Invention measures oral acidity for cavity prediction

US: Researchers from the University of Washington have invented a dental tool that can measure the acidity built-up of bacteria found in dental plaque that leads to cavities.

Still in its prototype phase, the O-pH system is an optical device that measures the reactions of emitted LED light using chemical dye applied to teeth. The system then produces a numerical readout of the acidity (pH level) of the plaque. Information on the acidity of the plaque in turn helps dentists detect the area of the tooth most likely at risk of developing a cavity.

“Plaque has a lot of bacteria that produce acid when they interact with the sugar in our food,” said Manuja Sharma, lead author and a doctoral student in the UW Department of Electrical and Computer Engineering.

“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.”

According to the researcher, the acidity of the oral environment is a key barometer of the threat of future dental problems. Since not all bacteria in the biofilm will lead to cavities, Sharma added, the measuring tool helps to limit the requirement for conducting multiple tests in order to narrow down a plethora of harmful bacteria.

The researchers recruited 30 patients between the ages of 10 and 18 to test their device. The reason for choosing a younger age group is due to the thinner enamel of children, which makes early detection of acid erosion more critical.

One of the limitations that hindered the accuracy of the study, Sharma noted, was the difficulty ensuring the same location on each tooth was consistently measured during each phase of testing. The device is currently undergoing refinements, one of which is to produce images that instantly show the exact location of high acidity.

“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,” Sharma added.

“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!”

The study’s co-authors include: Lauren Lee, UW Department of Microbiology; Matthew Carson, UW Human Photonics Laboratory; David Park, Se An, Micah Bovenkamp, Jess Cayetano, Ian Berude, Zheng Xu, Alireza Sadr, UW School of Dentistry; and Shwetak Patel, UW Electrical and Computer Engineering, Paul. G. Allen School of Computer Science.

This research was funded by the National Science Foundation, Oral Health Monitor, Institute of Translational Health Sciences; and the National Center for Advancing Translational Sciences of the National Institutes of Health.

Source: University of Washington.