From Three-Dimensional (3D)- to 6D-Printing Technology in Orthopedics: Science Fiction or Scientific Reality?

Abstract

Over the past three decades, additive manufacturing has changed from an innovative technology to an increasingly accessible tool in all aspects of different medical practices, including orthopedics. Although 3D-printing technology offers a relatively inexpensive, rapid and less risky route of manufacturing, it is still quite limited for the fabrication of more complex objects. Over the last few years, stable 3D-printed objects have been converted to smart objects or implants using novel 4D-printing systems. Four-dimensional printing is an advanced process that creates the final object by adding smart materials. Human bones are curved along their axes, a morphological characteristic that augments the mechanical strain caused by external forces. Instead of the three axes used in 4D printing, 5D-printing technology uses five axes, creating curved and more complex objects. Nowadays, 6D-printing technology marries the concepts of 4D- and 5D-printing technology to produce objects that change shape over time in response to external stimuli. In future research, it is obvious that printing technology will include a combination of multi-dimensional printing technology and smart materials. Multi-dimensional additive manufacturing technology will drive the printing dimension to higher levels of structural freedom and printing efficacy, offering promising properties for various orthopedic applications.

4D food printing technology: Structural changes to culinary art and beyond

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Application of 3D, 4D, 5D, and 6D bioprinting in cancer research: what does the future look like?

“…The advent of 6D printing represents a significant evolution in additive manufacturing technologies. This innovative approach seeks to merge the capabilities of both 4D and 5D printing to create advanced biomaterials capable of responding to extrinsic stimuli and modify shape with time, 163 though it remains largely theoretical at this stage due to practical challenges. 29 This technology holds the potential to construct structures with added dimensions like topology and texture, thereby significantly improving the mechanical, biological, and physical properties of printed tissues.…”

Use of Biomaterials in 3D Printing as a Solution to Microbial Infections in Arthroplasty and Osseous Reconstruction

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