12×9厘米视野（FOV）、90千伏峰值、4毫安和0.2毫米体素大小进行24秒的CBCT扫描，然后使用12×9厘米视野、90千伏峰值、2毫安和0.3毫米体素大小再进行24秒的扫描。两名观察者评估图像并报告穿孔的最大直径。使用包括kappa系数和广义估计方程在内的统计方法（P<0.05）将结果与金标准值（由电子数字卡尺确定）进行比较。
根据我们的研究结果，观察者间的一致性范围为58 - 100%，而观察者内的一致性据报道约为100%。0.2毫米和0.3毫米体素大小之间的准确性差异无统计学意义（P>0.05）。此外，CBCT检测不同穿孔大小的准确性没有遵循特定模式。
这项研究表明，CBCT是一种可靠的诊断工具，即使在0.3毫米体素大小的较低剂量下，图像分辨率和诊断准确性也不受影响。此外，CBCT能够同样准确地检测较小的牙根穿孔和较大的牙根穿孔。
