Researchers at the University of Texas at Dallas have developed technology that could allow dentists to produce permanent 3D-printed zirconia restorations in a single day. Zirconia is considered the go-to material for permanent dental work due to its strength and durability.
With support from the National Science Foundation (NSF), researchers are now working to commercialize the technology for use in crowns, bridges, veneers, and other dental restorations.
“We are excited to advance the commercialization of in-office 3D printed permanent all-ceramic zirconia dental restorations,” said Dr. Majid Minary, professor of mechanical engineering in the Erik Jonsson School of Engineering and Computer Science. “Because crowns can be custom printed for each patient the same day, this approach offers greater customization, faster treatment and the convenience of receiving a permanent restoration in a single visit.”
Why Zirconia Crowns Are Difficult to 3D Print Quickly
Dental crowns are protective caps that are placed over teeth that have been damaged or affected by cavities. Crowns can also be used to support a dental bridge, which replaces a missing tooth.
3D printed dental restorations have become an increasingly attractive option because they can be customized more precisely and tailored to the patient’s tooth color. The manufacturing process can also be more efficient, potentially reducing both costs and material waste. However, currently available 3D printed crowns are generally made from ceramic resins, which do not have the strength of zirconia.
Same-day zirconia crowns are already offered in some dental offices, but they are typically produced by milling rather than 3D printing. Milling requires cutting the restoration from a solid block of zirconia. This approach can restrict the complexity of possible designs and carries the risk of microcracks during milling or sintering.
UT Dallas researchers and their collaborators have addressed one of the biggest obstacles to producing zirconia restorations using 3D printing. Their method dramatically shortens the processing required after a restoration leaves the printer.
The researchers described the technique in the journal. International Ceramics. Before it can be commercially available, the method would still need clinical validation and regulatory approval.
Reduce a process from 20 to 100 hours to minutes
Once a zirconia crown has been 3D printed, it must go through two important stages called debonding and sintering.
During debonding, the crown is slowly heated to remove the resin that holds the zirconia particles together during printing. Traditionally, that step can take between 20 and 100 hours. Once the resin is removed, the crown is sintered. This high-temperature firing process works similar to firing clay in a kiln, causing the zirconium particles to fuse and form a dense, hardened material.
“Disengagement has been the bottleneck in the process,” said Minary, corresponding author of the paper. “It must be done very slowly. If accelerated, the burning polymer turns to gas, and if that gas cannot escape, the crown can crack or fracture. A debonding time of 20 to 100 hours is not practical for same-day dental service. As a result, permanent 3D-printed zirconia restorations are not yet commercially available.”
New technology from UT Dallas reduces the debonding stage to less than 30 minutes, potentially eliminating one of the major barriers to same-day 3D-printed permanent dental restorations.
The system combines enhanced heat transfer with a porous graphite felt that can reach temperatures in excess of 2,550 degrees Fahrenheit. The felt surrounds the 3D printed restoration and gives gases released by the resin a way to escape. At the same time, a vacuum system removes these gases from the environment.
“The combination of all these features is what makes it work,” Minary said. “With our technology, if a doctor wants to offer a 3D-printed zirconia crown in-office, they could provide it to the patient in just a few hours.”
Moving Toward Same Day Commercial Dentistry
The UT Dallas team led by Minary is now working with Pan-AM Dental Laboratory to bring the technology toward commercialization. The collaboration recently received a $550,000 award (grant 2431684) through the NSF Partnerships for Innovation – Technology Translation project.
The commercialization effort also includes 3DCeram Sinto Inc. in Grand Ledge, Michigan; and Dr. Amirali Zandinejad, a prosthodontist in Arlington, Texas, and former associate professor at the Texas A&M University School of Dentistry.
Other UT Dallas-affiliated contributors include Mahdi Mosadegh, first author and doctoral student in mechanical engineering; Moein Khakzad PhD’25; chemistry PhD student Zahra Sepasi; mechanical engineering graduate student Kalyan Nandigama; and Dr. Golden Kumar, associate professor of mechanical engineering.
In addition to the NSF, research for the article was also supported by the US Air Force Office of Scientific Research.