中国组织工程研究

中国组织工程研究 ›› 2024, Vol. 28 ›› Issue (10): 1575-1579.doi: 10.12307/2024.258

• 组织工程口腔材料 tissue-engineered oral materials • 上一篇    下一篇

短冠磨牙远中邻牙合缺损髓腔固位冠修复的三维有限元分析

赵苑苑，尚卫华，贺婧艺，李薇鑫，王  桃   

  1. 郑州大学第一附属医院口腔修复科，河南省郑州市  450052
  • 收稿日期:2023-03-01 接受日期:2023-04-12 出版日期:2024-04-08 发布日期:2023-08-19
  • 通讯作者: 王桃，主任医师，硕士生导师，郑州大学第一附属医院口腔修复科，河南郑州市 450052
  • 作者简介:赵苑苑，女，1997年生，河南省洛阳市人，汉族，在读硕士，主要从事口腔修复学方面的研究。

Three-dimensional finite element analysis of distal proximal occlusal defect of short crown molar restored with endocrown

Zhao Yuanyuan, Shang Weihua, He Jingyi, Li Weixin, Wang Tao   

  1. Department of Prosthodontics, First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan Province, China
  • Received:2023-03-01 Accepted:2023-04-12 Online:2024-04-08 Published:2023-08-19
  • Contact: Wang Tao, Chief physician, Master’s supervisor, Department of Prosthodontics, First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan Province, China
  • About author:Zhao Yuanyuan, Master candidate, Department of Prosthodontics, First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, Henan Province, China

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摘要：


文题释义：

短冠磨牙：是指临床牙冠较短的磨牙(牙合龈距< 4 mm)，没有修复空间且牙体缺损的短冠磨牙行根管治疗后常因修复体缺乏固位而易脱落，因此需增加辅助固位形。髓腔固位冠增强固位的同时实现了微创修复，修复时要考虑不同设计的修复体对牙体组织应力的影响。
有限元分析：是将实体模型离散成有限个单元，各个单元之间通过节点连接，通过设置限定的载荷条件对每个单元的力学性质进行分析，最终得到整个模型受力结果的力学分析手段，划分的单元越小数量越多，所得到的数值就越接近准确值。


背景：对于牙冠高度正常的牙齿，不同髓腔固位深度及不同修复材料的髓腔固位冠修复对牙体组织应力大小及抗折性有影响，对于短冠磨牙缺损利用髓腔修复的研究多集中在临床观察及体外抗折性实验。

目的：建立根管治疗后短冠磨牙髓腔固位冠修复的三维有限元模型，分析不同髓腔固位深度及修复材料的修复体对牙本质等效应力分布及大小的影响。
方法：在建立完整短冠下颌第一磨牙模型的基础上，建立不同髓腔固位深度(h=2，3，4 mm)、不同修复材料(氧化锆、二硅酸锂)的髓腔固位冠修复短冠磨牙远中邻牙合缺损的三维有限元模型，采用斜向加载，观察等效应力分布情况，计算牙本质等效应力峰值及近中髓室壁近髓室底等效应力平均值。

结果与结论：①等效应力集中部位：完整短冠磨牙及修复后各模型应力主要集中在近中根近中颈部及近中根舌侧颈部，修复后各模型垫底层对应的近中髓室壁近髓室底处均有应力集中区，其中以髓腔固位深度4 mm组应力集中明显；②在相同修复材料下，修复后各模型牙本质等效应力峰值均以髓腔固位深度3 mm组最小，近中髓室壁近髓室底处牙本质等效应力平均值均为髓腔固位深度3 mm组最小；③在相同固位深度下，氧化锆组及二硅酸锂组牙本质等效应力峰值及近中髓室壁近髓室底处牙本质等效应力平均值均相差不大；④结果表明，在此次实验条件下，短冠磨牙缺损采用髓腔固位冠修复时固位深度为3 mm更有利于保护剩余牙体组织，修复材料选择氧化锆或二硅酸锂对牙本质应力影响区别不大。

https://orcid.org/0009-0000-9340-0297(赵苑苑)

中国组织工程研究杂志出版内容重点：生物材料；骨生物材料；口腔生物材料；纳米材料；缓释材料；材料相容性；组织工程

关键词: 短冠磨牙, 下颌第一磨牙, 髓腔固位冠, 固位深度, 氧化锆, 二硅酸锂, 有限元分析, 等效应力

Abstract: BACKGROUND: For teeth with normal dental crown height, pulp cavity retention crown restoration with different depths of the pulp cavity and different repair materials affects the stress and flexural strength of tooth tissue. For short crown molar defects, the research on pulp cavity repair mainly focuses on clinical observation and in vitro flexural strength experiments. 
OBJECTIVE: To establish a three-dimensional finite element model for short crown molar restored by the endocrown after root canal treatment to analyze the effects of different pulp cavity retention depths and different repair materials on the distribution and size of dentin equivalent stress.
METHODS: Based on establishing the complete model of the short crown mandible first molar, a three-dimensional finite element model was established for repairing the distal adjacent defect of the short crown molar with different pulp cavity retention depths (h=2, 3, 4 mm) and different repair materials (zirconia, lithium disilicate). Under the oblique loading, the equivalent stress distribution was observed. The peak value of dentin equivalent stress and the mean value of equivalent stress near the bottom of the mesial pulp cavity wall were calculated.
RESULTS AND CONCLUSION: (1) Equivalent stress concentration areas: The stress of complete short crown molar and restored models mainly concentrated in the mesial root mesial neck and mesial root lingual neck. The stress concentration area was found in the mesial pulp cavity wall corresponding to the bottom layer of restored models, and the stress concentration was obvious in the 4 mm retention depth group. (2) Under the same repair material, the peak value of dentin equivalent stress was the lowest at 3 mm for all models after repair. The average value of equivalent stress near the bottom of the mesial pulp cavity wall was lowest at 3 mm. (3) Under the same retention depth, there was no significant difference between the two materials in the dentin equivalent stress peak and the mean value near the bottom of the mesial pulp cavity. (4) The results showed that under the conditions of this experiment, the endocrown was used to repair the defect of the short crown molar and the retention depth was 3 mm, which was more beneficial to protect the remaining dental tissue. The selection of zirconia or lithium disilicate as the repair material had little effect on the dentin stress. 

Key words: short crown molar, mandibular first molar, endocrown, retention depth, zirconia, lithium disilicate, finite element analysis, equivalent stress

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