[不同方法修复深楔状缺损前磨牙的三维有限元分析]
[Three-dimensional finite element analyses of the deep wedge-shaped defective premolars restored with different methods].
作者信息
Ling Zhao, Liyuan Yang, Cuiling Liu, Xu Gao
机构信息
Dept. of Prosthodontics, School of Stomatology, Shandong University, Shandong Provincial Key Laboratory of Oral Tissue Regeneration, Jinan 250012, China.
Dept. of Stomatology, Qilu Hospital, Shandong University, Jinan 250012, China.
出版信息
Hua Xi Kou Qiang Yi Xue Za Zhi. 2017 Feb 1;35(1):77-81. doi: 10.7518/hxkq.2017.01.012.
OBJECTIVE
The objective of this paper is to analyze the stress distribution in the deep wedge-shaped defective mandibular first premolars restored with different methods.
METHODS
Three-dimensional finite element models of mandibular first premolar with deep wedge-shaped defect were created. The model, which was untreated after root canal treatment, served as the control group. Then, according to different treatment designs, four experimental groups were established as follows: resin filling (A), post restoration after resin filling (B), crown restoration after resin filling (C), and post and crown restoration after resin filling (D). Four different post materials were then chosen for establishing the subgroup models: fiber post (B1, D1), AuPd post (B2, D2), pure Ti post (B3, D3), and CoCr post (B4, D4). A force of 100 N was applied at a 30° angle on the buccal-inclined surface near the top of the buccal cusp. The maximum principal stress and Von Mises stress were investigated using finite element analysis software.
RESULTS
- For the control group, the maximum principal stress and Von Mises stress of the residual dentine were the same as those of the tip of the defect. 2) Compared with the control group, the maximum principal stress and Von Mises stress of groups A, B, C, and D decreased greatly (P<0.05). The maximum principal stress and Von Mises stress of groups C and D with crowns were similar. The maximum principal stress and Von Mises stress of the post-dentine surface of groups B and D with fiber post were less than those in the cast metal post models (P<0.05). 3) The displacement of the buccal cusp of group A was similar to that of the control group (P>0.05) and larger than those in groups B, C, and D (P<0.05).
CONCLUSIONS: It is necessary for deep wedge-shaped defective teeth to be treated with full crowns, but a post is not necessary. If a post is used, fiber post with elastic modulus closer to the dentine is more suitable than metal post. .
目的
本文旨在分析采用不同方法修复的下颌第一前磨牙深楔状缺损中的应力分布情况。
方法
创建下颌第一前磨牙深楔状缺损的三维有限元模型。根管治疗后未作处理的模型作为对照组。然后，根据不同的治疗设计，设立如下四个实验组：树脂充填（A组）、树脂充填后桩修复（B组）、树脂充填后全冠修复（C组）以及树脂充填后桩核冠修复（D组）。接着选择四种不同的桩材料建立亚组模型：纤维桩（B1、D1）、金钯合金桩（B2、D2）、纯钛桩（B3、D3）和钴铬合金桩（B4、D4）。在靠近颊尖顶部的颊侧倾斜面上以30°角施加100 N的力。使用有限元分析软件研究最大主应力和冯·米塞斯应力。
结果
1）对照组中，剩余牙本质的最大主应力和冯·米塞斯应力与缺损尖端的应力相同。2）与对照组相比，A、B、C、D组的最大主应力和冯·米塞斯应力均显著降低（P<0.05）。C组和D组采用全冠修复后的最大主应力和冯·米塞斯应力相似。B组和D组采用纤维桩的桩周牙本质表面的最大主应力和冯·米塞斯应力小于铸造金属桩模型（P<0.05）。3）A组颊尖的位移与对照组相似（P>0.05），且大于B、C、D组（P<0.05）。
结论
下颌第一前磨牙深楔状缺损牙采用全冠修复是必要的，但桩并非必需。若使用桩，弹性模量更接近牙本质的纤维桩比金属桩更合适。
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