Ludlow J B, Peleaux C P
Dental Diagnostic Sciences Department, University of North Carolina School of Dentistry, Chapel Hill.
Oral Surg Oral Med Oral Pathol. 1994 Feb;77(2):208-15. doi: 10.1016/0030-4220(94)90285-2.
Digital subtraction radiography is a sensitive diagnostic technique that allows detection of subtle calcific changes in the jaws and teeth that would otherwise not be radiographically visible. However, a high failure rate associated with stent-based periapical film-positioning strategies combined with the complexity, expense, and time of image acquisition has limited the clinical utility of this technique. This study compares a new technique that uses film-positioning instruments, laser alignment beams, and a cephalostat with a previously validated method that used film positioners and elastic impression material. Two series of periapical radiographs were taken of six different anatomic areas of six phantoms using both techniques. Film pairs were digitally subtracted twice and analyzed. A paired t test for difference in standard deviation of mean pixel values revealed no difference in repositioning accuracy between the two techniques (p = .68). The new technique eliminates problems that are associated with the use of elastomeric impression materials.
数字减影射线照相术是一种敏感的诊断技术，可检测颌骨和牙齿中细微的钙化变化，否则这些变化在射线照片上是不可见的。然而，基于支架的根尖片定位策略的高失败率，再加上图像采集的复杂性、费用和时间，限制了该技术的临床应用。本研究将一种使用胶片定位仪器、激光对准光束和头颅定位仪的新技术与一种先前验证过的使用胶片定位器和弹性印模材料的方法进行了比较。使用这两种技术对六个模型的六个不同解剖区域拍摄了两组根尖片。对胶片对进行两次数字相减并分析。对平均像素值标准差差异的配对t检验显示，两种技术在重新定位精度上没有差异（p = 0.68）。新技术消除了与使用弹性印模材料相关的问题。
