12 19 Focus 8

4-D printing is here, and it can help your dental practice!

Dec. 16, 2014
4-D printing will no doubt continue to change restorative dentistry as we know it. The concept of 4-D printing is based on the capability of printed material to alter itself under any circumstances without human control.
3-D printing has become very popular, as has the “maker movement.” The maker movement is the umbrella term for independent inventors, designers, and tinkerers. A convergence of computer hackers and traditional artisans, this niche group is established enough to have its own magazine, called “Make,” as well as the hands-on “Maker Faire.” This is a welcome event for those do-it-yourselfers who used to toil away in solitude. Makers tap into American self-reliance and combine that with open-source learning, contemporary design, and powerful personal technology such as 3-D printers. The creations stir the imaginations of consumers who have been numbed by generic, mass-produced, made-in–China merchandise.(1)

3-D printing has also hit dentistry. 3-D printing takes the productivity of digital design to the production stage. By combining oral scanning, CAD/CAM design, and 3-D printing, dental labs can accurately and rapidly produce crowns, bridges, stone models, and a range of orthodontic appliances. With a 3-D printer performing most of the work, dental labs reduce the holdup of manual modeling and the business can grow. For those eager for the day when everything from scheduling to finished restoration can be achieved digitally and automatically, the future is here.

First, a digital camera is placed in the mouth and a digital image of the area in question appears on the chairside computer screen. Design software is employed to fit a digital crown on a damaged tooth or other types of restorations. After adjustments are made digitally, the digital design of a new restoration is transferred to a CNC (computer numerical control) milling machine where the restoration is “printed.” 3-D printers deposit numerous layers of material to form the restoration from the foundation, and the CNC milling machine creates the desired restoration from a block of material. The restoration is then placed in the mouth. The ability to design and manufacture products in the dental office with 3-D printing is transforming how dentists conduct business.

Dentistry now has another option – 4-D printing! This will no doubt continue to change restorative dentistry as we know it. The concept of 4-D printing is based on the capability of printed material to alter itself under any circumstances without human control. Skylar Tibbits has developed a model and predicts that 4-D printing will soon replace 3-D printing in dentistry and beyond.(2)

Skylar Tibbits is the Self-Assembly Lab Director and a trained architect, computer scientist, and artist. His unique research focuses on developing self-assembly technologies for large-scale structures in the physical environment. The 4-D printing project is enabled by Stratasys’ Connex multi-material 3-D printing technology, with the added capability of embedded transformation from one shape to another directly off the 3-D printer.

4-D printed dental materials should be able to adjust to the situation and restoration needed, but they may not completely remove the need for human control. The oral environment is dynamic, yet the 4-D printed materials are new and still have restricted capacity. This technology is not yet commercially available. As environmental, economic, human, and other constraints continue to fluctuate, we will eventually need dynamic systems that can respond with ease and agility. 4-D printing responds to changes in the environment and offers a change to our comprehension of structures. Until now they have stayed static and rigid, but they will soon be dynamic, adaptable, and tunable for on-demand performance in many different conditions.

In order to understand 4-D, you must understand 3-D. 3-D printing is the opposite of CAD/CAM, which is a subtractive process of removing layers of material from a solid block of material. 3-D printing is an additive process of making a 3-D object of almost any shape from a digital image using an array of mediums, complete with color and moving parts. Laying down the materials in successive layers, the object is created from the inside out.(3)

3-D printers can be used to create virtually any object directly from a computer-aided design. There is a video that demonstrates how a Stratasys Objet Connex 3-D printer can produce six different sizes of adjustable wrenches – from 5 cm to 50 cm – all in one print run. All the wrenches contain fully-movable parts and require no assembly after printing. The wrenches are made of digital ABS material, which has the strength of ABS-grade engineering plastics.(4)

The future is bright!

Maria Perno Goldie, RDH, MS, is the editorial director of RDH eVillage FOCUS.

1. Voight J. Which Big Brands Are Courting the Maker Movement and Why, From Levis to Home Depot. Adweek. http://www.adweek.com/news/advertising-branding/which-big-brands-are-courting-maker-movement-and-why-156315.
2. http://www.stratasys.com/industries/education/4d-printing-project.
3. Sims A. Move over CAD/CAM, here comes 3-D Printing. Dental Economics. http://www.dentaleconomics.com/articles/print/volume-103/issue-4/features/move-over-cad-cam-here-comes-3-D-printing.html.
4. Printing – a Giant Wrench with a 3-D Printer. https://www.youtube.com/watch?v=WmDz7Q9_h6c.