Modified Smartphone Camera Can Detect Dental Plaque Biofilm
Selfies take on new meaning in oral healthcare with the advent of this technology.
Researchers at the University of Washington in Seattle have devised a way to use smartphone cameras to detect microbes both on the skin and in the oral cavity. This innovation will enable the identification of everything from acne-causing bacteria to the pathogens that cause gingivitis and plaque biofilm. But some tinkering was required.1
Lead researcher Ruikang Wang, MSc, PhD, a University of Washington professor of bioengineering and ophthalmology, explains that conventional smartphone cameras capture images in RGB, or a visual spectrum of red, green, and blue. This makes it difficult if not impossible to capture images of bacteria, which emit colors beyond the RGB spectrum, within which they are invisible.
Work Around
To solve this problem, the researchers added a three-dimensional-printed ring with 10 inexpensive LED black lights to a smartphone case. The LED lights are key in that they excite porphyrins, a class of bacteria-derived molecules that can be found accumulating on the skin surface and in the mouth where bacteria are present in high amounts.
Exposure to the LED lights triggers them to emit a red fluorescent signal that the smartphone camera can pick up. Other components such as proteins and fatty acids will instead fluoresce in colors such as blue or green.
Conversion
The LED illumination rendered enough visual information for the team to computationally convert the RGB image colors into other wavelengths, resulting in pseudo-multispectral images with 15 wavebands—as opposed to just three in the original images. In processing the images, they were able to differentiate the bacteria signals from the background signals and more clearly distinguish porphyrin clusters.
In fact, detection of additional bacterial signatures that illuminate under LED light could be possible with further modifications. The researchers contend that in contrast to traditional bacteria assessment techniques, such a method can provide real-time visualization, molecular identification, and mapping. And because it works in snapshot mode, complications due to motion artifacts are reduced.
According to Wang, the beauty of this technique is that it provides the ability to visualize different components simultaneously. “If you have bacteria producing a different byproduct that you want to detect, you can use the same image to look for it—something you can’t do today with conventional imaging systems,” he notes.2 The result is a quick, relatively low-cost way for users to track the presence of harmful bacteria at home.
Translation
Smart phones have become ubiquitous in today’s society, even in rural areas. Because of this, for areas with limited access to professional dental care, the use of such modified smartphones could be a boon to oral health maintenance.
Alerted to plaque development through color differentiation, users would have a fighting chance to avert dental diseases before they become a serious issue—whether that means addressing the problem through use of floss, interdental brushes, or toothbrushing, or scheduling a visit with an oral health professional. During dental visits, plaque identification would be streamlined.
Wang says that there are multiple directions in which the research can go. Plans are in the works to develop ways of calibrating different cameras to their imaging platform, build mobile apps, and apply cloud computing, allowing real-time and online processing for both mobile and remote visits.
