Rudolph D J, White S C
Section of Oral Radiology, UCLA School of Dentistry.
Oral Surg Oral Med Oral Pathol. 1988 Jun;65(6):767-72. doi: 10.1016/0030-4220(88)90027-8.
Clinical application of digital subtraction radiography is limited by the reproducibility in the orientation of the x-ray source, image receptor, and object. In this study, eight dental intraoral film alignment instruments (including five replicates of each) were tested for accuracy in repositioning over a period of 6 months. Each instrument was made by adhering one of six impression materials (including acrylics, compounds, and elastics) onto the bite blocks of commercially available alignment instruments. The dimensional accuracy and reproducibility of the orientation of the x-ray source with respect to the object were determined over time for each instrument by measuring the horizontal and vertical angulation change in the position of a buccally placed marker on a dried mandible with a lingually placed film grid. Nine measurements were made during the 6-month test period. The most reproducible instrument was the combination of Regisil, an elastic impression material, and a Rinn XCP bite block. This combination yielded a mean absolute horizontal angulation error of 1.34 degrees +/- 0.63 and a mean absolute vertical angulation error of 2.04 degrees +/- 0.82, yielding a total angulation error of 2.44 degrees +/- 1.16. This was within the acceptable range of accuracy needed to produce diagnostically useful information when digital subtraction radiography is used.
数字减影放射成像的临床应用受到X射线源、图像接收器和物体定位重复性的限制。在本研究中，对8种口腔内牙片对准器械（每种包括5个复制品）进行了为期6个月的重新定位准确性测试。每种器械是通过将6种印模材料（包括丙烯酸类、复合物和弹性体）之一粘贴到市售对准器械的咬块上制成的。通过用舌侧放置的胶片格栅测量干燥下颌骨上颊侧放置的标记物位置的水平和垂直角度变化，随时间确定每种器械的X射线源相对于物体的尺寸准确性和定位重复性。在6个月的测试期内进行了9次测量。最具重复性的器械是弹性印模材料Regisil与Rinn XCP咬块的组合。这种组合产生的平均绝对水平角度误差为1.34度±0.63，平均绝对垂直角度误差为2.04度±0.82，总角度误差为2.44度±1.16。当使用数字减影放射成像时，这在产生诊断有用信息所需的可接受准确性范围内。
