Characteristics and osteogenic effect of nanostructure-coated zirconiaimplant

Objectives: To evaluate the properties and osteogenic effects of zirconia implant coated with tantalum nanostructure.
Methods: 60 Zirconia discs were cutand sinteredto be 10mm in diameter and 1.5mm in thickness.The samples were divided into 2 groups:ZrO₂and ZrO₂/TNS.The tantalum lay was fabricated by magnetron sputtering and tantalum nanostructure (TNS) was formed using an electrochemical anodization in an electrolyte comprised of H₂SO₄, HF and water.The surface characteristics were detected by FESEM,EDX,AFM and the water contact angle.The osteogenic effect of MC3T3-E1 cells was assessed via MTT assay ,fluorescence microscopy, PCRand ALP activity test.
Results: The SEM and EDX profies showed tantalum nanostructure （2um in thickness）with pitand foveae were formed on zirconia substrate after magnetron sputtering and anodization.The AFM revealed the roughness of ZrO2/TNS were higher than ZrO2. Compared to ZrO2, anodized Ti–ZrO2 samples are able to maintain their surface wettability to less than 30°.The cell proliferation on ZrO2/TNS appeared significantly higher in comparison to the control groups after 3 and 5 days(p<.05).Additionally, fluorescence microscopyshowed a significantly high cell adhesion for ZrO2/TNT surface as compared to ZrO2 after 72h(p<.05). The ZrO2/TNS had greater ALP activities after 7 and 14 days(p<.05). The mRNA level of osteocalcin was higheron theZrO2/TNSthannon-coated zirconia after 14 days(p<.05).
Conclusions: The tantalum nanostructure were successfully fabricated on zirconia substrate by magnetron sputtering and anodization.The tantalum nanostructure significantly enhanced the activity of osteoblast cell on zirconia implant.