Multiscale design of porous implants with a biomimetic functionally graded cellular material
Endosseous implants are now widely used in clinical practice to restore joint functionality or to replace missing teeth. Despite their increasing success, implant long-term stability remains a concern and it is difficult to predict the surgical outcome so far. A major cause of failure comes from bone resorption secondary to stress shielding, which arises from the mismatch of the mechanical properties between the implant and the surrounding bone tissue. To overcome this problem, MIDPOINT proposes to design porous implants that will have a biomimetic cancellous bone microstructure with a nonhomogeneous distribution of its material properties. The optimal design will produce implants with mechanical and microstructural properties similar to that of the bone, which will result in an improvement of the effectiveness of osseointegration phenomena.
A work methodology that combines multiscale computational modelling and experimental work for the formulation, construction, verification and validation of computational models is proposed. This methodology will comprise i) the design of new biomimetic microstructures that replicate the geometrical properties of the natural trabecular bone using a generative design approach, the Voronoi tessellation approach; ii) the development of an iterative computational method to predict the fatigue life of the artificial microstructures directly at the macroscale employing damage accumulation models coupled with artificial neural networks; and iii) the construction of multiscale models of bone-implant systems to optimize the implant microstructure locally in order to achieve a desirable mechanical response and functional environment for bone ingrowth and, therefore, minimize bone resorption. These techniques will be employed to design implants and scaffolds that, together with medical imaging techniques, can be personalized to the needs of each patient and directly printed at the medical institution using additive manufacturing techniques.