侧向力对楔状缺损充填材料应力分布的影响

The influence of lateral occlusal forces to the stress distribution of restorative material of wedge-shaped defect

目的研究楔状缺损充填治疗后,侧向力作用对充填材料的应力分布影响。方法建立含楔状缺损的上颌第一前磨牙三维有限元模型,在模型的缺损部分用模拟玻璃离子材料进行充填;对模型施加不同方向的载荷,对充填体部分进行应力分析。结果当力方向与牙体长轴平行时,充填体受到的应力较小。当力方向与受力牙尖斜面垂直时,充填体受到的应力明显增大,随着力方向偏移角度增加,此区域应力集中情况更加明显。结论临床上楔状缺损充填治疗之后,应当对牙体进行适当的调磨,降低牙尖斜度以降低牙体受到的侧向力,以降低充填材料的应力负荷。

Objective To evaluation the influences of lateral occlusal forces to stress distribution in filling material after the restorative therapy of wedge-shaped defect.Methods A three-dimensional finite element model of maxillary first premolar with wedge-shaped defect was established.The defect zone of the model with simulated glass ionomer was restored.Loads of different directions were applied on the model and stress analysis of restorative material were conducted.Results When the loading direction was parallel to the tooth long axis,restorative material unit subjected to relative small stress.When the loading direction was vertical to the cusp inclined plane,stress endured by restorative material unit was significantly increased,as the angle of loading inclination increased,the increase of stress became more pronounced.Conclusion After the restorative treatment of wedge-shaped defects in clinical,occlusal adjustment should be applied to reduce the inclination of cusp to relieve the lateral forces subjected by tooth so as to ease the stress burden of restorative material.