Validation of Finite Element Analysis in
Dental Ceramics Research
Lisa A. Lang, DDS, MS
Rui-Feng Wang BS,
Byungsik Kang, PhD
Shane N. White, DDS, MS
Abstract: The purpose of this study was to demonstrate the advantages of combining results from mechanical testing with finite element analysis data in determining the strength of a layered ceramic beam when the layered materials and positions are varied. Eight finite element 5.0 x 20.0 x 1.0 mm layered beams were modeled (Fig 1).
Fig. 1. The Layered Beams
The beams consisted of both the Procera® aluminum oxide coping core material and the Procera® AllCeram Porcelain veneering material. Four of the beams were of the exact same layered arrangements as physical samples from a previously published study. The remaining four modeled beams provided intermediate layered arrangements not evaluated in the earlier study. A force in Newtons was applied to each beam in the center of the top layer of the beam. The FEA was performed and the data compared with the mechanical strength results from the earlier study. The FEM data demonstrated a linear decrease in strength as the layered thickness of the core material was decreased and the layering thickness of the veneer material was increased. The decreasing values for the FEM beams were 170 N, 144 N, 140 N, 134 N, 72 N, 43 N, 34 N, and 27 N (Fig. 2).
Fig. 2. Mechanical and Finite Element Analysis Strength Data
The mean load bearing capacity for three of the four mechanically tested beams compared favorably with the FEM data. The strength of the fourth mechanically tested beam, a veneer/core layered arrangement, was 110 N or lower than the same FEM beam modeled (140 N). The 110 N value fell outside the decreasing linear progression for load indicating that the FEM data was more accurate and reliable than the mechanical data.
Conclusions: There is no perfect method for strength testing of dental materials. Both mechanical testing and finite element method have potentials for errors. The best approach for more reliable and valid data is to use the results from both mechanical testing and finite element analyses.
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