摘要
目的：比较三种桩核系统修复喇叭形根管的牙根修复后的抗折性及其折断模式。
材料与方法：30个完整的上颌中切牙，在根管治疗后，沿釉牙骨质界弧形顶点冠方2mm切除牙冠，将根管上1／3敞开形成喇叭形根管，样本随机分成三组：A组，铸造桩核金属全冠修复；B组，玻璃纤维树脂核全冠修复；C组，成品不锈钢平行螺纹桩树脂核全冠修复。样本固定于MTS810测试机上，与牙体长轴呈135度加载，测试折断强度并观察折断模式。结果采用方差分析。
结果：铸造桩核修复抗折强度最高(763.86±86.38N)，其次是成品螺纹桩树脂核修复(619.91±118.89N)，玻璃纤维树脂核组最小(405.54±111.86N)，统计学分析差异具有显著性。
结论：铸造桩核树脂核修复后抗折强度最高，玻璃纤维树脂核修复最低，但后者折断模式最有利于重新修复，而前者通常无法再行修复。
Objective: To evaluate the fracture resistence of the flared canal teeth restoed with three post-and-core systems.
Materials and methods: A total of 30 recently exacted human maxillary centra incisors were endodontically treated,ampulated partial crown,enlarged the root canal at cervical region and randomly divided into three groups of 10:Group A,cast metal post-and-core and crowned;Group B,grass fiber post combined resin core and crowned;Group C,fabricated parapost and resin core and crowned.Each speciment was mounted on the MTS810 universal test machine and subjected to a load at a 135 degrees angle to the long axis until failure. Results were analyzed statistically with one-way analysis of variance and SNK multiple comparison.
Results: There was a statistically significant difference each other.The cast metal post-and-core group had the highest fracture strength (763.86± 86.38N),followed by the fabricated parapost and resin core group(619.91±118.19N) and grass fiber post combined resin core group had the lowest fracture strength(405.54±111.86N).
Conclusion: According to the study the flared root canal teeth treated with cast metal post-and-core had highest fracture strength, but the fracture model of the grass fiber post and resin core group remained more tooth strcrture and allowed the possibility of repreparation.
引文
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