Technology offers new perspectives on patients’ smiles
Story by Gail Allyn Short • Photo by Steve Wood
Digital technology is added new dimensions in oral care. Just ask Daniel Givan, DMD, Ph.D., professor of restorative sciences at the School of Dentistry. “We’ve had more changes in dental technology in the last five years than in the previous 100 years,” he says. And these innovations help dentists, orthodontists, oral surgeons and others tailor care and treatment to fit each patient’s unique needs. Here are five ways 3D shapes the smile:
Best impressions: Anyone who has had braces, crowns and bridges can remember the wet, sticky, messy ordeal of holding plaster in their mouth for several minutes to make impressions. Now intraoral or optical impression scanners can capture digital images of a patient’s teeth using light projected from hand ridges. “The device takes multiple pictures, which are combined to create a virtual 3D model,” explains Shirin Khoynezhad, DDS, DMSc., assistant professor of prosthetics. Dental professionals can manipulate the virtual model to visualize the teeth and develop plans for their restoration. They then send the electronic impression to a laboratory that manufactures items such as crowns, bridges, inlays or mouth guards. The technology solves another problem with conventional imprints. Because plaster can change in size as it sets, dentists often had to adjust finished crowns and bridges to make them fit properly, Khoynezhad says.
Quick fixes: Patients used to wait weeks to have crowns and other prostheses made or repaired. Now computer-aided design (CAD) and computer-aided manufacturing (CAM) make it possible for patients to receive their custom prosthetics in days—sometimes hours. Dentists take digital scans of a patient’s teeth and upload them to a lab, where a CAD machine creates the unique dental appliance. Then, using a CAM mill, a technician creates the final prosthesis from materials such as ceramics and resin composites.
Printed prosthesis: Some custom prostheses are now produced on 3D printers, which use resins to form the necessary part layer by layer. “3-D printing has exploded,” says Givan. “Now we produce temporary crowns and bridges. Some are more experimental right now, but this technology is here to stay.”
3D scans (top) guided jaw reconstruction for Valerie Accetta, helping her teach and sing again.
Jaw Settings: A misaligned jaw affects the ability to chew or speak, as it can be painful. Digital jaw tracking systems use sensors to observe, record and measure the movements of the jaw, up-down and side-to-side, relative to the rest of the skull. When Valerie Accetta, MFA, head of musical theater at UAB, needed reconstructive surgery to repair wear and tear in her jaw, the team that successfully treated her used jaw tracking technology as part of their surgical preparations, says Chung H Kau, DDS, Ph.D. D., Department of Orthodontics. “Jaw tracking was critical to our success as it allowed us to study the relationship of Valerie’s jaw and muscles in motion in real time,” says Kau. “From there, we were able to digitally design exactly where the custom joints would fit in her jaw, a process that helps everyone involved be as precise as possible before surgery begins.”
Surgery preparation: Kau and Patrick Louis, DDS, MD, professor of oral and maxillofacial surgery, collaborated on Accetta’s case using virtual surgical planning software. The technology allowed them to transfer and review 3D images of Acceta’s jaw together and strategize, simulate the position of the jaw and develop the best preoperative plan — all online. Today Acceta sings and teaches again.
Look to 3D innovations to bring smiles to more dentists—and give dentists greater precision and efficiency—Givan says. “Technology is a help,” he says, “but it still requires well-trained people to ask the right questions and understand how to appropriately apply these tools to each patient.”
