From idea to patent: development of innovative biomedical material for dental implants

One of the main issues concerning dental, but also all other implants, arises from their Young’s modulus being considerably higher than that of bone. This can lead to stress shielding, bone resorption, and poor osseointegration of dental implants. Therefore, intensive activities are directed to lowering Ti implants Young’s modulus while preserving sufficient values of other mechanical properties. Most of them are oriented at β-type Ti alloys, but recently some other metal matrix composites appear as a possible solution. This presentation report on the development of the titanium-magnesium (Ti–Mg) bioactive metal- metal composite designed concretely for a fabrication of dental implants. The biomedical Ti-12vol. %Mg composite 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/cm3), while the mechanical strength of Ti Grade 4 is maintained (at values required for dental implants). 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 Ti-Mg implants equal to the one of the reference material. Exposure of as- extruded composite samples to Hank’s solution, realized 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, newly developed Ti-Mg composite shows improved mechanical compatibility (i.e., reduction of stress-shielding) and better osseointegration potential.