3种桩核系统修复喇叭形根管的抗折性比较

目的 :比较 3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。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 3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°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 (76 3.86± 86 .38)N],其次是成品螺纹桩树脂核修复 (6 19.91± 118.89)N],玻璃纤维树脂核组最小 (40 5 .5 4± 111.86 )N],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。

An in vitro Study of Fracture of Flared Canal Teeth Restored with the Post-and-Core Systems

Objective: To evaluate the fracture resistence of the flared canal teeth restoed with three post-and-core systems. 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: 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 specimen 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 among them. The cast metal post-and-core group had the highest fracture strength \,followed by the fabricated parapost and resin core group\ 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 has highest fracture strength,but the fracture model of the grass fiber post and resin core group remained more tooth structure and allowed the possibility of repreparation.