New Technique Could Cut a 100-Hour Dental Crown Process to Under 30 Minutes

Researchers at the University of Texas at Dallas have developed a technology that could let dentists produce permanent 3D-printed zirconia dental restorations, such as crowns, bridges and veneers, in a single day. Zirconia is considered the gold-standard material for permanent dental work because of its strength and durability, but same-day zirconia crowns available today are typically produced by milling a solid block, which limits design complexity and risks micro-cracking.

3D-printed crowns are attractive because they can be customized more precisely and matched to a patient's tooth color, but crowns printed from zirconia must pass through two steps after printing: debinding, which slowly heats the crown to remove the resin holding zirconia particles together, and sintering, a high-temperature firing that fuses the particles into a dense material. Debinding has traditionally required 20 to 100 hours, because heating it too quickly can cause trapped gas to crack or fracture the crown, making the process impractical for same-day dental service.

"Debinding has been the bottleneck in the process," said Dr. Majid Minary, professor of mechanical engineering at UT Dallas and corresponding author of the study, published in the journal Ceramics International. The new technology, which combines improved heat transfer with a porous graphite felt that can reach temperatures above 2,550 degrees Fahrenheit (1,400 degrees Celsius) surrounding the restoration, gives escaping gases a path out while a vacuum system removes them from the surrounding area. This combination cuts debinding to less than 30 minutes.

With National Science Foundation (NSF) support, including a $550,000 award through the NSF's Partnerships for Innovation Technology Translation project, the researchers are now working with Pan-AM Dental Laboratory to commercialize the technology. "With our technology, if a practitioner wants to offer a 3D-printed zirconia crown chair-side, they could provide it to a patient within just a few hours," Minary said. The method would still need clinical validation and regulatory approval before becoming commercially available.