3D Printing Part 1

By: Dr. Kyle King

When I graduated from dental school in 2015, 3D printing was often talked about as the future of dentistry; however, I had never seen one in action until a CE course a year later. Now, fast forward five years post-graduation, and I cannot envision practicing without one.

3D printing has numerous uses and I feel that we are just scratching the surface with the capabilities it can provide. Whether it be 3D printing surgical guides for implant placement, a surgical template for full facial reconstructive surgeries, orthodontic models, bruxism splints, or just diagnostic models, the indications in dentistry are enormous.

Many people have heard of 3D printing but are unaware of exactly how it works. The easiest way I can describe it, is it is like milling a crown from a block, but backwards (if that makes sense). Whenever you mill a crown from a puck or block, it is a subtractive process. The burs whittle the block away until you’re left with the structure intended.  When 3D printing an object, it is the opposite, and therefore an additive process. The 3D printer we utilize in our office is the Moonray S, an SLA printer, which basically has a pool of liquid resin (think flowable composite), that has a laser (curing light), and shoots the laser through the liquid resin, hardening it precisely in micron layers. 

There are two main types of 3D printing used in dentistry; SLA and DLP based printers.  SLA stands for stereolithography, and DLP stands for Digital Light Projection.  As aforementioned, SLA printing uses a liquid resin tank, and uses a laser to cure each point of the desired object in layers. DLP is similar in that it uses liquid resin, and a transparent liquid resin tank, but when printing it uses a digital projection screen and flashes an image layer across the entire build platform, curing all of the points at the same time.  

Both SLA and DLP printing are highly accurate 3D printers and can produce models at 20micron resolution to 100 micron resolution. However, there is another type of 3D printing, called filament based 3D printing, and those printers are commonly found in high schools, colleges, or at home hobbyist printers. Filament based printers use a spool of filament resin, and it is incrementally layered as well. However, this printing is the least accurate in resolution, and the strength of the models and structures printed using this method is often extremely weak.  

As mentioned, 3D printing has numerous indications in dentistry. While I know many are familiar with the term 3D printing, I hope this clarifies how it works a little bit better. Part II will include clinical applications for 3D printing.  

Images courtesy of FormLabs.com