镊铬合金唇挂钩对RootZX根尖定位仪的精确度影响

The influence of accuracy of Root ZX apex locator with Ni-Cr alloy lip hook

目的 分析镊铬合金唇挂钩是否对Root ZX根尖定位仪测量牙齿操作长度准确性造成影响，探讨镊铬合金唇挂钩作为替代品的可能性。方法 选择根尖孔发育完成的临床拔牙病例117例，根管177个，在拔牙前开髓，分别在Root ZX根尖定位仪装配镊铬合金唇挂钩和配套的插入式唇挂钩，两次测量牙齿操作长度，以拔牙后直接测量法结果作为测量的标准，分析不同材料制作的唇挂钩对Root ZX测量值的差异。结果 以直接测量法结果差异小于0.5 mm作为测量准确的标准, 使用配套唇挂钩的Root ZX的准确率为96.05%。使用镊铬合金唇挂钩的Root ZX 的准确率为94.92%，两者测量值间的差异无统计学意义（P ＞0. 05） 。结论 Root ZX测量牙齿操作长度的准确性不受镊铬合金唇挂钩的影 响，镊铬合金唇挂钩可以作为测量仪配套的唇挂钩的替代品。

Objective Analysis of the accuracy of the Root ZX with Ni-Cr alloy lip hook in measuring the root canal working length. Discuss the possibility of alternatives of Ni-Cr alloy lip hook. Methods 177 root canals in 117 extracted teeth with completed apical foramen were selected. Before the extraction, every root canal working length was measured by Root ZX with the original lip hook or Ni-Cr alloy lip hook respectively. Then comparing the results with the direct measurement, the standard, after extraction. Analyzing the differences of the Root ZX measurement with different alloy lip hook. Results With a tolerance level of 0.5 mm, The accuracy of Root ZX with original lip hook resented 96.05%. The accuracy of Root ZX with Ni-Cr alloy lip hook resented 94.92%. There were no statistical differences between original group and Ni-Cr alloy in results（P〉0.05）.Conclusions The accuracy of Root ZX was not influenced by the Ni-Cr alloy lip hook. So The Ni-Cr alloy lip hook can be used as a substitute for original lip hook.