摘要
目的:对垂直静态载荷下模拟天然牙齿与镍铬合金、金钯合金带桩嵌体的等效应力云图进行比较,应用三维有限元法分析带桩嵌体修复下颌磨牙残冠的的等效应力分布。方法:实验于2003-11/2004-12在华南理工大学交通学院应用力学系完成。从6颗离体的形态正常的人右下颌第一磨牙中,选取密合度最好且形态接近临床要求的1颗,应用螺旋CT断层扫描技术和图像合成软件,建立模拟的下颌第一磨牙和带桩嵌体修复的下颌第一磨牙残冠的三维有限元模型。在垂直向加载的情况下,应用三维有限元分析软件分别对天然牙、镍铬合金、金钯合金带桩嵌体修复牙的应力进行分析。结果:从6颗右下颌第一磨牙中选取1颗建立三维有限元模型。①等效应力云图显示,在垂直向加载的情况下,镍铬合金、金钯合金带桩嵌体修复后剩余牙体的各个部位的应力均比模拟天然牙小,应力比较集中在远中牙颈周围,尤其是在牙根内侧,并且颊侧比舌侧受到的等效应力稍大。②将修复后的牙冠及剩余牙体的最大应力进行比较,在100N的垂直荷载下,用合金带桩嵌体修复技术修复牙体的受力情况比完整牙体效果好,且镍铬合金比金钯合金优越一些。结论:垂直向静态载荷下,合金带桩嵌体使修复后的下颌第一磨牙残冠等效应力降低,但等效应力相对集中于远中牙颈,尤其是牙根内侧的颊侧处,且镍铬合金比金钯合金优越一些。提示对固位形比较差的牙体缺损应通过全冠修复或带桩嵌体修复的形式予以治疗。
AIM： In the condition of vertical dead load, modeling natural teeth compares with von-mises stress of post inlay of nichrome and rhotanium, threedimension finite element method is applied to analyze the von-mises stress distribution of post inlay restoration for residual crown of lowers jaw molar. METHODS： The experiment was done from November 2003 to December 2004 in the Department of Applied Mechanics, Communication College, South China University of Technology. From the first molar of the right lower jaw of a eumorphism people with 6 exsomatize, one was selected with the best obturation and the form closed to the clinical requirement. Using spiral CT scanning technique and imaging synthetic software, the three-dimension finite element model of lower jaw first molar and post inlay restoration for residual crown of lowers first molar was established. Under the vertical loading condition, using three-dimension finite element analysis software investigated the stress of natural tooth, nichrome and rhotanium post inlay restoration teeth. RESULTS： One was selected from the first molar of 6 right lower jaws to establish three-dimension finite element model.①Von-mises stress distribution showed that in the vertical loading condition, the stress of each part of the residual tooth restored by the nichrome and rhotanium post inlay was lower than that of the analogous natural tooth. The stress was focused in the around of distal neck of tooth, especially in the inside of root of tooth, and the von-mises stress was bigger of buccal side than that of lingua side. ②The maximum stress of crown after plerosis and rest teeth was compared. Under 100N vertical loading, the restoration receiving power condition of tooth using alloy post inlay restoration technique was better than that of using complete tooth, besides, the effect of nichrome was better than that of rhotanium. CONCLUSION： In the vertical loading condition, the von-mises stress of the alloy post inlay restoration for residual crown of lower jaw first molar decreases, but von-mises stress concentrates relatively on the distal neck of the tooth, specially the buccal side of inside of root of tooth. Besides, the effect of nichrome is better than that of rhotanium. It is indicated that the tooth defection with relatively bad retention form should treat with the pattern of the whole crown restoration or post inlay restoration.
出处
《中国临床康复》
CAS
CSCD
北大核心
2005年第30期112-114,共3页
Chinese Journal of Clinical Rehabilitation
基金
广东省卫生厅科研基金资助项目(A2002153)~~
