다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

http://sistemas.eel.usp.br/docentes/arquivos/2166002/1234Nb/Geetha-review2009.pdf

Ti based biomaterials, the ultimate choice for orthopaedic implants – A review

Metallic biomaterials are mainly used for replacing failed hard tissue. The main metallic biomaterials are stainless steels, Co-based alloys, and titanium and its alloys. Recently, titanium alloys are getting much attention for biomaterials. The various kinds of new high strength α+β and low-modulus β-type titanium alloys composed of nontoxic elements, such as Nb, Ta, Zr, etc., are developed for biomedical applications because of the toxicity of alloying elements and lack of mechanical biocompatibility of conventional titanium alloys, such as Ti-6Al-4V. Recent research and development in other metallic alloys, such as stainless steels and Co-based alloys, also will be discussed.

Recent metallic materials for biomedical applications

https://www.tpbin.com/Uploads/Subjects/643149a0-8194-4c67-bf05-73fae6f0d14f.pdf

Development of new metallic alloys for biomedical applications

Young's modulus as well as tensile strength, ductility, fatigue life, fretting fatigue life, wear properties, functionalities, etc., should be adjusted to levels that are suitable for structural biomaterials used in implants that replace hard tissue. These factors may be collectively referred to as mechanical biocompatibilities. In this paper, the following are described with regard to biomedical applications of titanium alloys: the Young's modulus, wear properties, notch fatigue strength, fatigue behaviour on relation to ageing treatment, improvement of fatigue strength, fatigue crack propagation resistance and ductility by the deformation-induced martensitic transformation of the unstable beta phase, and multifunctional deformation behaviours of titanium alloys.

Mechanical biocompatibilities of titanium alloys for biomedical applications.

The low rigidity type titanium alloy, Ti–29Nb–13Ta–4.6Zr was designed, and then the practical level ingot of the alloy was successfully fabricated by Levicast method. The mechanical and biological compatibilities of the alloys were investigated in this study. The following results were obtained. The mechanical performance of tensile properties and fatigue strength of the alloy are equal to or greater than those of conventional biomedical Ti–6Al–4V ELI. Young’s modulus of the alloy is much lower than that of Ti–6Al–4V ELI, and increases with the precipitation of α phase or ω phase in the β matrix phase. The compatibility of the alloy with bone of the alloy is excellent. Low rigidity of the alloy is effective to enhance the healing of bone fracture and remodeling of bone. The bioactive coating layer of hydroxyapatite can be formed on the alloy.

https://www.jstage.jst.go.jp/article/matertrans/43/12/43_12_2970/_pdf

Development of Low Rigidity β-type Titanium Alloy for Biomedical Applications

Corrosion resistance, wear resistance and biocompatibility of the studied Ti–Ta alloys with Ta contents of 10, 30 and 70 mass% together with the currently used metallic biomaterials pure titanium (Ti) and Ti–6Al–4V extra low interstitial (ELI) alloy were investigated for biomedical applications. Corrosion resistance was measured by an anodic polarization test using an automatic potentiostat in 5% HCl solution at 310 K. Wear resistance was evaluated using a pin-on-disk type friction wear test system with a load of 4.9 N at 310 K in a simulated body fluid (Ringer's solution), and biocompatibility was judged by evaluating the cyto-toxicity through MTT assay. The passive behaviors are observed for all the studied Ti–Ta alloys, and the TiO2 passive films strengthened by the more stable Ta2O5 passive films result in improved corrosion resistance of the studied Ti–Ta alloys with increasing Ta content. All the studied Ti–Ta alloys are non-cytotoxic like pure Ti. The crystal structure shows little influence on the corrosion resistance and cyto-toxicity of the studied Ti–Ta alloys. The experimental results conform the expected excellent corrosion resistance and biocompatibility of the studied Ti–Ta alloys, which are better than or similar to those of pure Ti or Ti–6Al–4V ELI alloy used as standard biomaterials, suggesting their promising potential for biomedical applications.

/pdf/corrosion-resistance-and-biocompatibility-of-ti-ta-alloys-8re5mvfpog.pdf

Corrosion resistance and biocompatibility of Ti-Ta alloys for biomedical applications

The low rigidity type titanium alloy, Ti-29Nb-13Ta-4.6Zr was designed, and then the practical level ingot of the alloy was successfully fabricated by Levicast method. The mechanical and biological compatibilities of the alloys were investigated in this study. The following results were obtained. The mechanical performance of tensile properties and fatigue strength of the alloy are equal to or greater than those of conventional biomedical Ti-6Al-4V ELI. Young's modulus of the alloy is much lower than that of Ti-6Al-4V ELI, and increases with the precipitation of a phase or ω phase in the β matrix phase. The compatibility of the alloy with bone of the alloy is excellent. Low rigidity of the alloy is effective to enhance the healing of bone fracture and remodeling of bone. The bioactive coating layer of hydroxyapatite can be formed on the alloy.

Hisao Fukui

Papers

Development of Low Rigidity β-type Titanium Alloy for Biomedical Applications

Corrosion resistance and biocompatibility of Ti-Ta alloys for biomedical applications

Development of low rigidity β-type titanium alloy for biomedical applications : Biomaterials and bioengineering

Improvement in fatigue characteristics of newly developed beta type titanium alloy for biomedical applications by thermo-mechanical treatments

Numerical simulation of canine retraction by sliding mechanics.