中国组织工程研究

中国组织工程研究 ›› 2017, Vol. 21 ›› Issue (30): 4823-4829.doi: 10.3969/j.issn.2095-4344.2017.30.012

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

有限元分析上颌中切牙唇、舌向斜形缺损后纤维桩核冠修复三维模型的应力分布

蔡  跃，黄  英，张  慧，郭  玲
  

  1. 西南医科大学附属口腔医院，四川省泸州市 646000
  • 收稿日期:2017-08-21 出版日期:2017-10-28 发布日期:2017-11-07
  • 通讯作者: 郭玲，副教授，西南医科大学附属口腔医院修复科，四川省泸州市 646000
  • 作者简介:蔡跃，男，1991年生，四川省宜宾市人，汉族，西南医科大学在读硕士，主要从事口腔修复学研究。
  • 基金资助:
    四川省科技计划项目(2017JY0111)：钛表面N-乙酰半胱氨酸自组装膜的构建、功效及机制研究

Stress distribution of the three-dimensional post-crown model with labial and lingual oblique defects of the maxillary central incisor: a finite element analysis

Cai Yue, Huang Ying, Zhang Hui, Guo Ling
  

  1. Affiliated Stomatological Hospital of Southwest Medical University, Luzhou 646000, Sichuan Province, China
  • Received:2017-08-21 Online:2017-10-28 Published:2017-11-07
  • Contact: Guo Ling, Associate professor, Affiliated Stomatological Hospital of Southwest Medical University, Luzhou 646000, Sichuan Province, China
  • About author:Cai Yue, Studying for master’s degree, Affiliated Stomatological Hospital of Southwest Medical University, Luzhou 646000, Sichuan Province, China
  • Supported by:
    the Science and Technology Plan of Sichuan Province, No. 2017JY0111

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254

被引次数

3

摘要：

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文题释义：
牙本质肩领：是桩核冠修复体的冠边缘至核边缘之间的一牙本质壁，牙本质肩领能增强根部牙体组织的抗力，增加其高度能使根部牙体所受到的应力更均匀，反之无牙本质肩领则会造成应力集中，增大牙体组织及纤维桩折断的可能。
应力：物体由于外因(受力、湿度、温度场变化等)而变形时，在物体内各部分之间产生相互作用的内力，以抵抗这种外因的作用，并试图使物体从变形后的位置恢复到变形前的位置。在所考察的截面某一点单位面积上的内力称为应力。同截面垂直的称为正应力或法向应力，同截面相切的称为剪应力或切应力。
 
背景：临床上牙本质肩领对桩核冠修复体的抗力和固位及边缘密封性有着重大作用。
目的：采用有限元分析唇、舌向斜形缺损上颌中切牙纤维桩-树脂核-全瓷冠三维模型的应力分布。
方法：挑选1颗标准离体人上颌中切牙，使用锥形束CT扫描后，导入Mimics17软件，利用CAD、UG软件构建出唇侧、舌侧肩领有缺损的桩核冠模型，分别假设唇侧或舌侧断端低，肩领有缺损，限定缺损侧肩领为0 mm，按照唇侧肩领高度-舌侧肩领高度进行分组(0 mm-0 mm、0 mm-0.5 mm、0 mm-1.0 mm、0 mm-1.5 mm、0 mm-2.0 mm、0.5 mm-0 mm、1.0 mm-0 mm、1.5 mm-0 mm、2.0 mm-0 mm、0.5 mm-0.5 mm、1.0 mm-1.0 mm、1.5 mm-1.5 mm、2.0 mm-2.0 mm)，在全瓷冠切1/3、中1/3交界处，施加与牙长轴成45°的100 N静载荷力，采用有限元分析根尖部牙本质及纤维桩的Von Mises应力分布。
结果与结论：①根尖部牙本质应力分布：在唇、舌侧肩领均完整的情况下，随着肩领高度的增加，牙根部Von Mises应力从集中于颈部的趋势逐渐变得更分散均匀，峰值应力随肩领高度增加而逐渐减小。在牙本质肩领有缺损的条件下，无论是舌侧或唇侧有肩领的情况下，牙根部Von Mises应力峰值较无牙本质肩领的情况有所减小，但同等高度下，舌侧有牙本质肩领组应力峰值减小更为明显，接近牙本质肩领完整组；②纤维桩应力分布：在唇、舌侧肩领均完整的情况下，随着肩领高度的增加，纤维桩Von Mises应力峰值逐渐减小。在牙本质肩领有缺损的条件下，无论是舌侧或唇侧有肩领的情况下，纤维桩Von Mises应力峰值较无牙本质肩领的情况均有所减小，但唇侧有牙本质肩领组应力峰值减小比舌侧肩领组更为明显；③结果表明：舌侧肩领对减小根部牙体应力集中较唇侧肩领明显，舌侧肩领高度有利于增强牙体抗力；唇侧肩领对减小纤维桩和粘接剂层的峰值应力较舌侧肩领明显，唇侧肩领高度有利于增加纤维桩冠的固位和稳定，且至少保留0.5-    1.0 mm唇侧肩领效果更明显。

