摘要
目的:基于有限元数值计算方法探讨不同基底瓷厚度对IPS e.max press全瓷冠应力的影响。方法:建立下颌第一磨牙形态试件,基底瓷厚度分别为0.30 mm、0.50 mm、0.75 mm、1.00 mm、1.20 mm五组全瓷冠轴对称的有限元模型,模拟最大咬合力600 N垂直加载于半球形加载头,得出全瓷冠应力分布状态。结果:五组模型应力分布区域相似,全瓷冠最大主应力峰值均位于基底瓷层内,主要集中在加载区下方邻接粘结剂的基底瓷处;饰面瓷的最大主应力峰值主要集中在饰面瓷咬合面与半球形加载头接触的外侧周围;基牙及粘结剂最大主应力峰值均集中在肩台处。全瓷冠压应力峰值主要集中在加载区下方与半球形加载头接触的饰面瓷区域;IPS e.max press全瓷冠的基底瓷厚度对全瓷冠、基底瓷、饰面瓷、基牙及粘结剂的最大主应力均有影响。结论:IPS e.max press全瓷冠在正常咬合力作用下,可以在满足美观的基础上,尽量增加基底瓷厚度,以期增加全瓷冠整体断裂强度,提高使用寿命。
Objective：To investigate the effect of different core thickness on the stress of IPS e.max press crown on the base of finite element method.Method：Axisymmetric finite element models with different core thickness（0.30 mm、0.50 mm、0.75 mm、1.00 mm、1.20 mm,respectively）of all-ceramic crown of mandibular first molar was established.The loaded ball was loaded the biggest bite force of 600 N and it was concluded the stress distribution.Result：five model stress distribution area was similar;The maximum principal stress of all-ceramic which lay to core concentrated in the interface of cement and core under the load area;The maximum principal stress of veneer existed on the surface of the crown,particularly around the places the ball contacted;The maximum principal stress of abute and cement concentrated in the shoulder.The pressure stress of all-ceramic concentrated in the surface of the crown,particularly the places the ball contacted;The thickness of the core ceramic had a significant influence on the resulting stresses in the core、veneer、abutment tooth and cement of this axially loaded crown.Conclusion：Based on the study of finite element model,when the aesthetic requirement met under the normal occlusal force,we should try to increase core ceramic thickness in order to enhance the fracture strength of all-ceramic crown and improve lifetime.
出处
《临床口腔医学杂志》
2013年第1期14-17,共4页
Journal of Clinical Stomatology
