Method: Ti-Zr alloy (Zr: 10-90 at.%) specimens were prepared by arc-melting in argon atmosphere. Constitutional phase was analyzed by X-ray diffractometer. Hardness was measured by Vickers indentation (n=10) with load (1.961N, 15s). Tensile test was evaluated from stress-strain curve generated by Instron-universal-testing machine. Osteogenic-MCT3T-E1 cells were cultured on specimen discs. Initial cell attachment (4-hr, 24-hr; n=3) was evaluated by WST-8-based-colorimetry; cell spread was assessed by ImageJ-morphology analysis (n=9), and cell differentiation is analyzed by ALP assay (day-7, day-12; n=3).
Result: Compared to Ti, Vickers hardness for Ti30Zr is 2.35 times significant higher (ANOVA, Tukey’s, F(10,154)=3.299, p<0.05). Ti30Zr also exhibits highest ultimate-tensile-strength (980MPa) compared to Ti (345MPa). No significant difference detected on number of cell attachment at 4-hr assay, but significantly increase after 24-hr culturing by 13% and 22% respectively for Ti and Ti10Zr to Ti50Zr (ANOVA, Tukey’s, F(5,12)=5.436, p<0.05). Largest cell size was detected on Ti10Zr, and significant larger than Ti50Zr and Ti70Zr (ANOVA, Tukey’s, F(5,48)=3.344, p<0.05). While ALP assay has no significant difference at day-7, significant decrease for Ti to Ti50Zr is detected on day-12 (ANOVA, Tukey’s, F(5,12)=3.749, p<0.05).
Conclusion: It is concluded Ti alloyed with Zr can provide improved mechanical properties with equivalent if not better biocompatibility, but cell activity seems to decrease while Zr concentration increase more than 50at.%.