Surface Modifications of cpTi and Ti-6Al‑4V: The Synergistic Potential of PEO-CaP for Optimized Dental Implant...

The surface characteristics of biomaterials are essential to the clinical performance of dental implants, as surface modifications directly affect their mechanical, electrochemical, and biological behavior. This study aimed to identify the most advantageous surface treatment-substrate combination, providing insights that support the development of more durable, bioactive, and clinically effective implant materials. Two surface modification techniques were investigated: sandblasting followed by double acid etching (SLA-like surfaces) and bioactive coatings enriched with calcium (Ca) and phosphorus (P) produced by plasma electrolytic oxidation (PEO-CaP), applied to commercially pure titanium (cpTi) and Ti-6Al-4V alloy. Polished discs of both substrates were divided into six groups (cpTi, Ti6Al4V, cpTi-SLA, Ti6Al4V-SLA, cpTi-PEO, and Ti6Al4V-PEO) and evaluated for their microstructural, mechanical, electrochemical, biological, and bioactive properties. Compared with cpTi, Ti-6Al-4V exhibited higher hardness and mechanical strength, whereas PEO coatings enhanced corrosion resistance by promoting the formation of anatase and rutile crystalline phases. SLA treatment resulted in roughened topographies with pronounced microdepressions, whereas PEO formed porous oxide layers enriched with Ca and P, which enhanced surface bioactivity and provided a more favorable substrate for osteoblastic differentiation compared with SLA. Notably, all tested surfaces induced hydroxyapatite formation, reinforcing their bioactive potential. Collectively, these findings indicate that PEO treatment, particularly on Ti-6Al-4V, provides a synergistic enhancement of mechanical robustness and corrosion resistance, supporting its potential as an effective surface modification strategy for dental implants.