Tuft’s proof-of-concept demonstration study shows how changes in saliva can be employed as biomarkers for development of future diagnostic monitoring devices and applications

For years, pathologists and dentists have recognized that the mouth contains many useful biomarkers for a wide range of health conditions and diseases. Now a study by a research team at Tufts University School of Engineering (Tufts) has demonstrated that a tooth-mounted sensor can reliably measure certain target markers.

In this proof-of-concept study, Tufts researchers developed a tooth-mounted sensor that monitors food consumption as it enters the body. This potentially adds behavioral data to the growing list of exploitable biomarkers available to developers of in vitro diagnostics (IVDs) and wearable medical monitoring devices. For that reason, many clinical laboratory managers and anatomic pathologists will want to track further development of this technology, which uses the mouth as the source of the markers to be measured.

A report detailing the device was first published in the scientific journal Advanced Materials in March of this year.

Sensor Reacts to Biomarkers in Saliva

The 2×2-millimeter flexible sensor consists of three layers and adheres to the tooth like a sticker. It has two gold outer rings surrounding an inner layer of bio-responsive material that is highly sensitive to glucose, salt, and alcohol. The presence of any of these substances alters the electrical properties of the sensor and incites it to transmit radio frequency waves that can be received by mobile devices.

Researchers conducting a proof-of-concept study at Tufts University School of Engineering have developed “a materials‐based strategy to add utility to traditional dielectric sensors by developing a conformal radiofrequency (RF) construct composed of an active layer encapsulated between two reverse‐facing split ring resonators,” their paper published in Advanced Materials notes. The sensor is shown above mounted to a tooth, where it reacts to the presence of certain biomarkers in the saliva, triggering the transmission of an RFID signal. This device has the potential to also measure the same biomarkers used in clinical laboratory tests. (Photo copyright: Smithsonian Magazine/Tufts University School of Engineering.)

There are many possible uses for this tooth-mounted sensor. Individuals with medical conditions such as diabetes, celiac disease, or hypertension, which require them to avoid certain substances in their diet, could benefit from utilizing a device that employs the technology under development at Tufts.

Such a gadget might also help those trying to lose weight. The creators hope to enhance the material, so it has the ability to discern additional nutrients and chemicals.

“If you can evolve the sensor and engineer it to have a database of food consumption, then you could think about nutrition management,” Fiorenzo Omenetto, PhD, Professor, Department of Biomedical Engineering at Tufts and one of the authors of the research told Smithsonian Magazine. “That could be reminding us that we’re indulging too much in sugar or something like that.”

It also could potentially detect physiological or chemical changes taking place in the body by detecting certain bio-markers in the saliva.

“In theory we can modify the bio-responsive layer in these sensors to target other chemicals. We’re really limited only by our creativity,” Omenetto noted in a news release. “We have extended common RFID [radio frequency identification] technology to a sensor package that can dynamically read and transmit information on its environment, whether it is affixed to a tooth, to skin, or any other surface.”

Other Food Intake Devices

There have been previous attempts to develop wearable devices that monitors food intake. However, those gadgets usually required the use of mouth guards and head gear, which are too cumbersome for continuous everyday use. The minute size of the Tufts tooth-mounted device renders it more practical for consumers. And, since it can be mounted anywhere on a tooth—front or back—it can be made undetectable while being worn.

“This study is an interesting proof-of-concept demonstration that small, wireless biosensors can detect changes in saliva due to the presence of compounds such as salt, sugar, and alcohol,” Ben Almquist, PhD, a lecturer in the Department of Bioengineering at Imperial College London, told Smithsonian Magazine.

“For instance, for continuous monitoring of food intake, the sensors will need to be robust enough to withstand abrasion during chewing,” Almquist noted. “In addition, foods are complex mixtures of compounds including salts, sugars and proteins, and the relative amounts of each that enter into saliva will depend on factors such as the nature of the food [i.e., cooked versus fresh], the amount of chewing, and the time in the mouth before swallowing.”

The device currently remains in the prototype stage and more testing will be needed to determine its efficacy and durability. However, the emergence of such wearable devices for medical use suggests valuable opportunities for clinical laboratories.

Because data captured from the tooth-mounted device is transmitted wirelessly, clinical laboratories could potentially store and monitor the data, compare the collected data to other medical laboratory test results for the same patient, then communicate that information to clinicians, other caregivers, and even the patients. This would be a new way for clinical laboratories to provide innovative, value-added services to healthcare professionals and consumers.

—JP Schlingman

Related Information:

This Tiny Tooth Sensor Could Keep Track of the Food You Eat

Scientists Develop Tiny Tooth-mounted Sensors That Can Track What You Eat

A New Tooth-mounted Sensor Will Soon Help You Lose Weight

Functional, RF‐Trilayer Sensors for Tooth‐Mounted, Wireless Monitoring of the Oral Cavity and Food Consumption