Chen Ruizhen, Chen Yao, Zheng Zhiqiang, Lin Jie
Fujian Key Laboratory of Oral Diseases, School and Hospital of Stomatology, Fujian Medical University, 246 Yangqiao Zhong Road, Fuzhou, Fujian, 350002, PR China.
Department of Crown and Bridge, School of Life Dentistry at Tokyo, The Nippon Dental University, 1-9-20 Fujimi, Chiyoda-ku, Tokyo, 102-8159, Japan.
BMC Oral Health. 2024 Dec 20;24(1):1522. doi: 10.1186/s12903-024-05334-y.
The retention force of a realistic clasp is influenced by multiple, interrelated factors, which complicates the identification of the fundamental relationship between clasp geometry and retention force. While realistic clasps exhibit various shapes, they share basic geometric elements such as length, diameter, and curvature. Simpler geometries are often more conducive to identifying the underlying issues. The aim is to investigate the relationship between clasp geometry and retention force using finite element analysis.
A three-dimensional clasp model was created in ANSYS 19.0 (ANSYS, USA). Two types of models were analyzed: rod-shaped clasps with varying lengths (1-15 mm) and diameters (0.6-1.6 mm), and bending clasps with different base widths (6-12 mm) and heights (0.5-5 mm), all made from cobalt-chromium alloys. For the rod models, stress and retention force were assessed by applying displacement loads and analyzing data with nonlinear regression. For the bending models, a similar analysis was conducted for varying base widths and heights.
Maximum stress consistently concentrated at the clasp base. In rod models, retention force decreased with the third power of length and increased with the fourth power of diameter. For bent specimens, the retention force was approximately inversely proportional to the cube of the base width and inversely proportional to the first power of the height.
Finite element analysis revealed distinct functional relationships between clasp geometry and retention force. Further laboratory validation is required.
逼真的卡环固位力受多种相互关联的因素影响，这使得确定卡环几何形状与固位力之间的基本关系变得复杂。虽然逼真的卡环呈现出各种形状，但它们具有诸如长度、直径和曲率等基本几何元素。更简单的几何形状通常更有利于识别潜在问题。目的是使用有限元分析研究卡环几何形状与固位力之间的关系。
在ANSYS 19.0（美国ANSYS公司）中创建三维卡环模型。分析了两种类型的模型：长度（1 - 15毫米）和直径（0.6 - 1.6毫米）不同的杆状卡环，以及基部宽度（6 - 12毫米）和高度（0.5 - 5毫米）不同的弯曲卡环，均由钴铬合金制成。对于杆状模型，通过施加位移载荷并使用非线性回归分析数据来评估应力和固位力。对于弯曲模型，对不同的基部宽度和高度进行了类似的分析。
最大应力始终集中在卡环基部。在杆状模型中，固位力随长度的三次方减小，随直径的四次方增加。对于弯曲试件，固位力大约与基部宽度的立方成反比，与高度的一次方成反比。
有限元分析揭示了卡环几何形状与固位力之间明显的函数关系。需要进一步的实验室验证。
