응력차폐 개선을 위한 저탄성계수를 갖는 Zr-xCu/Zr-xSi 합금 연구

Abstract

The objective of this study is to fabricate Zr-xCu and Zr-xSi alloys with low elastic modulus for improving bone resorption in dental biomaterials. Metallic biomaterials are widely used for orthopaedic and dental applications due to their superior characteristics of mechanical properties and biocompatibility in order to prevent an allergic reaction to the metals. Metal alloys have played a predominant role as structural biomaterials in reconstructive surgery, orthopaedics, and non-osseous tissues. Most of all, the dental alloys for dental applications require a high corrosion resistance because the pH and temperature vary widely in the oral environment. Many metals and alloys, such as stainless steel, Co-Cr alloys, and Ti-based alloys are commonly used. Among these dental alloys, pure Ti and Ti-6Al-4V alloy have become the most popular metals used for the endosseous parts implants, bone plates, and artificial joints because they have excellent corrosion resistance and high biocompatibility with natural bone. Stress shield effect results in the reduction in bone density as a result of the removal of typical stress from the bone by an implant. In general, the bone in a healthy person will remodel in response to the loads it is placed under. Therefore, if the loading on a bone decreases, the bone will become less dense and weaker because there is no stimulus for continued remodeling that is required to maintain bone mass. Although Ti-based alloys have been widely used as implant components and devices, its elastic modulus (110 GPa) is much higher than that of natural human bone (10-30 GPa). Serious damage may be easily caused in the human body when the modulus of implant materials does not match the natural bone due to the stress shielding effects. Therefore, in recent, persistent efforts have been done to obtain biological hard tissue materials with low elastic modulus to transfer stress to the surrounding bones effectively. The Zr-xCu binary alloy exhibited moderate compressive strength (1291-1411 MPa), yield stress (517-552 MPa), favorable elongation (16.4-42.9%), elastic energy (6.76-7.43 MJ/m3) and low elastic modulus (18.5-23.1 GPa). The Zr-xSi binary alloy exhibited high compressive strength (1105-1623 MPa), yield stress (673-1514 MPa), favorable elongation (6-27.2%), high elastic energy (10.2-34.6 MJ/m3) and low elastic modulus (22.3-33.1 GPa). Consequently, Zr-xCu and Zr-xSi binary alloys have the potential to be used as biomaterials with nullifying stress shielding effects for biological hard tissue materials