3D printing has had a major impact on the way in which many manufacturing industries in the world have set up their production processes or will set them up in the near future. But what is 3D printing and how does it actually work?
All 3D printing techniques are based on the general term ‘additive manufacturing (AM). This Computer-Aided Manufacturing (CAM) technology is based on building up a product layer by layer from a material. This creates a stacked layer of material that, when built up as a whole, embodies a product. In nature, we see this in sediment layers in rock. With 3D printing technology, the construction of the product is not controlled by nature, but by software.
3D printing technology in dentistry
What could we make in dentistry with 3D printing technology? Basically, almost everything we use in dentistry. After all, 3D printing is the ideal technology to produce products with high precision in a limited edition and preferably in a limited time. That is dentistry all the way. This includes crowns and bridges, the metal base for frames, aligners, models, drilling templates for oral implantology, temporary provisions, but also dentures. Dentists use this technology to create a patient-specific printed dental root implant CAD/CAM. Using 3D planning and 3D printing, it is made so shape-specific that it can be placed exactly in the bone of the patient.
Digital Light Processing (DLP)
Another technique often used in dentistry is Digital Light Processing (DLP). This technology also works with photopolymers. However, the lighting principle is different. The object is illuminated from below by a light source. The light is refracted through a prism and sent through a lens to the print tray. By having the light source selectively illuminate the object in different places by the software, the light-sensitive synthetic resin is illuminated in different places. The product to be built then rises over the layer thickness in the container. This is how the next layer is exposed and built up. With DLP technology, a more detailed product can be manufactured with less material loss than usual with SLA technology.
Fused deposition modeling (FDM) or Fused Filament Fabrication (FFF)
Fused deposition modeling (FDM) or Fused Fillament Fabrication (FFF) is a technology that works with a wire. The wire is melted as it builds up the different layers of the material. It is an extrusion technique, in which the software determines how thick the layers become and where the layers of the product to be built are placed. The quality of the printer and the material used determine the quality of the product. This technology is rarely used in dentistry.
One of the oldest printing technologies is Stereolithography (SLA). This system was first described in 1986 by Chuck Hull. He is internationally regarded as the founder of 3D printing. In SLA, a laser passes over a container of liquid resin. By directing the light along a specific path, parts of the resin are cured in places determined by the computer. The build plate then sinks down a distance that determines the thickness of the next layer. Then a thin layer of resin is again rolled out over the build plate. This is also exposed by the laser and cured. The CAD design is built in such a way that the object being printed slowly descends into the container of resin. This technology is used, among other things, to make large models such as skulls. This can be used by the Ophthalmologist as a set-up for surgical procedures. This technology also allows the production of dental models for dentistry in large series.