根管长度电测法准确性及其影响因素的探讨

目的:探讨JUSTY-Ⅱ电测仪测量根管工作长度的准确性及其影响因素。方法:选择148颗患牙,其中牙髓炎71颗,牙髓坏死46颗,根尖周炎31颗。随机分为2组,分别用指感法和电测法测量根管工作长度,以X线片影像为参照,用χ2检验比较其结果,并分析各临床病变类型、根管干湿状态和根管扩大等因素对电测法准确性的影响。结果:电测法准确率为87.84%,指感法为43.24%,2组有高度显著性差异(P<0.01)。根尖周炎组准确率与牙髓炎组、牙髓坏死组有显著性差异(P<0.05)。根管干湿状态对测量结果无影响,扩根前后准确率有显著性差异(P<0.05)。结论:电测法是一种准确、操作简便的测量根管工作长度的方法。根尖周组织的炎症以及根管扩大,均会降低其准确性。

A study on the accuracy of electronic root canal length measurement and its influential factors

PURPOSE: To study the accuracy of JUSTY-II electronic apex locator and the influential factors on the accuracy of root canal working length measurement. METHODS: 148 teeth, including 71 teeth with pulpitis, 46 with necrotic pulp and 31 with apical periodontitis, were divided into two groups in random. The accuracy of electronic root canal working length measurement group was compared with that of the manual measurement group by Chi(2) test. The influence of clinical types, root canal in dry or moisture conditions and root canal preparation on the accuracy of root canal working length measurement was analyzed. RESULTS: The accuracy of electronic apex locator was 87.84%, while it was 43.24% in manual measurement, the difference was significant (P<0.01). The accuracy in the group of apical periodontitis was significantly lower than that of the other groups (P<0.05). Root canal in dry or moisture conditions had no effect on the accuracy of root canal length measurement, but root canal preparation could decrease the accuracy of measurement (P<0.05). CONCLUSION: Electronic apex locator is an accurate and convenient device in measurement of root canal working length. Apical periodontitis and root canal preparation can decrease the accuracy of measurement.