Development of Individual Three-Dimensional Bone Substitutes Using “Selective Laser Melting”

Abstract

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.

Induction of Osteogenic Differentiation of Adipose Derived Stem Cells by Microstructured Nitinol Actuator-Mediated Mechanical Stress

“…Hollander et al oberserved similar cell morphology of human primary osteoblast like cells from the iliac crest on TiAl6V4 discs processed by SLM. The vitality was comparable to flat TiAl6V4 discs, but cell density on SLM surfaces was clearly increased [25]. We also found high rates of life cells on SLM-NiTi surfaces comparable to flat glass or NiTi and an enhanced dimensional growth.…”

The biocompatibility of dense and porous Nickel–Titanium produced by selective laser melting

“…Materials Science and Engineering C 33 (2013) 419-426 By building up material by adding layers instead of removing material, they offer a nearly unlimited flexibility of the part's geometry and complexity. AM, therefore, has a high potential for the production of scaffolds, individual bone substitutes and implants [9,10]. While NiTi-SMA are gaining interest for both engineering applications and for medical applications, AM of NiTi has received less attention so far.…”

“…Generally, the production of single parts, e.g., individual implants, is challenging. In recent years, additive manufacturing (AM) has established promising methods for medical applications [9,10]. These laser assisted freeform fabrication methods provide special opportunities due to their use of the additive operation principle.…”

X-ray computed tomography and additive manufacturing in medicine: a review

“…Three reviews were produced during this time that identified this technique as a viable method for production of scaffolds, as well as of prostheses and tissue models [29][30][31]. In 2003, Hollander et al [32] performed preliminary studies using XCT with SLM for the purpose of directly replacing bone using TiAl6V4 implants. The authors observed that SLM implants showed increased biocompatibility in the form of greater metabolic activity of osteoblasts when compared to non-SLM control implants, which the authors attributed to the increased surface area of SLM implants.…”