Understanding the acoustics of dental drills to reduce patient anxiety

Understanding the acoustics of dental drills to reduce patient anxiety

Fear of the dentist, also known as odontophobia, prevents people from regularly cleaning their teeth and maintaining necessary dental hygiene.

One aspect of fear comes from the sound of the dental drill, which produces a high-pitched whine. As a dentist, Tomomi Yamada has witnessed firsthand the discomfort and fear of her patients.

I originally researched dental materials, but I realized that almost no one – not even dentists – was scientifically addressing this sound problem.”

Tomomi Yamada, assistant professor at Osaka University Graduate School of Dentistry

Yamada, an assistant professor at the Osaka University Graduate School of Dentistry, will present her work on Tuesday, December 2, at 8:20 a.m. HST as part of the sixth joint meeting of the Acoustical Society of America and the Acoustical Society of Japan, December 1-5 in Honolulu, Hawaii.

To understand the drill's aerodynamics, Yamada and her collaborators from Osaka University, 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.

These simulations allowed them to visualize how air moves through and around the drill and creates the noise.

“Our research shows that simply making the drill quieter is not enough to make the noise less unpleasant,” Yamada said. “What really matters is improving the sound quality.”

Researchers also tested the psychological effects of the dental drill, which can produce high-pitched sounds of nearly 20 kilohertz, on children and adults. They found that younger listeners responded differently to the exercise, finding the sounds louder and more unpleasant.

"This suggests that children's fear of tooth noise is not only psychological but also physiological in nature," Yamada said. “Children really hear these sounds differently, so their fear of dental treatment is a real sensory response and not just their imagination.”

To address this problem, Yamada and her colleagues are working on optimizing the drill's blade geometry and exhaust port to minimize noise while maintaining performance.

In order to get the dental industry to adopt this new technology, it is crucial to find a balance between device performance and safety, as a quieter drill will not necessarily get the job done.

“In the future, we hope to work with dental manufacturers through industry-academic partnerships and advance commercialization after completing the necessary regulatory and durability testing,” Yamada said.

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