目的：比较无孔托盘和有孔托盘印模精确度的差异。方法：有孔托盘和无孔托盘分别用二次印模法和一次印模法印取同一主模型，放大镜下观察分析两种托盘在牙冠颈缘复制精确度上的差异。灌制模型，测量模型标志点间的距离，比较两种托盘所取印模模型线性变化。结果：在牙冠颈缘精度上比较，一次印模法无孔托盘优秀率高于有孔托盘，差异具有统计学意义( P <0.05)。在模型线性变化率上比较，两种托盘差异无统计学意义。结论无孔托盘在牙冠颈缘复制上效果优于有孔托盘。%Objective:To compare the accuracy impression between the trays with holes and those without holes. Methods: A tray without holes and a tray with holes were used to make the same master model by one-step and two-step impression methods respectively. The accuracy difference at the cervical margin of the crown was observed and analyzed through a magnifying glass. Models were made, the distance between points was measured and the linear change of the models made by these two types of trays was compared. Results:As for the accuracy at the cervical margin of the crown , the excellent rate of trays without holes is always higher than those with holes, whether the one-step impression method or the two-step impression method was used, but the difference was significant only when one-step impression method was used. As for the linear change rate, the difference between the two kinds of trays was not significant. Conclusion:The copy made at the cervical margin of the crown by Trays without holes is better than that made by trays with holes.
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