Preparation of a Novel Transplant Material, Zirconium Oxide (ZrO₂) Nanotubes, and Characterizations Research

BACKGROUND Zirconia is one of the most widely used ceramic materials for transplanting and treating caries. This study aimed to synthesize zirconium oxide (ZrO₂) nanotubes and evaluated their characteristics. MATERIAL AND METHODS Zr film was prepared using an ion plating method. Nanoarray film was constructed with anodizing. Photocatalytic properties of nnanotubes were assessed by evaluating decolorization of methyl orange. Elemental analysis and structural morphology for coatings were evaluated using x-ray analysis and scanning electron microscopy (SEM). Dimensions for layers were measured with SEM imaging. X-ray diffraction (XRD) was measured using Empyrean x-ray diffractometry. RESULTS There were irregular cavities on the surface of ZrO₂ nanotubes undergoing anodizing of 30V. Anodizing voltage of 45 V (with regular nano-pore arrays and smooth nanotube walls) and anodic oxidation duration of 60 min (ZrO₂ nanotubes clearly formed atop ZrO₂-coated substrate surface) were the optimal condition for ZrO₂ nanotube formation. TEM illustrated tube length of ZrO₂ nanotubes was approximately 2.01 μm. Nanotube diameter was 51.06 nm, and wall thickness was 13 to 14 nm. Annealed nanotubes showed an obvious crystal diffraction pattern. TEM diffraction ring showed nanotube array without obvious transistor structure before annealing, but with good crystallinity post-annealing. Increased annealing temperatures result in enhanced intensity for the monoclinic phase (400-800°C). After annealing at 600°C, the decolorization effect of ZrO₂ nanotubes on methyl orange was better than that post-annealing at 400 and 800°C. ZrO₂ nanotubes demonstrated higher microshear bond strength. CONCLUSIONS Zirconium nanotubes were successfully synthesized and demonstrated good structural characteristics, which can be applied to transplanting and treating caries.