Improved biological performance of microarc-oxidized low-modulus Ti-24Nb-4Zr-7.9Sn alloy

Ti-24Nb-4Zr-7.9Sn (TNZS) is a newly developed beta-titanium alloy with low modulus and it has been considered as good material for dental or orthopedic implant. The purpose of the current study is to evaluate the effect of micro-arc oxidation (MAO) treatment on the biological performance of TNZS surface. The phases, morphology and chemical composition of the MAO-treated surface were characterized by X-ray diffraction, energy dispersive spectroscope and scanning electron microscopy analysis respectively. Then we tested the biocompatibility by examining the cell morphology and viability of osteoblast cells growing on MAO-TNZS surface. The bone binding strength of the specimens was evaluated by removal torque test after implantation in rabbit tibiae for 6 weeks. Compared with the none-treated titanium and TNZS specimens, MAO treated TNZS specimens showed a significant increase (p<0.05) in hydrophilicity, roughness, cell viability and removal torque forces. In summary, MAO treatment helps to form a porous surface with a biologically active bone-like apatite layer on TNZS specimens, which may improve the biological response of MAO-TNZS implants.