楔状缺损深度与角度对下颌第一前磨牙牙体应力分布影响的有限元分析

【摘要】 目的 采用三维有限元法建立下颌第一前磨牙多类型楔状缺损的有限元模型,通过力学模拟比较不同缺损角度与不同的缺损深度,对下颌第一前磨牙牙体组织应力分布的影响。为临床楔状缺损的临床治疗提供生物力学依据。方法 建立下颌第一前磨牙颊侧牙颈部多类型楔状缺损的有限元模型,其中缺损深度分别为1mm、2mm,缺损角度分别为30°、45°、60°。在软件中通过对牙体及牙周组织等材料进行参数设定,通过力的加载,对结果进行分析。结果 在力的载荷下,无论楔状缺损的深度与角度如何,剩余牙体组织的最大主应力与Von Mises应力峰值集中区域均出现在楔状缺损的尖端;当缺损深度一定时,随着楔状缺损角度变大,牙体组织的Von Mises应力峰值与最大主应力峰值反而下降;当楔状缺损的角度一定时,缺损深度变大,则余留牙体组织的Von Mises应力与最大主应力峰值也越大。结论 楔状缺损未经修复时,楔状缺损的尖端发生牙体折裂的风险较大;其余条件一定时,楔状缺损深度越大,则缺损尖端承受的拉应力越大,越容易破损;其余条件一定时,牙体应力会随着楔状缺损角度的增加而下降。更多还原

【Abstract】 Objective To establish finite element model of multiple types of wedge-shaped defects in the mandibular first premolar using a threedimensional finite element method.The effects of different angles and depths of defect on the stress distribution of the first premolar of the mandible are compared through mechanical simulation.To provide a biomechanical basis for the clinical treatment of clinical wedge-shaped defect.Methods Finite element model of multiple types of wedge-shaped defects in the buccal side of the mandibular first premolar were established.The depth of the defects were1 mm and 2 mm,and the angles of the defects were 30°,45° and 60°.In the software,parameters were set for the tooth tissue and periodontal tissue,and the results were analyzed by force loading.Results Under the load of force,regardless of the depth and angle of the wedge-shaped defect,the area of maximum principal stress and peak Von Mises stress of the remaining tooth tissue appeared at the tip of the wedge-shaped defect.As the angle increased,the peak Von Mises stress and the maximum principal stress peak of the dental tissue decrease.When the angle of the wedge-shaped defect were constant,the depth of the defect became larger,and the peak Von Mises stress and the maximum principal stress of the remaining dental tissue also increased.Conclusion When the wedge-shaped defect is not repaired,the tip of the wedge-shaped defect has a greater risk of tooth fracture.When other conditions are unchanged,the greater the depth of the wedge-shaped defect,the larger the tensile strength of the defect tip,the easier it is to break.When the other conditions are unchanged,the tooth stress will decrease as the angle of the wedge-shaped defect increases.更多还原