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Integrated image-based design and solid free-form fabrication can create scaffolds that attain desired elasticity and permeability while fitting any 3D craniofacial defect. The scaffolds could be manufactured from degradable polymers, calcium phosphate ceramics and titanium. The designed scaffolds supported significant bone regeneration for all pore sizes ranging from 300 to 1200 microns. These results suggest that designed scaffolds are clinically applicable for complex craniofacial reconstruction.

A topology optimized lumbar interbody fusion cage was made of Ti-Al6-V4 alloy by the rapid prototyping process of selective laser melting (SLM) to reproduce designed microstructure features. Radiographic characterizations and the mechanical properties were investigated to determine how the structural characteristics of the fabricated cage were reproduced from design characteristics using micro-computed tomography scanning. The mechanical modulus of the designed cage was also measured to compare with tantalum, a widely used porous metal. The designed microstructures can be clearly seen in the micrographs of the micro-CT and scanning electron microscopy examinations, showing the SLM process can reproduce intricate microscopic features from the original designs. No imaging artifacts from micro-CT were found. The average compressive modulus of the tested caged was 2.97+/-0.90 GPa, which is comparable with the reported porous tantalum modulus of 3 GPa and falls between that of cortical bone (15 GPa) and trabecular bone (0.1-0.5 GPa). The new porous Ti-6Al-4V optimal-structure cage fabricated by SLM process gave consistent mechanical properties without artifactual distortion in the imaging modalities and thus it can be a promising alternative as a porous implant for spine fusion.

Aim and Background: Scientific approach is the utilization of the new generative manufacturing process termed Selective Laser Melting (SLM) for the creation of biocompatible three-dimensional (3-D) bone substitutes made of the titanium alloy TiAl6V4. The SLM technique enables direct transfer of virtual 3-D structures into solid metal materials with full serial characteristics and typically great freedom of geometric design. Material and Methods: Individual 3-D CAD data which are derived from computed tomography models of anatomic structures are subdivided into layers of defined thickness. The actual part is generated by a repeating process of applying TiAl6V4 powder in layers of 0.003-0.1 mm on the process chamber platform transferring the area and contour information of each layer into the material using a laser beam. The physical process is a complete remelting of the powder with a metallurgical bonding between the layers yielding densities of approximately 100%. This operation is repeated step by step until the generation of the 3-D part is completed. We cultured human primary osteoblast-like cells on different surfaces of SLMmanufactured TiAl6V4 parts to prove osteoblast compatibility. Proliferation, vitality, and alkaline phosphatase (AP) activity of osteoblast cultures are presented. Results: It has become possible to produce complex 3-D geometries with different surface properties within few hours. Compatibility of the tested TiAl6V4 material with human osteoblasts is demonstrated. The cultured cells attach and proliferate on SLM substrates and show AP activity. Conclusions:The presented results demonstrate the potential offered by the SLM process. On the basis of scanned information, the generation of complex anatomic structures is realizable. The presented promising advantages make this procedure interesting for the production of individual implants or bone substitutes.

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