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目的分析冷牙胶侧向加压与热牙胶垂直加压法充填后根管壁应力及其与牙本质裂纹发生的关系。方法选取2011年4—6月于哈尔滨医科大学附属口腔医院口腔外科门诊因正畸需要或牙周病原因新鲜拔除的人完整单根管离体牙40颗，采用冷牙胶侧向加压法、热牙胶垂直加压法分别对单根管前磨牙进行根管充填。应用医学3D图像编辑处理软件提取根管充填后的牙胶形态，通过特定有限元分析软件计算根管壁应力及其位置，并且分别在距离解剖根尖3、6和9mm处通过图像分析软件观察牙胶形态和牙本质裂纹。结果冷牙胶侧向加压法的牙本质裂纹明显多于热牙胶垂直加压法，所产生的根管壁应力也高于热牙胶垂直加压法。结论冷牙胶侧向加压法的根管壁应力高于热牙胶垂直加压法，并且易造成牙本质裂纹。

Analysis of the root canal wall stress after two kinds of root canal filling

Objective To analyze the relationship of two kinds of root canal filling method with the stress of root canal wall. Methods Cold gutta-percha lateral pressure method and warm gutta-percha vertical condensation method were used to fill the single root premolars. Use medical 3D image editing software to extract the gutta-percha morphology. Through a specific finite element analysis software, calculate the root canal wall stress and the stress position. And at 3, 6 and 9 mm from the anatomical apix image analysis software was used to observe gutta-percha morphology and dentine cracks. Results Dentine cracks by cold gutta-percha lateral compression method were significantly more than those by warm gutta-percha vertical condensation method, and the stress of root canal wall was also higher than that of warm gut- ta-percha vertical condensation technique. Conclusion The root canal wall stress by cold gutta-percha lateral compression method is higher than that by warm gutta-percha vertical condensation method, and is likely to cause dentine cracks.