Stimmelmayr Michael, Denk Katharina, Erdelt Kurt, Krennmair Gerald, Mansour Sonia, Beuer Florian, Güth Jan-Frederik
Int J Comput Dent. 2017;20(1):21-34.
To measure the deviations of four different cone beam computed tomography (CBCT) devices in three dimensions by means of a three-dimensional (3D) implant-planning program.
A master radiographic template with two vertical, two transverse, and two sagittal radiopaque markers was fabricated for a human dry skull. The lengths of the markers were measured with a high-precision caliper. The skull and the template were scanned in each of the four CBCT devices (1. Gendex GXCB-500; 2. Sirona Galileos Comfort; 3. Sirona Orthophos XG 3D; 4. Carestream CS 9300) 19 times (10 scans without moving the skull, and 9 scans with repeated repositioning of the skull in the device, according to the manufacturers' instructions). A 3D implant-planning program was used to measure the lengths of the six markers digitally. Actual and digital measurements were compared to determine device-specific errors. The repositioning of the skull examined the reproducibility of the CBCT devices. Linear measurements were analyzed statistically (P < 0.05).
RESULTS: Mean deviations without moving the skull (vertical/sagittal/transverse) for device 1 were 0.023 mm/ 0.000 mm/0.025 mm (0.07%/0.19%/0.24%), for device 2 were 0.410 mm/0.115 mm/0.080 mm (-1.75%/0.32%/ 0.88%), for device 3 were -0.665 mm/-0.215 mm/ -0.675 mm (-2.71%/-1.82%/-4.42%), and for device 4 were -0.045 mm/-0.135 mm/-0.410 mm (-0.45%/ -1.54%/-2.57%). The overall mean deviation for device 1 was 0.028 mm (0.16%), for device 2 was 0.072 mm (-0.95%), for device 3 was 0.518 mm (-2.97%), and for device 4 was -0.197 mm (-1.53%). The mean deviation after repositioning for device 1 was 0.004 mm (-0.65%), for device 2 was -0.250 mm (0.95%), for device 3 was 0.496 mm (-2.66%), and for device 4 was -0.265 mm (-1.92%). Thus, apart from device 3, the deviations increased.
Deviations from the actual measurements were detected with each device. Therefore, respecting safety distances when placing implants is crucial.
通过三维种植计划程序测量四种不同锥形束计算机断层扫描（CBCT）设备在三维空间中的偏差。
为一个人类干燥颅骨制作了一个带有两个垂直、两个横向和两个矢状不透射线标记物的主射线照相模板。用高精度卡尺测量标记物的长度。将颅骨和模板在四种CBCT设备（1. 杰登GXCB - 500；2. 西诺德伽利略舒适型；3. 西诺德口腔全景X射线三维成像系统；4. 柯达CS 9300）中各扫描19次（10次扫描时颅骨不移动，9次扫描时根据制造商说明在设备中对颅骨进行重复重新定位）。使用三维种植计划程序对六个标记物的长度进行数字测量。比较实际测量值和数字测量值以确定特定设备的误差。颅骨的重新定位检查了CBCT设备的可重复性。对线性测量值进行统计学分析（P < 0.05）。
设备1在颅骨不移动时的平均偏差（垂直/矢状/横向）为0.023毫米/0.000毫米/0.025毫米（0.07%/0.19%/0.24%），设备2为0.410毫米/0.115毫米/0.080毫米（ - 1.75%/0.32%/0.88%），设备3为 - 0.665毫米/ - 0.215毫米/ - 0.675毫米（ - 2.71%/ - 1.82%/ - 4.42%），设备4为 - 0.045毫米/ - 0.135毫米/ - 0.410毫米（ - 0.45%/ - 1.54%/ - 2.57%）。设备1的总体平均偏差为0.028毫米（0.16%），设备2为0.072毫米（ - 0.95%），设备3为0.518毫米（ - 2.97%），设备4为 - 0.197毫米（ - 1.53%）。重新定位后设备1的平均偏差为0.004毫米（ - 0.65%），设备2为 - 0.250毫米（0.95%），设备3为0.496毫米（ - 2.66%），设备4为 - 0.265毫米（ - 1.92%）。因此，除设备3外，偏差增大。
每种设备均检测到与实际测量值的偏差。因此，植入物放置时考虑安全距离至关重要。
