不同瓷层厚度对全瓷冠内部应力分布规律影响有限元分析  

Three-dimension finite element analysis of the influence of various porcelain thickness on the stress distribution of all-ceramic crowns

作　　者：李冰[1] 武秀萍[1] 吴婷婷[1] 王健[1] 罗晓晋[1] 

机构地区：[1]山西医科大学口腔医院修复科,太原030001

出　　处：《中国实用口腔科杂志》2015年第4期226-228,共3页Chinese Journal of Practical Stomatology

基　　金：山西省卫生计生委科研项目(2014094)

摘　　要：目的探讨不同饰瓷和核心瓷牙合面厚度对双层结构氧化锆全瓷冠内部应力分布规律的影响,为临床修复设计提供依据。方法本研究于2012年3—7月在清华大学计算机教研室进行。利用螺旋CT断层图像,构建上颌第一磨牙氧化锆全瓷冠(核心瓷层和饰瓷层)、黏结剂层、牙体组织、牙根、牙周膜、牙槽骨6部分的三维有限元模型,设计垂直集中载荷600 N的加载方式,观察不同饰瓷牙合面厚度(V)与核心瓷牙合面厚度(C)两因素变化对全瓷冠的最大主应力(S1)分布情况。结果随着饰瓷厚度增加,饰瓷本身的应力先减小后上升,即饰瓷厚度为0.7 mm时,S1为73.20 MPa;厚度升至0.9 mm时,S1下降至54.56 MPa;厚度升至1.7 mm时,S1则上升至60.16 MPa。而随着核心瓷厚度增加,核心瓷的应力在减小,即核心瓷厚度为0.3 mm时,S1为116.40 MPa;厚度升至1.3 mm时,S1下降至4.17 MPa,其应力峰值下降幅度为96.75%。结论对全瓷冠的应力分析,得出双层全瓷冠的V和C范围:0.9 mm≤V≤1.5 mm,C≥0.5mm。这就要求在全瓷冠临床预备过程中,必须留出至少1.4 mm的空间,即为两者最低限之和。Objective To investigate the relationship between various veneer layer occlusal thickness and the core layer ocelusal thickness and stress distribution of two-tier structure all-ceramic crown, and provide the basis for the design of clinical repair. Methods The images of spiral CT were used to construct the finite element analysis model, the model is separated into six parts ： crown （including the core layer and the veneer layer）, agglomerant, prepared tooth , the root of the tooth, periodontal ligament, and alveolar bone, and load way was designed ： 600 N load was vertically concentrated, and ANSYS software was used to analyze the stress values （S1）of two-tier structure all-ceramic crown between various veneer layer occlusal thickness （V）and the thickness of the core layer occlusal（C）. Results With the increase of the thickness of veneer layer, the stress decreased first and then rose with decorated porcelain thickness of 0.7 ram, S1 was 73.20 MPa. When it rose to 0.9 mm, S1 decreased to 54.56 MPa. When thickness rose to 1.7 mm, SI rose up to 60.16 MPa. The stress of the core porcelain decreased with the increase in the thickness of the core porcelain, and when the core porcelain thickness was 0.3 mm, S 1 was 116.40 MPa. When thickness rose to 1.3 mm, the S1 was decreased to 4.17 MPa, the stress peak decreased 96.75%. Conclusion From the stress analysis for all-ceramic crowns, you can know the V and C range of the double-layer all-ceramic crowns： 0.9 mm≤ V ≤ 1.5 ram, C≥0.5 mm. This requires that at least a space of 1.4 mm must be left during the clineal preparation of all-ceramic crowns.

关 键 词：全瓷冠 有限元分析 应力 饰瓷 核心瓷 

分 类 号：R78[医药卫生—口腔医学]