Department of Dental Materials and Prosthodontics, School of Dentistry of Ribeirao Preto, University of Sao Paulo, Av. Do Café, s/n, Ribeirao Preto, Sao Paulo, 14040-904, Brazil.
Department of Stomatology, Public Oral Health and Forensic Dentistry, Division of Oral Radiology, School of Dentistry of Ribeirao Preto, University of Sao Paulo, Av. Do Café, s/n, Ribeirao Preto, Sao Paulo, 14040-904, Brazil.
Clin Oral Investig. 2021 Aug;25(8):5087-5094. doi: 10.1007/s00784-021-03821-y. Epub 2021 Feb 5.
To evaluate the effect of cone-beam computed tomography (CBCT) tube current (mA) on the magnitude of artefacts at different distances from titanium or zirconia implants, with and without activation of a proprietary metal artefact reduction (MAR).
Human mandibles were scanned on an OP300 Maxio CBCT unit (Instrumentarium, Tuusula, Finland) before and after the installation of dental implants, with four different tube currents (4 mA, 6.3 mA, 8 mA and 10 mA), with and without activation of proprietary MAR. The effect of mA on the standard deviation (SD) of gray values and contrast to noise ratio (CNR) were assessed in regions of interest located 1.5 cm, 2.5 cm, and 3.5 cm from implants.
In the presence of titanium implants, a significant decrease in SD was found by increasing tube current from 4 mA to 6.3 mA or 8 mA. For zirconia implants, 8 mA yielded better results for all distances. MAR improved CNR in the presence of zirconia implants at all distances, whereas no differences were observed with the use of MAR for titanium implants.
Increased tube current can improve overall image quality in the presence of implants, at all the distances tested. When a zirconia implant is present, such increase in mA should be higher in comparison to that for examinations with titanium implants. Activation of OP300 Maxio proprietary MAR improved image quality only among examinations with zirconia implants.
Artefact-generating implants are common in the field of view of CBCT examinations. Optimal exposure parameters, such as tube current, ensure high image quality with lowest possible radiation exposure.
评估锥形束计算机断层扫描（CBCT）管电流（mA）对钛或氧化锆种植体不同距离处伪影程度的影响，同时评估是否激活专有金属伪影降低（MAR）。
在 Instrumentarium 公司的 OP300 Maxio CBCT 设备上对人类下颌骨进行扫描，扫描分为种植体安装前后，使用了 4 种不同的管电流（4mA、6.3mA、8mA 和 10mA），同时评估了是否激活专有 MAR。在距离种植体 1.5cm、2.5cm 和 3.5cm 的感兴趣区域评估 mA 对灰度值标准偏差（SD）和对比噪声比（CNR）的影响。
在存在钛种植体的情况下，管电流从 4mA 增加到 6.3mA 或 8mA 时，SD 显著降低。对于氧化锆种植体，所有距离下 8mA 均产生更好的结果。MAR 在所有距离下均提高了氧化锆种植体存在时的 CNR，而在钛种植体中使用 MAR 则没有观察到差异。
在存在种植体的情况下，增加管电流可以改善整体图像质量，在所有测试距离下均如此。当存在氧化锆种植体时，与钛种植体检查相比，应增加更高的 mA。激活 OP300 Maxio 专有 MAR 仅提高了氧化锆种植体检查的图像质量。
伪影产生的种植体在 CBCT 检查的视野中很常见。优化的曝光参数，如管电流，可以在尽可能低的辐射暴露下获得高质量的图像。
