Mechanical and clinical properties of titanium and titanium-based alloys (Ti G2, Ti G4 cold worked nanostructured and Ti G5) for biomedical applications

Commercially pure titanium (Ti G2 and Ti G4) and the Ti-6Al-4V (Ti G5) alloy have limitations for biomedical applications, due to either low mechanical strength (Ti G2, Ti G4) or the possible release of toxic ions (Ti G5). Since Ti alloys have a low hardening coefficient, it is very difficult to improve their mechanical properties by work hardening. The purpose of this work was to compare the mechanical and clinical properties of Ti G4 nanostructured after severe plastic deformation by ECAP (Ti G4 Hard) with those of Ti G2, Ti G4 and Ti G5. Bars, disks and dental implants made with Ti G2, Ti G4, Ti G5 and Ti G4 Hard were tested. Mechanical tests (tension, compression, hardness, elastic modulus, fatigue and torque) and roughness measurements were performed. The results of the mechanical tests showed that Ti G4 Hard has a higher mechanical strength and a lower elastic modulus than Ti G2, Ti G4 and Ti G5. Scanning electron microscopy and roughness measurements results showed that acid etched Ti G4 Hard nanostructured has better surface morphological features than Ti G2, Ti G4 and Ti G5. The clinical performances of Ti G4 and Ti G4 Hard were similar. The high mechanical strength of Ti G4 Hard means that it can be used to replace Ti G5 in several clinical applications, with the advantage of not releasing toxic ions. The Ti G4 Hard dental implants have adequate mechanical properties and can be inserted in areas with low bone volume. (C) 2018 Brazilian Metallurgical, Materials and Mining Association. Published by Elsevier Editora Ltda.