关键词: 生物材料, 口腔生物材料, 纤维桩, 全瓷冠, 上颌中切牙, 牙本质肩领, 牙体缺损, Von Mises应力, 三维有限元

Abstract:

BACKGROUND: Clinically, dentin ferrule has great influence on resistance, retention and edge sealing of post-core crowns.
OBJECTIVE: To analyze the stress distribution of a three-dimensional post-crown model with labial and lingual oblique defects of the maxillary central incisor by finite element analysis.
METHODS: A standard maxillary central incisor was selected and scanned by cone beam CT, and then, scanning data were imported to Mimics17 software. The CAD and UG software were used to construct the post-crown model with labial and lingual oblique defects. The dentin ferrule height of the defective side was designed to be 0 mm, and according to the dentin ferrule height at labial side-the dentin ferrule height at lingual side, there were the following groups: 0 mm-   0 mm, 0 mm-0.5 mm, 0 mm-1.0 mm, 0 mm-1.5 mm, 0 mm-2.0 mm, 0.5 mm-0 mm, 1.0 mm-0 mm, 1.5 mm-0 mm,   2.0 mm-0 mm, 0.5 mm-0.5mm, 1.0 mm-1.0 mm, 1.5 mm-1.5 mm, 2.0 mm-2.0 mm). In the crown cut 1/3, 1/3 at the junction, the Von Mises stress distribution of the root dentin and fiber post was analyzed by finite element analysis using a force of 100 N at 45° to the long axis of the tooth
RESULTS AND CONCLUSION: (1) Root dentin stress distribution: In the case that the dentin ferrule at both labial and lingual sides was complete, with the increasing of the dentin height, the root Von Mises stress from the focus on the neck gradually became more evenly distributed and the peak stress gradually decreased. In the case of defective dentin ferrule, the peak of the Von Mises stress which had the dentin ferrule at the lingual side or the labial side was lower than that without the dentin ferrule, but at the same height, the dentin ferrule’s stress reduction at the lingual side was more obvious, close to the dentin ferrule ferrule complete group. (2) Fiber post stress distribution: in the case that the dentin ferrule at both labial and lingual sides was complete, with the increasing of the dentin height, fiber post’s Von Mises stress was gradually reduced. In the case of defective dentin ferrule, fiber post’s Von Mises stress which had dentin ferrule at the labial or lingual side was lower than that without the dentin ferrule, but at the same height, the dentin ferrule’s stress reduction at the labial side was more obvious. Overall, the lingual ferrule is more obvious on reducing root stress concentration than the labial ferrule, and the lingual ferrule height is beneficial to enhancing tooth resistance; the labial ferrule is more obvious on reducing the peak stress of fiber post and luting cement than the lingual ferrule, and the labial ferrule height is beneficial to increasing the retention and stabilization of the fiber post-core crown, and the effect becomes more obvious with at least 0.5-1.0 mm labial ferrule.

Key words: Post and Core Technique, Crowns, Incisor, Dentin, Dental Stress Analysis, Finite Element Analysis, Tissue Engineering

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