The Future of 3D Printing in Practice
Chris Brown, BSE
Three-dimensional printers and drones seem to be in the news nearly every day. We won’t see many drones chairside (thankfully), but progress is being made that could someday put 3D printers in dental offices.
Milling machines have been around for years in dental offices or laboratories. They are considered subtractive manufacturing devices—start with a block or disk and remove the material that isn’t needed to leave what is needed. Three-dimensional printers are considered additive manufacturing devices—start with an empty platform or tray and build an object layer by layer. The method of building varies from curing a photosensitive resin with a laser, projector, or lamp (SLA, DLP, or jetted-resin) to melting a thin strand plastic material (FDM) or using a laser to melt or sinter powdered metal (SLS/SLM).
Dental laboratories have embraced a variety of 3D-printed products into their workflows. It started with resin-based printed models from digital impressions and resin patterns for casting metals or pressing ceramics. In recent years, materials, software, and workflow processes have been improved to make casting printed partial denture frameworks a viable operation. Although widely adopted in Europe for some time, several production centers in the United States have now added and focused on SLS/SLM printers to produce partial frameworks and non- or semi-precious substructures. Other 3D-printed laboratory-based products include digitally designed and planned surgical guides, orthodontic aligner trays, and removable denture try-ins.
Dental offices have not implemented 3D printers as widely as laboratories. Those offices with their own internal laboratories are the obvious early adopters, as are those with enough volume to justify a 3D printer for orthodontic aligners, or a CBCT and the desire to print surgical guides. Outside of those niche markets, 3D printers in the dental office remain more of a future opportunity than an immediate one.
Production time, available materials, and post-processing remain the limiting factors for printers in a dental office. There is a very real restriction when it comes to printed layer thickness, height of the final product, and printing speed. The sharper or smaller the vertical resolution is for the printed part, the more layers that need to be printed and the longer it takes to print. Of course, the taller the part, the longer it takes to print. Many current printing technologies used in the dental space are operating at 12 mm to 14 mm of vertical build per hour. Progress is being made to speed up the printing process, but it is a significant challenge given the resolutions necessary for most dental appliances or products.
Today’s current printing technologies all require some form of post-processing after printing. This ranges from cleaning with a high-pressure water spray to soaking in an alcohol solution and secondary curing to physical cutting and sandblasting. None of the processes are terribly complicated, but they do add to the overall time to completion of a print job.
Currently, there are only a few printable materials that are cleared by the FDA for use in the mouth. The most common are materials for short-term temporary contact such as surgical guides. Recently, clearance was granted for a provisional crown and bridge material. Development and testing are no doubt underway for long-term materials that could be used for bite splints, dentures, and other appliances or products. The challenge is matching desirable material properties with a printable technology that is also biocompatible.
Reducing print times and post-processing tasks in addition to developing optimal materials is not an easy task. However, the market opportunity is very lucrative for printer and material manufacturers alike.
About the Author
Chris Brown, BSE
Manager
Aclivi, LLC
CAD/CAM Consultant
The Dental Advisor
Ann Arbor, Michigan
