Polydopamine coating in Ti and TiO2 nanotubes and its potential use in commercial biomedical implants: surface characterization and corrosion resistance in a physiological solution

Purpose Titanium and its alloys are widely used in dental implants; however, localized corrosion and metal ion release in the oral environment may compromise their long-term performance. This study aims to evaluate the effectiveness of polydopamine coatings deposited on commercially pure Ti and TiO2 nanotubes to enhance corrosion resistance and surface properties under physiological conditions. Design/methodology/approach Polydopamine coatings were deposited via oxidative polymerization of dopamine in a Tris buffer solution (pH 8.5). The coatings were characterized using Fourier transform infrared spectroscopy and Ultraviolet-visible spectroscopy, scanning electron microscopy, atomic force microscopy and water contact angle measurements. Corrosion behavior was assessed through electrochemical testing in Hank’s solution. Findings Uniform and adherent polydopamine coatings were successfully formed on Ti and TiO2 nanotubes, with thicknesses reaching 1585 ± 137 nm after 24 h. Electrochemical results showed a significant improvement in corrosion resistance, with corrosion current density reduced from 3.73 to 0.36 µA/cm2 for Ti and from 6.64 to 0.31 µA/cm2 for TiO2 nanotubes. Polydopamine coatings also enhanced surface hydrophilicity. Practical implications Polydopamine coatings offer a simple, biocompatible and effective strategy to improve the durability and clinical performance of titanium dental implants. Originality/value This study presents a systematic evaluation of polydopamine coatings on both flat and nanostructured titanium surfaces, demonstrating their synergistic interaction with TiO2 nanotubes in enhancing corrosion resistance under simulated physiological conditions. Furthermore, the coating process is successfully reproduced on commercial dental implants, highlighting its practical applicability for real clinical devices.