不同材料及厚度对嵌体抗折裂强度的影响及三维有限元分析  

Effect of materials and thicknesses on fracture resistance of inlay and three-dimensional finite element analysis

作　　者：李施园 孙志达[1] 梁佳瑜 刘梅[1] LI Shiyuan;SUN Zhida;LIANG Jiayu;LIU Mei(Jiangsu Key Laboratory of Oral Diseases,Nanjing Medical University,Department of Conservative and Endodontic Dentistry,Affiliated Hospital of Stomatology,Nanjing Medical University,Nanjing 210029,China)

机构地区：[1]南京医科大学口腔疾病研究江苏省重点实验室南京医科大学附属口腔医院牙体牙髓科

出　　处：《口腔医学》2019年第12期1073-1077,共5页Stomatology

基　　金：江苏省卫生计生委科研课题—青年基金(Q201604);江苏高校优势学科建设工程资助项目(2018-87)

摘　　要：目的研究不同材料及牙合面厚度对嵌体抗折裂强度及应力分布的影响,为临床利用提供实验基础及支持。方法选用右下第一磨牙标准近中邻牙合面洞嵌体预备体,扫描得到数字化模型,软件调整嵌体厚度,3D打印金属代型;嵌体材料选用IPS e.max和Vita enamic。粘结后对嵌体进行抗折裂强度试验。选取成人健康右下第一磨牙CBCT数据,进行数字化模型模拟,分析不同材料及牙合面厚度时剩余牙体硬组织的应力分布。结果不同厚度的IPS e.max嵌体抗折裂强度存在差异(P<0.05),2.0 mm时最大;Vita enamic组也存在差异(P<0.05),2.5 mm时最大。嵌体厚度同为2.0 mm时,IPS e.max的抗折裂强度优于Vita enamic(P<0.05)。应力分布分析中,相同厚度下,嵌体等效应力IPS e.max组均大于Vita enamic组。剩余牙釉质的等效应力,IPS e.max组低于健康牙齿;Vita enamic组厚度为2.0、2.5 mm时则有所增加。嵌体修复后剩余牙本质的等效应力峰值均大于完整牙齿,但随着厚度的增加,峰值在减小。结论 IPS e.max嵌体厚度为2.0 mm时,抗折裂强度最大。IPS e.max嵌体的抗折裂强度比Vita enamic更大,并且承担了更多的应力,更有利于剩余牙体硬组织的保存。Objective To study the influence of different thicknesses and materials on the fracture resistance of inlays and the change of stress distribution, to provide experimental basis and support for restoration with inlays in clinic. Methods The standard preparation of inlay of the right lower first molar was selected, and the model was obtained by scanning. The thickness of the inlay was adjusted by software, and the metal dies were made by 3 D printing. IPS e.max and Vita enamic were selected as inlay materials. Fracture resistance was tested on the inlays after bonding. CBCT data of lower right first molars of a healthy adult were selected to carry out the digital model simulation. The stress distribution of inlay and remaining teeth with different thicknesses and materials were observed and analyzed. Results There were differences in fracture resistance among IPS e.max groups(P<0.05), and the largest fracture resistance was at 2.0 mm. There were differences among Vita enamic groups(P<0.05), and the largest fracture resistance was at 2.5 mm. IPS e.max had higher fracture resistance(P<0.05) when the inlay thickness was 2.0 mm. In three-dimensional finite element analysis, the equivalent stress of IPS e.max inlays was larger than Vita enamic under the same thickness. The equivalent stress of residual enamel in IPS e.max group was lower than that of healthy teeth, while in Vita enamic group, the equivalent stress of residual enamel increased when the thickness was 2.0 mm and 2.5 mm. The peak equivalent stress of dentin restored with both materials was larger than that of intact dentin, but the peak equivalent stress of residual dentin decreased with the increase of thickness. Conclusion IPS e.max inlay with 2.0 mm has the largest fracture resistance. The fracture strength of IPS e.max is larger than that of Vita enamic and bears more stress than Vita enamic, which is more conducive to the preservation of the remaining tooth hard tissue.

关 键 词：嵌体 抗折裂强度 厚度 材料 三维有限元分析 

分 类 号：R783.1[医药卫生—口腔医学]