Density functional theory insight into the role of Al and V in Ti-6Al-4V dental implants: structural, electronic, and mechanical properties.

Commercially pure titanium and Ti-6Al-4V are the most commonly used materials for dental implants owing to their balanced mechanical properties and biocompatibility. However, much of the related research has focused primarily on experimental synthesis, lacking theoretical guidance and a deeper understanding of the underlying mechanical differences. To address this, we employ density functional theory (DFT) and the special quasi-random structure (SQS) method to construct a 64-atom supercell model and systematically analyze the effects of Al (α-phase stabilizer) and V (β-phase stabilizer) on the structural, electronic, and mechanical properties of Ti-Al-V alloys with various compositions. The results show that Al stabilizes the α-phase by reducing the formation energy through significant charge transfer, whereas V promotes β-phase formation due to its inherent body-centered cubic (BCC) phase tendency. Electronic structure analysis revealed that Al enhances stability through s/p orbital hybridization at deep energy levels, whereas V's d-electrons dominate interactions near the Fermi level, weakening the bond strength. The moderate elastic modulus of α + β Ti-6Al-4V, combined with its structural isotropy and enhanced stability, results in superior tensile and yield strengths. On the basis of mechanistic insights from Ti-6Al-4V, potential alternative alloys suitable for dental implant applications are proposed.