Razi University

 AbstractTitanium dental implants are among the most widely used options for replacing missing teeth owing to their favorable biocompatibility, desirable mechanical properties, and adequate corrosion resistance. Nevertheless, the long-term success of dental implants depends not only on the bulk properties of the material but also on the complex interactions among the implant surface, surrounding bone tissue, and the microbial environment, which play a decisive role in the establishment and long-term stability of osseointegration. Accordingly, the development of engineered surfaces capable of simultaneously providing favorable biological and functional properties has emerged as an important research direction in the field of titanium-based dental implants.In the present study, the spatial architecture of nanostructures was considered the central design parameter. The objective was to design and investigate a hybrid architecture comprising TiO? nanotube arrays and ZnO nanorods, with the aim of promoting ZnO nucleation and growth from within the TiO? nanotube channels and directing the nanorods along the longitudinal axes of the nanotubes, to the extent possible. To this end, titanium sheets were cut, polished, and cleaned before being converted into TiO? nanotube arrays by electrochemical anodization in an acidic electrolyte containing hydrofluoric acid (HF) and acetic acid under a constant applied potential at room temperature. Subsequent heat treatment was performed to promote the formation and stabilization of the anatase phase of titanium dioxide.In the next stage, vacuum-assisted seed loading was employed to increase the likelihood of precursor solution penetration into the internal spaces of the nanotubes. For this purpose, a custom-designed and fabricated vacuum chamber was used. A solution containing a zinc precursor was introduced into the nanotubular structure under controlled conditions, and the seed-loading procedure was repeated over multiple cycles. Subsequently, ZnO nanorods were grown using a hydrothermal method, with particular attention given to the effects of growth conditions on nanostructure formation and morphological evolution.Structural and morphological characterization of the samples was performed using field-emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffraction (XRD). The results indicated the formation of a hierarchical TiO?/ZnO structure, with ZnO nanorods observed both within and on the surface of the TiO? nanotube arrays. Furthermore, the findings revealed that hydrothermal growth parameters and the seed-loading method directly influenced nanorod morphology, density, and dimensions. Phase analysis also confirmed the formation of the expected crystalline structure.The findings of this study provide a practical basis for controlling the hierarchical architecture of ZnO nanostructures on titanium surfaces. This approach may serve as a foundation for further investigations into osseointegration, biocompatibility, and antibacterial performance, with the ultimate aim of developing surface-engineered titanium dental implants.Keywords: TiO? nanotubes; ZnO nanorods; hybrid architecture; vacuum-assisted seed loading; hydrothermal growth; surface engineering; osseointegration.