Unlike conventional materials removal methods, additive manufacturing (AM) is based on a novel materials incremental manufacturing philosophy. Additive manufacturing implies layer by layer shaping and consolidation of powder feedstock to arbitrary configurations, normally using a computer controlled laser. The current development focus of AM is to produce complex shaped functional metallic components, including metals, alloys and metal matrix composites (MMCs), to meet demanding requirements from aerospace, defence, automotive and biomedical industries. Laser sintering (LS), laser melting (LM) and laser metal deposition (LMD) are presently regarded as the three most versatile AM processes. Laser based AM processes generally have a complex non-equilibrium physical and chemical metallurgical nature, which is material and process dependent. The influence of material characteristics and processing conditions on metallurgical mechanisms and resultant microstructural and mechanical properties of AM proc...

Laser additive manufacturing of metallic components: materials, processes and mechanisms

Topological design and additive manufacturing of porous metals for bone scaffolds and orthopaedic implants: A review.

3D Printing promises to produce complex biomedical devices according to computer design using patient-specific anatomical data. Since its initial use as pre-surgical visualization models and tooling molds, 3D Printing has slowly evolved to create one-of-a-kind devices, implants, scaffolds for tissue engineering, diagnostic platforms, and drug delivery systems. Fueled by the recent explosion in public interest and access to affordable printers, there is renewed interest to combine stem cells with custom 3D scaffolds for personalized regenerative medicine. Before 3D Printing can be used routinely for the regeneration of complex tissues (e.g. bone, cartilage, muscles, vessels, nerves in the craniomaxillofacial complex), and complex organs with intricate 3D microarchitecture (e.g. liver, lymphoid organs), several technological limitations must be addressed. In this review, the major materials and technology advances within the last five years for each of the common 3D Printing technologies (Three Dimensional Printing, Fused Deposition Modeling, Selective Laser Sintering, Stereolithography, and 3D Plotting/Direct-Write/Bioprinting) are described. Examples are highlighted to illustrate progress of each technology in tissue engineering, and key limitations are identified to motivate future research and advance this fascinating field of advanced manufacturing.

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Recent advances in 3D printing of biomaterials

The future of dental devices is digital.

Densification behavior, microstructure evolution, and wear performance of selective laser melting processed commercially pure titanium

Bioactive Ti metal analogous to human cancellous bone: Fabrication by selective laser melting and chemical treatments.

Osteoinduction of porous Ti implants with a channel structure fabricated by selective laser melting

Porous titanium (Ti) metal with a structure similar to that of human cancellous bone was fabricated by selective laser melting (SLM) process. SEM observation showed that the core part of the walls of the porous body was completely melted by the laser beam and weakly bonded with small Ti particles on its surface. These Ti particles were joined with the core part by heating above 1000 Â°C, with remaining micro cavities on their surfaces. Tensile strength of the as-prepared solid rod was 530MPa and gradually decreased with increasing temperatures to 400MPa at 1300 Â°C, whereas its ductility increased with increasing temperatures. NaOH treatment formed fine network structure of sodium hydrogen titanate (SHT) on the walls of the porous Ti metal. The SHT was transformed into hydrogen titanates by HCl treatment and finally anatase and rutile by the heat treatment. Thus treated porous Ti metal formed apatite on its surface in simulated body fluid (SBF) within 3 days.

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Fabrication of Bioactive Porous Ti Metal with Structure Similar to Human Cancellous Bone by Selective Laser Melting

In the present study, to evaluate the effect of pore size on bone ingrowth, we fabricated lotus stem-type titanium implants each with 4 square holes (diagonal length: 500, 600, 900 and 1200 μm) by using the rapid prototyping process with selective laser melting. These were then subjected to chemical and heat treatments to induce bioactivity. There were significant differences between bone ingrowth on the bioactive-treated and untreated implants. There were no significant differences for bone ingrowth among all holes in both implants. However, in both implants, the 1200-μm was found to be the best for bone invasion in the early stages of growth. On the other hand, both 500and 600-μm were found to be suitable for bone ingrowth from 6 weeks to 26 weeks in treated implants. Thus, the simple architecture of the implants allowed effective investigation of the influence of the interconnective pore size on osteconduction.

N. Nishida

Papers

Bioactive Ti metal analogous to human cancellous bone: Fabrication by selective laser melting and chemical treatments.

Osteoinduction of porous Ti implants with a channel structure fabricated by selective laser melting

Fabrication of Bioactive Porous Ti Metal with Structure Similar to Human Cancellous Bone by Selective Laser Melting

Bone Ingrowth into Pores of Lotus Stem-Type Bioactive Titanium Implants Fabricated Using Rapid Prototyping Technique