치과용 임플란트를 위한 저 탄성계수 및 자기민감성을 갖는 지르코늄기 합금 연구

Abstract

Today, metallic materials have good bio-mechanical properties and suitability for general sterilization processes in the bio-materials industry, and they have a great influence on the field of bio-materials because they have superior mechanical properties compared to other materials. Research on these bio-materials has received great interest worldwide, and various implant bio-materials such as bone, tooth substituting metals, ceramics and polymer materials have been studied. In particular, metallic bio-materials should be carefully selected taking into consideration the composition of bio-materials that can avoid or minimize adverse effects through research into biological behavior. Representative metal bio-materials include pure Ti, Ti-6l-4V, stainless steel, and Co-Cr alloys. However, despite considerable clinical successes, various factors, such as stress shielding, image distortion during MRI diagnosis, cytotoxicity, fatigue fracture and corrosion, have undesirable effects on actual performance. Therefore, zirconium based bio-material has attracted great interest to solve the above problems. The purpose of this study is to investigate the potential use of zirconium-based alloys as bio-materials to neutralize magnetic properties for magnetic resonance imaging and to prevent the stress shielding effect caused by the difference in elastic modulus between implant materials and natural bone. The Zircaloy4-xCu alloys, Zr-xCu and Zr-xSi binary alloys, were prepared using the arc-melting process with Zircaloy4, pure zirconium strips and oxygen-free copper, silicon respectively. Zircaloy4-xCu and Zr-xCu binary alloys has two dominant phases consisting of a-Zr and Zr2Cu intermetallic phase. and Zr-xSi binary alloys has two dominant phases consisting of a-Zr and Zr2Si intermetallic phase. The magnetic susceptibility of the zirconium-based alloys was extremely low, approximately 10-7; this level is approximately one order less than that of pure Zr and other commercialized metallic bio-materials. The elastic modulus of the Zirconium-based alloys were generally low value of 16-33GPa; that is similar to the value of natural bone. As a result it is possible to overcome the stress shielding effect and nullify the image distortion of MRI imaging. Consequently, Zirconium-based alloys have the potential to be used as bio-materials with low magnetic susceptibility and excellent mechanical properties.