不同的修复设计和材料对破裂牙应力分布的影响:有限元分析研究
Ting Liu1, Yinghao Huang1, Yue Li1
1Nanjing Stomatological Hospital, Affiliated Hospital of Medical School, Institute of Stomatology, Nanjing University, Nanjing, China.
BMC oral health
|January 8, 2025
概括
IPS e.max CAD (EMX) 修复,包括在线层,覆盖层和未填充的闭合 Veneers,有效地降低了裂纹牙的应力度,防止了进一步的裂纹传播. 岩终极 (LU) 修复显示了更高的压力.
科学领域:
- 生物材料科学 生物材料科学
- 牙科材料 牙科材料
- 计算力学 计算力学 计算力学
背景情况:
- 破裂的下第一个牙构成了重大的临床挑战.
- 修复性材料的选择会影响应力分布和裂传播.
- 有限元分析 (FEA) 是模拟生物机械行为的宝贵工具.
研究的目的:
- 为了比较压力分布和裂传播在破裂的下牙.
- 为了评估onlay,覆盖和封闭面板修复.
- 评估两个CAD/CAM材料:Lava Ultimate (LU) 和IPS e.max CAD (EMX) 的使用情况.
主要方法:
- 创建了一个破裂下第一个的3D FEA模型.
- 设计了四个修复模型:onlay,overlay和两个封闭面板.
- 在用LU和EMX材料制造的模型上模拟了三种闭合力负荷.
主要成果:
- 所有的修复都将应力度从裂的下边缘转移到顶部.
- 经EMX恢复的上层,覆盖层和封闭层2在破裂区域表现出较低的应力,特别是在侧向力 (225N) 下.
- 封闭层1 (含树脂填充) 的应力分布较差,应力度高于封闭层2 (未填充).
结论:
- 与LU相比,EMX修复 (onlay,overlay,闭层2) 显示出优异的应力减轻.
- 带有内部树脂填充剂的封闭面板在裂的下边缘增加了应力.
- 涂层,覆盖和未填充的封闭面板修复可能会防止进一步的裂传播.
相关概念视频
Stress Concentrations
272
Stress concentration is when stress intensifies near discontinuities such as holes or abrupt cross-sectional changes in a structural member. This localized stress can often surpass the average stress within the member. The stress distribution in flat bars, either with a circular hole or varying widths connected by fillets, can be determined experimentally using a photoelastic method. The results are based on ratios of geometric parameters like the ratio of the hole's radius to the smaller...
272
Transformation of Plane Stress
198
Studying stress transformation is essential in understanding how stress components within a material, like a cube under plane stress, change with rotation. This change is analyzed by considering a prismatic element within the cube. As the element rotates, the stress components acting on it—both normal and shearing stresses—change in magnitude and orientation. This change is quantified using trigonometric functions of the rotation angle, relating the forces acting on the rotated element's...
198
Stress: General Loading Conditions
300
To grasp the intricacy of real-world conditions where multiple loads are applied simultaneously to a structure, one might visualize a section passing through a specific point within a body, aligned parallel to the xy plane. This section is subjected to various forces, including original loads, normal forces, and shearing forces.
The shearing force, possessing potential directionality within the plane of the section, is simplified into two component forces running parallel to the x and y axes....
The shearing force, possessing potential directionality within the plane of the section, is simplified into two component forces running parallel to the x and y axes....
300
Flexural Stress
232
When analyzing bending in symmetric members, it's crucial to understand how stresses distribute when subjected to bending moments. This stress distribution is effectively described by applying fundamental mechanics and material science principles, particularly Hooke's Law for elastic materials.
Hooke's Law states that within the material's elastic limits, stress is directly proportional to strain. In a member experiencing a bending moment, the strain at any point is relative to...
Hooke's Law states that within the material's elastic limits, stress is directly proportional to strain. In a member experiencing a bending moment, the strain at any point is relative to...
232
Components of Stress
201
Stress analysis under multiple loading conditions is intricate, necessitating a comprehensive grasp of normal and shearing stresses. Consider a small cube at point O, subjected to stress on all six faces, visible or not. Normal stress components σx, σy, σz act perpendicularly to the x, y, and z axes. Shearing stress components τxy and τxz are exerted on faces perpendicular to these axes.
Interestingly, the hidden cube faces also experience these stresses, equal and...
Interestingly, the hidden cube faces also experience these stresses, equal and...
201
Fatigue
172
Fatigue occurs when materials rupture under repeated or fluctuating loads, even at stress levels far below their static breaking strength. It typically results in brittle failure, even for ductile materials. It is a critical consideration in designing machines and structural components subjected to repetitive or varying loads. The nature of these loadings can range from fluctuating loads like unbalanced pump impellers causing vibrations to repeatedly bending a thin steel rod wire back and forth...
172


