Surface morphology optimization for osseointegration of coated implants

This paper aims to establish a relationship between the surface morphology induced micromechanics and bone remodeling responses to a solid bead coated porous implant and further to develop a multiobjective optimization framework for the coating design of biomaterials. Multiscale modeling and remodeling techniques were developed, where a macroscopic analysis was initially performed to generate a global response to enable a microscopic analysis. The bone remodeling responses of the microscopic models (with a specific surface morphology) were evaluated in terms of the average apparent density developed in the peri-implant region. To explore the proposed multiscale analysis and design methods, a typical dental implantation setting is exemplified in this study. The response surface method (RSM) was utilized to relate the major implant coating parameters to the bone responses. It is found that increasing the volume fraction of the coating beads/particles results in a greater bone density, whereas increasing bead/particle size does not significantly affect the bone’s responses. Several different multiobjective optimization schemes were adopted to optimize the coated bead size and volume fraction, which reveal that the optimal design parameters of particle diameter and volume fraction are 100 μm – 35% and 38 μm – 17.5% for the cortical and cancellous bones respectively, agreeing with clinical data. To maximize the implant/bone interfacial stability, specific surface coating designs for particular locations are recommended.