Negm M M
Oral Surg Oral Med Oral Pathol. 1983 Oct;56(4):415-20. doi: 10.1016/0030-4220(83)90353-5.
A new instrument (the Apexfinder) for measuring tooth length was recently introduced for use in endodontics. The procedure of measuring tooth length with this instrument was found to be simple and easy. It also eliminated the need for radiographs, with their problems. One hundred forty-two teeth were used to compare the new method with two different methods, widely used in endodontics, that employ radiographs. The investigation showed that the new technique offers a direct method for measuring the distance between the coronal and apical ends of the tooth. Statistical analysis of the data indicated that the new method was superior to the others. The Apexfinder was accurate in 90 percent of the cases. When radiographs were used, the results were accurate in 75 percent of the cases, while the use of the radiograph and the tooth-length formula gave 60.4 percent accuracy.
最近有一种用于测量牙齿长度的新仪器（根尖定位仪）被引入牙髓病学领域。用这种仪器测量牙齿长度的操作过程被发现简单易行。它还消除了使用X光片时所存在的问题。使用142颗牙齿将这种新方法与牙髓病学中广泛使用的两种使用X光片的不同方法进行了比较。调查表明，这项新技术提供了一种直接测量牙齿冠端和根尖端之间距离的方法。对数据的统计分析表明，新方法优于其他方法。根尖定位仪在90%的病例中是准确的。使用X光片时，结果在75%的病例中是准确的，而同时使用X光片和牙齿长度公式时准确率为60.4%。
