Bioactive surface modification of Ti-29Nb-13Ta-4.6Zr alloy through alkali solution treatments

Area of Science:

• Biomaterials Science
• Surface Engineering
• Biocompatibility

Background:

• Titanium alloys are crucial for orthopedic implants due to their biocompatibility.
• Surface modification is key to improving the bioactivity and osseointegration of titanium implants.
• Ti-29Nb-13Ta-4.6Zr alloy (TNTZ) is a promising candidate for biomedical applications.

Purpose of the Study:

• To investigate the effect of different alkali treatments on the surface properties of TNTZ.
• To evaluate the bioactivity of modified TNTZ surfaces using simulated body fluid (SBF) tests.
• To correlate surface morphology and composition with apatite induction capability.

Main Methods:

• TNTZ alloy samples were treated using electrochemical (E), hydrothermal (H), and hydrothermal-electrochemical (HE) processes.
• Surface morphology was analyzed using electron microscopy.
• Bioactivity was assessed by immersion in simulated body fluid (SBF) to observe apatite formation.

Main Results:

• All treatments formed sodium-contained amorphous titanium oxide layers on TNTZ.
• Surface morphology varied from flat (E) to smooth mesh-like (H) to rough mesh-like (HE).
• Apatite formation in SBF increased with surface roughness, with HE > H > E.
• Lower niobium content on the surface correlated with enhanced apatite induction.

Conclusions:

• Alkali treatments effectively modify the TNTZ surface, creating bioactive titanium oxide layers.
• Surface roughness and reduced niobium content are critical factors for enhanced apatite induction.
• The hydrothermal-electrochemical (HE) process yields the most bioactive TNTZ surface for potential orthopedic applications.