[Dynamic study of titanium-hydroxyapatite implant by finite element method]

In order to evaluate the strength of titanium-hydroxyapatite implant, adhesive tests and loading tests were performed. The results of the loading tests were compared with the computed results by finite element method. Axisymmetric 8-node quadrilateral element for arbitrary loading was used for the analysis. Implants of 3.2 mm diameter were loaded at 45 degrees of the implant axis by using an Instron testing machine at crosshead speed of 0.5 mm/min. The results were obtained as follows: 1. The mean value of the adhesive test of titanium-resin (Panavia)-hydroxyapatite was 2.3 kgf/mm2. The fracture was caused at Panavia layer. 2. The mean value of the fracture loads of implants was 10.9 kgf. The fracture was caused at Panavia layer, similarly to the result described in 1. 3. The principal stress caused at Panavia layer of the implant was approximately 2.3 kgf/mm2, which was calculated under the load of 10.9 kgf by the finite element method. This result corresponds to that of the loading test described in 1 and 2. It was ascertained by these findings that finite element method is effective for the evaluation of the strength of this implant.