Biomedical subjects

F Takashima

Publications and source records attributed to F Takashima.

At least 37 records · Page 2Linked to original sources

PubMed1990

[Stress analysis of titanium-hydroxyapatite implant. Effect of titanium diameter on reinforcement and calculation of implant diameter].

In order to evaluate the effect of titanium diameter on reinforcement of titanium-hydroxyapatite implant and calculate the diameter of the implant under loading, stress analysis was performed using the finite element method. In finite element model, 100% or 70% of root length was supported by PMMA in place of bone and the implant was loaded 15 kgf at 45 degrees of the implant axis. The results were obtained as follows, 1. In the case of 100% support, the titanium diameter had little effect on the reinforcement of the implant, whereas in the case of 70% support, it had much effect. 2. The diameter of this implant was calculated to be more than 3.7 mm under loading. From these results and the view point of manufacturing techniques, the diameter of this implant was supposed to need 4.0 mm and that of titanium was to be 2.0 mm.

Dental Implants↗

PubMed1990

The influence of materials difference on stress distribution and bone remodeling around alumina and titanium dental implants.

The long-term complications of dental implants are associated with loosening of the implant-bone interface, due to bone resorption and subsequent connective tissue interposing at the implant-bone interface. Mechanical stresses, which are induced in the surrounding bone, play a key role in the interface bone remodeling. In the present study, it is investigated how local stress patterns are associated with local bone structure. For identical geometry alumina, and titanium implants, the stress patterns, determined in the finite element models with boundary conditions, are compared with the local bone structure found in animal experiments. The results indicate that there appears to be relationship between the stress patterns and the bone remodeling at the implant-bone interface independently on the materials properties in alumina and titanium.

Aluminum Oxide↗

PubMed1989

[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.

Dental Implants↗

PubMed1988