Optical Probe Measures Dental Plaque Acidity

A team at the University of Washington have developed an optical probe that can detect the acidity of dental plaque. The acidity created by bacteria within plaque causes cavities, and knowing which areas of the teeth are particularly acidic could help dentists to predict where cavities are likely to arise. The knowledge could help someone change their oral hygiene practices, such as brushing more in high-risk areas. Moreover, the new device provides a quantitative measurement of overall oral health, which may give dentists and other clinicians an easy way to diagnose and track certain conditions.

Children learn at a young age that plaque on their teeth can cause cavities, also known as caries, and parents highlight the importance of regular brushing to remove that plaque. But plaque, which is essentially a bacterial biofilm, is not the full story, and all plaques are not created equal. The specific bacteria present in the plaque are predictive of how likely it is to cause a cavity, since the acid released by certain bacteria within these biofilms is responsible for the acid erosion that commonly causes cavities.

“Plaque has a lot of bacteria that produce acid when they interact with the sugar in our food,” said Manuja Sharma, a researcher involved in the study. “This acid is what causes the corrosion of the tooth surface and eventually cavities. So, if we can capture information about the acidic activity, we can get an idea of how bacteria are growing in the dental biofilm, or plaque.”

The new technology, which the researchers have called the O-pH system, relies on fluorescence to measure local acidity levels in and around the teeth. To begin with, a dentist would apply a tasteless, FDA-approved dye to the mouth before a patient has had their teeth cleaned. Eric Seibel, another researcher involved in the study, said that “a dentist would rinse them with the tasteless fluorescent dye solution and then get their teeth optically scanned to look for high acid production areas where the enamel is getting demineralized.”

The current iteration of the device is a prototype, and the researchers are still figuring out how it can be most useful to patients and dentists alike. One aspect involves education, where a dentist can show a patient in real-time which areas of their mouth are at high-risk, or if they are at an overall high-risk because of poor oral hygiene or a sugary diet.

“We do need more results to show how effective it is for diagnosis, but it can definitely help us understand some of your oral health quantitatively,” said Sharma. “It can also help educate patients about the effects of sugar on the chemistry of plaque. We can show them, live, what happens, and that is an experience they’ll remember and say, OK, fine, I need to cut down on sugar!”

Study in IEEE Transactions on Biomedical Engineering: O-pH: Optical pH Monitor to Measure Oral Biofilm Acidity and Assist in Enamel Health Monitoring

Via: University of Washington