Session 3 Chair: Eri Makihara (kyushu Dental University)



Mechanical Strength Analysis of Extracoronal Magnetic Attachment by Three-

Dimensional Finite Element Method

-Report II Introduction of elasto-plastic analysis-


A. Otoda, Yo. Ohno, K. Shiraishi, T. Masuda, K. Okamoto, T. Itakura, Y. Nakamura,

Y. Takada1, Yu. Ohno, Y. Tanaka.


Department of Removable Proshodontics, School of Dentistry Aichi-Gakuin University

1Division of Dental Biomaterials, Tohoku University Graduate School of Dentistry




 Ohno from our department reported on the mechanical strength analysis of an extracoronal magnetic attachment using Au-Ag-Pd alloy by three- dimensional finite element method in the 21st International Conference on Magnetic Applications in Dentistry. However, platinum gold alloy is more frequently used than Au-Ag-Pd alloy in the clinical practice.

 In the present study, we focused on heat treatment of platinum gold alloy, and mechanical strength analysis of an extracoronal magnetic attachment was performed.

 As a preliminary experiment, the stress-strain curve of dental gold casting alloy (PGA-3, ISHIFUKU Metal Industry Co., Ltd) after heat treatment was calculated, followed by the elasto-plastic analysis of a simple-shaped sample based on the stress-strain curve. The finite element model of an extracoronal magnetic attachment was fabricated to perform elasto-plastic analysis. The material constant was determined from a known value and stress-strain curve of platinum gold alloy.

 The preliminary experiment confirmed the validity of the elasto-plastic analysis by three-dimensional finite element method. Three-dimensional finite element analysis of the main experiment showed that the elastic limit of an extracoronal magnetic attachment of platinum gold alloy existed around 800 N.