Mechanical properties and cyto-toxicity of new beta type titanium alloy with low melting points for dental applications

Beta stabilized new alloys such as Ti-29Nb-13Zr-2Cr, Ti-29Nb-15Zr-1.5Fe, Ti-29Nb-10Zr-0.5Si, Ti-29Nb-10Zr-0.5Cr-0.5Fe and Ti-29Nb-18Zr-2Cr-0.5Si have been developed for dental applications. These alloys were designed based on master alloy Ti-29Nb-13Ta-4.6Zr (TNTZ) for biomedical applications. In this research, high melting temperature element Ta was replaced with beta stabilizing elements such as Cr, Fe and Si to lower the melting temperature of the alloy. Their melting points, mechanical properties, surface reaction layers and cyto-toxicity were investigated in this study. Melting points of designed alloys fall by about 50 K to 370 K as compared with that of TNTZ, and Ti-29Nb-13Zr-2Cr has the lowest melting point of around 2050 K. Vickers hardness of the surface of each designed alloy cast into modified magnesia based investment material is in the range of 400 Hv to 500 Hv, which is lower than that of TNTZ (around 560 Hv). Balances of strength and ductility of cast Ti-29Nb-13Zr-2Cr, Ti-29Nb-15Zr-1.5Fe and Ti-29Nb-10Zr-0.5Cr-0.5Fe are nearly equal to that of cast TNTZ. Cell viability of each cast designed alloy is excellent. (c) 2005 Elsevier B.V. All rights reserved.