牙齿充填材料吸湿率损伤数值模拟

Numerical Simulation of Dental Composite Damage Caused by Water Sorption

摘要:

通过建立三维有限元单胞模型, 考虑界面脱胶损伤效应, 对羟基磷灰石颗粒增强Bis-GMA/TEGDMA聚合物在吸湿作用下的损伤场进行了研究。文中建立了3种不同的单胞模型, 分别用来研究不同的颗粒含量、粘结强度和吸湿率对界面脱胶损伤的影响, 重点放在应力分布形式和应力传递方式。采用有损和无损伤模型预测了牙齿充填材料的杨氏模量和断裂强度, 结果显示考虑脱胶损伤时, 模拟结果与现有的实验数据相吻合。同时就应力传递屏蔽作用进行了对比研究, 并将FCC单胞模型推广, 用于预测承受三点弯曲测试的临界载荷。

关键词:吸湿率, 牙齿充填材料, 界面脱胶损伤, 有限元方法(FEM), 单胞模型

Abstract:

Damage effects of water sorption on mechanical properties of the hydroxyapatite particle reinforced Bis-GMA/TEGDMA copolymer (HA/Bis-GMA/TEGDMA) have been predicted using 3-D finite cell models. Three different cell models were used to determine the influence of varying particle contents, interphase strength and moisture concentration on the debonding damage. The stress distribution pattern has been examined and the stress transfer mode has been clarified. The Young’s modulus and fracture strength of the Bis-GMA/TEGDMA composite were also predicted using the model with and without consideration of the damage. The former results with consideration of the debonding damage are in good agreement with existing literature experimental data. The shielding effect of our proposed model and an alternative approach were discussed. The FCC cell model has also been extended to predict the critical load for the damaged and the undamaged composite subject to the 3-point flexural test.

Key words:water sorption, dental composite, interphase debonding, finite element method (FEM), unit cell model