Researchers develop O-pH system dental tool for cavity detection

21 Mar 2022 --- Knowledge of dental plaque acidity levels can help dentists and patients determine which areas of a tooth are more vulnerable to cavities. According to the US-based University of Washington, this may now be possible through the O-pH system – a prototype optical device that produces LED light on the FDA-approved chemical dye which coats the teeth. The reactions of the light are measured by the device.

After this process, the O-pH generates a numerical reading of the plaque’s pH, or acidity levels on teeth.

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

“This acid causes the corrosion of the tooth surface and eventually cavities. So, if we can capture information about the acidic activity, we can understand how bacteria grow in the dental biofilm or plaque.”

“We do need more results to show how effective it is for diagnosis, but it can help us understand oral health quantitatively,” adds Sharma.

The study was funded by the National Science Foundation, Oral Health Monitor and the Institute of Translational Health Sciences.

Testing device efficiency
To test the efficiency of the O-pH system dental tool, the researchers recruited 30 individuals between the ages of 10 and 18, with a median age of 15. The researchers chose children for their study because the enamel on children’s teeth is thinner than that on adults’ teeth, making early detection of acid erosion even more critical.

The researchers also enlisted the help of second-and third-year dentistry students, who were supervised by a faculty member, to conduct the measurements with the O-pH equipment.

Eric Seibel, senior author and research professor of mechanical engineering at the University of Washington, noted that adding the acidity test as a new clinical process arose from imagining what happens when a patient sits in the dental chair for the first time before their teeth are cleaned.The dental tool prototype detects where tooth enamel is most vulnerable to plaque acidity.

“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 demineralized,” says Seibel.

Calculating pH before and after sugar rinses
The test was non-invasive as the probe that transmits and gathers light while hovering over the surface of a tooth is attached to the end of a length of cord while the dye is applied to the teeth.

The conditions on the patients’ teeth were read multiple times before and after sugar rinses as well as other condition modifications such as pre-and-post professional dental cleaning.

“The O-pH system 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, ‘Okay, fine, I need to cut down on sugar,’” adds Sharma.

Not all bacteria in the biofilm are harmful or cause cavities, so evaluating the pH of the environment can tell a dentist everything they need to know about the risk of developing problems, explains Sharma.

This reduces the need for testing for specific harmful bacteria, which can be numerous.

Study limitations
One of the study’s limitations, according to the researchers, was the inability to consistently measure the same location on each tooth during each phase of testing.

To solve this shortcoming, the researchers are developing a version of their device that creates images for dentists that highlight the exact location of high acidity, which could lead to the next cavity.

Gum disease testing and policies
To ensure dental health is available for all consumers, Holland & Barrett joined a group of investors to support the development of Floe Oral Care – an online oral health subscription service that uses an at-home saliva testing kit to treat gum disease.

Meanwhile, to gain oral healthcare equality, the National Institutes of Health and the National Institute of Dental and Craniofacial Research established research and policy initiatives, such as dental, medical and behavioral integration policies. These policies will make dental care more affordable and accessible to communities.

Edited by Nicole Kerr