上海口腔医学 ›› 2022, Vol. 31 ›› Issue (6): 621-624.doi: 10.19439/j.sjos.2022.06.010

• 论著 • 上一篇    下一篇

不同材料及不同固位深度的髓腔固位冠修复下颌第二磨牙的三维有限元分析

高琳, 韩祥永, 徐晓明   

  1. 上海市闵行区牙病防治所 口腔修复科,上海 201107
  • 收稿日期:2022-07-19 修回日期:2022-08-28 发布日期:2022-12-29
  • 通讯作者: 徐晓明,E-mail:xxm603@126.com
  • 作者简介:高琳(1988-),女,硕士研究生,主治医师,E-mail:lingao711@163.com

Three-dimensional finite element analysis of three-material endocrown in the restoration of dental defects of mandibular second molars

GAO Lin, HAN Xiang-yong, XU Xiao-ming   

  1. Prosthodontics Clinic, Shanghai Minhang District Dental Cennter. Shanghai 201107, China
  • Received:2022-07-19 Revised:2022-08-28 Published:2022-12-29

摘要: 目的: 构建根管治疗后下颌第二磨牙髓腔固位冠修复的三维有限元模型,分析面不同预备厚度对修复体和牙体组织应力分布的影响。方法: 利用锥形束CT(CBCT)扫描逆向建立下颌第二磨牙的三维有限元模型,构建髓腔固位冠进行修复。根据冠部材料和面厚度不同,构建面分别为1、2、3 mm厚度,材料分别为玻璃陶瓷、二硅酸锂和氧化锆的修复体,采用垂直向和斜向载荷(30°)分别加载 200 N 的力,观察应力分布情况,比较应力集中部位及应力峰值的差异。结果: 修复体和牙体组织应力强度峰值随面厚度增加先增大后减小,垫底材料应力强度峰值随面厚度增加而减小,牙体组织和垫底材料的应力强度峰值随修复体材料杨氏模量增大而增大。斜向加载时,应力强度峰值比垂直加载时增大。结论: 修复体面厚度预备2 mm,有利于缓解髓腔固位冠修复后牙体组织的应力集中。修复体材料杨氏模量越高,髓腔固位冠牙体组织应力越集中。

关键词: 髓腔固位冠, 面厚度, 玻璃陶瓷, 二硅酸锂, 氧化锆

Abstract: PURPOSE: To analyse the effect of restoration and tooth tissue stress distribution under different occlusal preparation thickness, based on three-dimensional finite element modal of the mandibular second molar with root canal therapy and endocrown restorations. METHODS: A mandibular second molar was scanned by cone-beam CT (CBCT) and a three-dimensional finite element model with endocrown restortions was established. Three kinds of endocrown restorations materials with different elastic modulus (glass ceramic, lithium disilicate ceramic and zirconia), and three types of occluscal thickness (1, 2 and 3 mm) were adopted. With a 200 N force loaded vertically and obliquely, the distribution and magnitude of stress in the tooth tissue and endocrown restorations were investigated by three-dimensional finite element analysis. RESULTS: The restoration and tooth tissue maximum stress values were increased firstly and then decreased with the increasing of occlusal thickness; the base material maximum stress values were decreased with the increasing of occlusal thickness; the maximum stress values of tooth tissue and base material were increased with the increasing of restoration material's Young's modulus. Compared to the loading in vertical direction, the maximum stress values were increased with loading in oblique direction. CONCLUSIONS: It's beneficial for tooth tissue to reduce the stress concentration under 2mm thickness. The stress on endocrown will be more concentrated with the increasing of restoration material’s Young's modulus.

Key words: Endocrown, Occlusal thickness, Glass ceramic, Lithium disilicate ceramic, Zirconia

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