HONOLULU, Dec. 2, 2025 — Dental anxiety, also known as odontophobia, prevents people from getting their regular cleanings and keeping up with necessary dental hygiene.
One aspect of the anxiety comes from the sound of the dental drill, which makes a high-pitched whining sound. As a dentist, Tomomi Yamada has witnessed discomfort and fear in her patients firsthand.
"Originally, I was doing research on dental materials, but I realized that almost no one — not even dentists — was tackling this sound problem scientifically," Yamada said.
Yamada, an assistant professor at the University of Osaka's graduate school of dentistry, will present her work Tuesday, Dec. 2, at 8:20 a.m. HST as part of the Sixth Joint Meeting of the Acoustical Society of America and Acoustical Society of Japan, running Dec. 1-5 in Honolulu, Hawaii.
To understand the aerodynamics of the drill, Yamada and her collaborators from the University of Osaka, Kobe University, and National Cheng Kung University used Japan's flagship supercomputer to conduct large-scale aeroacoustics simulations. They analyzed the internal and external airflow of the dental drill, which is powered by compressed air and rotates at about 320,000 revolutions per minute.
From these simulations, they were able to visualize how air moves through and around the drill to create the noise.
"Our research showed that just making the drill quieter isn't enough to make the sound less unpleasant," Yamada said. "What really matters is improving its sound quality."
The researchers also tested the psychological effects of the dental drill, which can generate high-pitched sounds reaching nearly 20 kilohertz, with children and adults. They found that younger listeners had different reactions to the drill, perceiving the sounds as louder and more unpleasant.
"This indicates that children's fear of dental sounds is not merely psychological but also physiological in nature," said Yamada. "Children truly hear these sounds differently, so their fear of dental treatment is a genuine sensory response, not just imagination."
To address this, Yamada and her colleagues are working on optimizing the blade geometry and exhaust port of the drill to minimize the noise while maintaining the performance.
To get the dental industry to adopt this new technology, achieving a balance between the device's performance and safety is key, since a quieter drill won't necessarily get the job done.
"Moving forward, we hope to work with dental manufacturers through industry–academia partnerships, progressing toward commercialization after completing the necessary regulatory and durability testing," Yamada said.
