Department of Oral Diagnosis, Piracicaba Dental School, University of Campinas, Avenida Limeira, 901, Piracicaba, São Paulo, 13414-903, Brazil.
Oral Radiology Area, Dental School, Federal University of Mato Grosso do Sul, Campo Grande, Mato Grosso do Sul, Brazil.
Clin Oral Investig. 2021 Apr;25(4):2229-2235. doi: 10.1007/s00784-020-03538-4. Epub 2020 Aug 22.
To evaluate the influence of the tube current and metal artifact reduction (MAR) tool on the diagnosis of vertical root fractures (VRF) in a tooth adjacent to a zirconium implant, in cone-beam computed tomography (CBCT) images.
Thirty single-rooted teeth (15 with VRF and 15 control group) were individually positioned in a mandible, and scanned with the OP300 CBCT unit. Images were acquired using a standardized protocol: 5 × 5 cm field of view, 0.08-mm voxel size, and 90 kVp. Each tooth was scanned with and without a zirconium implant in its vicinity, using different tube currents (4 mA, 8 mA, and 10 mA) and conditions of MAR (enabled × disabled). Diagnostic values were calculated for each protocol, and compared by multi-way analysis of variance.
The ROC curve and sensitivity values did not differ significantly among the tube currents, regardless of the presence of the implant and MAR condition (p > 0.05). There were also no significant differences among the tube currents for the specificity values (p > 0.05); however, the specificity differed significantly between the "with implant" and "without implant" conditions, within the same MAR condition and tube current (p < 0.05). Specificity was significantly lower when the implant was present (p < 0.05).
The presence of a zirconium implant impairs the diagnosis of VRF in teeth adjacent to the artifact-generator material. Neither the tube current nor the MAR tool is effective in improving this diagnostic task. Therefore, in this clinical scenario, the use of the lowest tube current (4 mA), without MAR activation, is recommended.
Considering that the tube current is one of the main factors that influence the radiation dose and image quality in CBCT, and that metal artifacts negatively influence the diagnosis of VRF in areas adjacent to the artifact-generator material, it is important to evaluate the effect of this energetic parameter in the diagnosis of VRF in teeth adjacent to zirconium implants.
评估管电流和金属伪影降低（MAR）工具对邻近氧化锆种植体的牙齿中垂直根折（VRF）诊断的影响，在锥形束 CT（CBCT）图像中。
将 30 颗单根牙（15 颗有 VRF，15 颗对照组）单独放置在下颌骨中，并使用 OP300 CBCT 单元进行扫描。使用标准化协议获取图像：5×5 cm 视野、0.08-mm 体素大小和 90 kVp。每个牙齿在其附近有或没有氧化锆植入物的情况下进行扫描，使用不同的管电流（4 mA、8 mA 和 10 mA）和 MAR 条件（启用×禁用）。为每个协议计算诊断值，并通过多因素方差分析进行比较。
无论是否存在植入物和 MAR 条件，管电流之间的 ROC 曲线和灵敏度值均无显著差异（p＞0.05）。在相同的 MAR 条件和管电流下，管电流之间的特异性值也没有显著差异（p＞0.05）；然而，在相同的 MAR 条件和管电流下，“有植入物”和“无植入物”条件之间的特异性存在显著差异（p＜0.05）。当存在植入物时，特异性显著降低（p＜0.05）。
氧化锆植入物的存在会损害邻近伪影生成材料牙齿 VRF 的诊断。管电流和 MAR 工具都不能有效改善这项诊断任务。因此，在这种临床情况下，建议使用最低的管电流（4 mA），不激活 MAR。
鉴于管电流是影响 CBCT 辐射剂量和图像质量的主要因素之一，并且金属伪影会对邻近伪影生成材料区域的 VRF 诊断产生负面影响，因此评估该能量参数对邻近氧化锆植入物的牙齿 VRF 诊断的影响非常重要。
