Fabrication and characterization of Ti–12Mo/xAl2O3 bio-inert composite for dental prosthetic applications

Titanium-based alloys are standard for dental and orthopedic implants, but traditional options like Ti-6Al-4V have faced scrutiny regarding the potential toxicity of aluminum and vanadium ions. Researchers are increasingly turning toward beta-type titanium alloys, which use non-toxic stabilizers like molybdenum (Mo). This study investigates the fabrication and performance of a new Ti-12Mo composite reinforced with alumina (Al2O3) nanoparticles, aiming to improve mechanical strength, wear resistance, and bio-inertness for dental prosthetic applications.

The researchers employed powder metallurgy techniques to prepare Ti-12Mo composites reinforced with varying concentrations of alumina nanoparticles (0, 5, 10, and 15 wt%). The materials were processed through mechanical milling under an argon atmosphere, followed by cold pressing and sintering at 1,450°C. The study evaluated the resulting samples through density measurements, Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Vickers hardness testing, pin-on-ring wear testing, and electrochemical corrosion analysis in simulated artificial saliva.

The researchers found that 5 wt% alumina was the optimal reinforcement level. This composition achieved a Vickers hardness of 593.4 HV, an 85% increase over pure titanium (320 HV). Furthermore, it exhibited the lowest wear rate (0.0367 mg/min) and superior corrosion resistance in artificial saliva compared to both pure titanium and the non-reinforced Ti-12Mo alloy. Higher alumina concentrations (10-15 wt%) resulted in nanoparticle agglomeration and the formation of pores, which compromised the mechanical and electrochemical performance. Notably, ion release levels for all reinforced samples remained within safe, non-toxic limits for biological applications.

This research offers a viable pathway for developing high-performance, bio-inert dental materials that replace potentially harmful alloying elements with more biocompatible alternatives. By optimizing the sintering temperature and the ratio of ceramic reinforcement to the metallic matrix, the study demonstrates that it is possible to tailor these nanocomposites to meet the rigorous physical and chemical demands of dental prosthetics.