Skip to content. Skip to departments. Skip to most popular. Skip to footer.


Death to Tooth Decay?


By Jennifer St. Germain

Published Apr 1, 2012 8:00 AM

Illustration by Peter Arkle.

Brushing, flossing, white strips and mouthwash: Thanks for all the help, but your services may no longer be required. The end of the cavity could be upon us.

UCLA microbiologist Dr. Wenyuan Shi has developed a mouthwash that completely eliminates the most malevolent of the 1,000 species of bacteria that can live in your mouth—after just one use. In a clinical study, 12 subjects who rinsed just one time with the mouthwash experienced a nearly complete elimination of the baleful bacteria, Streptococcus mutans. Four days after the first rinse, their mouths remained mutans-free.

Shi's mouthwash is currently being tested by the FDA . If the mouthwash passes that hurdle, it will be the first cavity fighter approved since fluoride 60 years ago. But this isn't the first time that Shi, who also is chair of the oral biology section of the UCLA School of Dentistry, has created a tooth decay breakthrough. He also developed a sugar-free orange lollipop that eliminates all of the bad bacteria in a person's mouth.

The days of using regular mouthwash will soon be over, if Shi has anything to do with it. "When you use that, you kill the good and the bad bacteria at the same time," Shi says. "It's like using an herbicide on your lawn—all the weeds come back first. What we created is a weed-specific killer."

Tooth problems are an economic and medical challenge. "Last year in American health spending, heart disease was No. 1, cancer was No. 2 and dentistry was No. 3," Shi notes. "We spent about $100 billion. In part, because it's so old-fashioned. Mechanical removal is still the primary tool."

Ironically, Shi came to dentistry more or less by accident. After growing up in China at the end of the Cultural Revolution, he was among the first group of students sent to America to study. After completing his Ph.D. program in genetics and postdoc in microbiology, the only job available was teaching microbiology to dental students.

"I actually had no dental training," Shi recalls, laughing. But once he began teaching, he was struck by how, in a country where we can reduce the risk of heart attacks and diabetes, battle cancer and lower cholesterol, dentistry remained out of date. The scientist-scholar resolved to work toward converting dentistry from a surgical model to a medical model. The success of the cavity-fighting lollipop (available at, funded by Delta Dental, was just one part of Shi's research empire. Colgate-Palmolive was on board as the sponsor of the mouthwash project.

The dental hero's success surprises him all the time. "Growing up in China, my childhood dream was to become a fortune teller," Shi recalls. "If you would have told me 10 years ago that I'd be doing this, I wouldn't believe it. In the end, I became a scientific fortune teller."

Read more about Dr. Shi's cavity fighting mouthwash here at