Dr. Michael White, a Webster Groves dentist, was listening to his car radio when he heard an interview that gave him something to chew on. A fellow dentist was describing an invention that lets a patient press a button to stop painful drilling.

"When I heard about it, I immediately thought 'this is a good idea,' " he said. "The No. 1 reason why patients leave their dentists is because they hurt them."

In fact, the American Dental Association estimates that 35 million adults have so much anxiety about dental visits that they worry, postpone or avoid seeing their dentist.

So three months ago, Webster Dental Care, where White practices, obtained the device, called The Dental Button, for each of its three chairs.

The button is the brainchild of Dr. Michael Edwards, a dentist from Union who said he got the idea about three years ago. Edwards sketched it and gave it to a business partner to design. The button became available this summer, and Edwards said there are about 100 in use now in the United States and Europe. He said he expects there will be about 1,000 by the end of the year.

The price per button ranges from $900 to $1,500 depending on how many units a dental practice buys, Edwards (left) said.

He said when patients push the button, it shuts off power to the drill. The doctor cannot continue the procedure until the patient gives him the OK, then the doctor resets the system.

"It's just like you took your foot off the gas pedal," he said. "It's no big deal to us (dentists) and it's better than patients trying to get our attention.

"Patients have less anxiety because they have more control, "he said. "People will put up with discomfort for longer if they know they can stop it."

White said his biggest concern was that patients would keep pushing the button and he wouldn't be able to get anything done.

"But I've found I can get things done faster. There are more interruptions when patients raise their hands. With the button they feel safer and they are less likely to interrupt. It's a win for everyone."