摘要
目的应用三维有限元法研究上颌中切牙不同形态不同材料桩核修复后牙本质内的应力分布。方法通过螺旋CT扫描、Unigraphics(UG)软件建立锥形桩、柱形桩修复的上颌中切牙三维有限元模型,模拟聚乙烯纤维树脂、碳纤维及氧化锆3种不同弹性模量桩核材料,在上颌中切牙舌侧切1/3与中1/3交界处,与牙体长轴成45°切龈向加载,载荷量为100 N,加载方式为静态加载,分析牙本质内的Von Mises应力。结果氧化锆作为桩核材料时,柱形桩牙本质界面应力值显著高于锥形桩(P<0.05);当桩核材料为碳纤维和聚乙烯时,锥形桩与柱形桩之间牙本质界面应力值差异无统计学意义(P>0.05)。随着桩核材料弹性模量的增大,牙本质应力也增大。结论当选择高弹性模量桩核材料时锥形桩优于柱形桩。尽可能选择低弹性模量桩核材料有利于应力分布,防止根折。临床在桩冠根管制备时尽可能地保留根颈1/3处根内牙本质,尤其是唇侧牙本质厚度。
Objective To investigate the stress distribution in dentin of the maxillary central incisor restored with post-core which is related to different shapes and materials.Methods CT scan,digital-image processing and Uni-graphics（UG） software were applied to construct the three-dimensional finite element models of maxillary central incisor restored with cone or column post-core.Based on this model,stress distribution of Von Mises in dentin with three different materials（polyethylene fiber resin,carbon fiber and zirconia） were analyzed respectively.Static loading（100 N） was used on the lingual boundary line between upper-one-third and middle-one-third of maxillary central incisor,the direction of the loading was 45° to the tooth long axis.Results In posts made of zirconia and restored with column post,the stress distribution in dentin was higher than with cone post（P〈0.05）.In posts made of polyethylene fiber resin or carbon fiber,there was no significant difference between the two post shapes（P〉0.05）.The elastic modu-lus of post-core materials affected the stress distribution,and the higher the elastic modulus was,the higher the stress concentrated.Conclusion Cone post excels column post in higher elastic modulus materials.Using the lower elastic modulus materials possibly can avail to the stress distribution and prevent the root breakage.During the root canal preparation,the dentin around the root neck should be conserved as more as possible,especially the dentin in the labial side.
出处
《华西口腔医学杂志》
CAS
CSCD
北大核心
2012年第2期128-132,共5页
West China Journal of Stomatology
关键词
桩核
应力
三维有限元分析
post-core
stress
three-dimensional finite element analysis
