Scientists Are Trying to Fix the Worst Sound in the World: the Dentist’s Drill

If you’re nervous about going to the dentist, you’re not alone. In fact, dental anxiety has an official name, odontophobia, and it’s a real problem, because it keeps people from maintaining their dental hygiene. One dentist is on a mission to ease people’s odontophobia by addressing one of the triggers—the terrible sound of dental drills.

Tomomi Yamada, a dentist at the University of Osaka’s graduate school of dentistry, and colleagues have investigated the aerodynamics of dental drills and how people of different ages perceive their high-pitched whining sound. The aim is to design a drill that lessens the noise while maintaining performance.

The sound problem

“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 in a statement from the Acoustical Society of America. She presented their research yesterday during the Sixth Joint Meeting of the Acoustical Society of America and the Acoustical Society of Japan in Honolulu, Hawaii.

The team used a supercomputer to run large-scale aeroacoustics simulations. Aeroacoustics is the study of sound created by airflow and its influence. The simulations allowed the researchers to visualize and study the air movement through and around the drill to create noise—powered by compressed air and rotating at around 320,000 revolutions per minute.

“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.â€

Children have it worse

Yamada and her colleagues also investigated the psychological effect of the dental drill’s sound with children and adults (imagine volunteering to listen to dental drills more than you already have to!). The drill’s nightmarish sounds can reach almost 20 kilohertz, and they revealed that younger individuals felt the sound to be louder and more unpleasant than adults.

“This indicates that children’s fear of dental sounds is not merely psychological but also physiological in nature,†Yamada explained. “Children truly hear these sounds differently, so their fear of dental treatment is a genuine sensory response, not just imagination.†In other words, your children are justified in pretending to be sick on the day of their dentist’s visit.

Within this context, the team is trying to improve the blade geometry and exhaust port of the drill to lessen the noise while safeguarding performance. They’ll have to strike the right balance between performance and safety to get the dental industry on board, because a drill that is simply quieter isn’t necessarily an effective one.

“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.

Here’s to hopefully not having to wear earphones blasting rock music to the dentist anymore!