目的采用体外模型研究 Propex 全自动根尖定位仪在不同环境下定位水平斜行根折位置的准确性。方法选取30颗离体前磨牙，采用金刚砂车针从牙根中下段颊侧面以65°的角度斜向冠方破坏牙根，根管暴露即停止切磨且保证根管断面距根尖8 mm ，建立水平斜行根折体外模型。然后用 Propex 根尖定位仪分别于0．9％生理盐水、3％双氧水、17％乙二胺四乙酸（EDTA）3种条件下测量根折位置。对测量结果采用χ2检验进行统计学分析。结果 Propex 全自动根尖定位仪在0．9％生理盐水、3％双氧水、17％ EDTA 条件下测得的准确率分别是83．33％，86．67％，80．00％，虽然3种液体环境下测得的准确率不同，但这种差异没有统计意义（P ＞0．05）。结论 Propex全自动根尖定位仪能够比较准确定位水平斜行根折的位置，且不受液体环境影响。%Objective To evaluate the accuracy of Propex electronic apex locator in positions of simulated hori -zontal oblique root fractures under various conditions .Methods Thirty premolar teeth with simulated horizontal ob-lique root fractures were selected ,and simulated horizontal incomplete root fracture through the preparation of an ob -lique notch on the buccal root surface approximately 65° with respect to the root axis .The notch was 8 mm from the anatomic apex of the root ,completely exposing the root canal .Propex electronic apex locator was applied to determine the fractures plane of the canals being flooded with three different solutions .The working lengths were also visually measured and compared with the electronic reading by using χ2 test .Results While the canals were flooded with 0 . 9% NaCl ,3% hydrogen peroxide and 17% EDTA ,the ratios of the distance within limits of ± 1 .00 mm were 83 . 33% ,86 .67% and 80 .00% ,respectively .There was no significant difference among the three different solutions (P> 0 .05) .Conclusion Propex could measure the length accurately of coronal root canal segment in teeth ,simulated horizontal oblique root fractures under different solutions and without any influencing .
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