Titanium-magnesium composite for dental implants (BIACOM)

Abstract

We report on the study on the titanium-magnesium (Ti–Mg) bioactive metal-metal composite utilized for a fabrication of dental implants. The biomedical Ti-12vol.%Mg composite, named BIACOM, is manufactured using a cost effective approach, where a mixture of elemental Ti and Mg powders is extruded at low temperature to sound profiles. Microstructure of composite comprises filaments of biodegradable Mg component, which are arrayed along extrusion direction and are homogenously distributed within permanent, bioinert Ti matrix. Compared to Ti Grade 4, the reference material used for dental implants, the properties of as-extruded composite include significantly reduced Young’s elastic modulus (92.1 GPa) and low density (4.12 g.cm−3), while the mechanical strength of Ti Grade 4 is maintained. Dynamic testing of dental implants fabricated from as-extruded composite, realized to follow the ISO 14801 standard for endosseous dental implants, confirms fatigue performance of BIACOM implants equal to the one of the reference material. Exposure of as-extruded composite samples to Hank’s solution, realized in order to simulate behavior in human body over the time after implantation, yields gradual dilution of Mg from composites surface and volume. Corroded Mg leaves at prior Mg filament sites pores within Ti matrix, which remains intact. This provides further decrease of Young’s modulus and enhances macro and micro roughness at implants surface. As a result, BIACOM shows improved mechanical compatibility (i.e., reduction of stress-shielding) and better osseointegration potential.