Dentists rely on x-ray imaging and visual inspection to detect caries. However, x-rays can’t detect occlusal early caries. And by the time that dentists can see caries with their naked eye, the decay is fairly advanced.
Researchers at York University of Toronto, though, are using low-cost thermophotonic lock-in imaging (TPLI) to detect developing caries much earlier than x-rays or visual analysis.
TPLI uses a long-wavelength infrared camera to detect the small amount of thermal infrared (IR) radiation emitted from dental caries after stimulation by a light source. It is a noncontact and noninvasive process.
To test the technology, the researchers induced early demineralization of an extracted human molar by submerging it in an acid solution for 2, 4, 6, 8, and 10 days.
The TPLI image taken after just 2 days revealed a lesion, whereas a trained dental practitioner could not visually detect the same lesion even after 10 days of demineralization.
“This paper will have a high impact on the way dentists diagnose incipient caries. The long-wave IR thermophotonic imaging technology is at its nascent steps, but this paper brings it closer to actual clinical practice,” said Andreas Mandelis, professor of mechanical and industrial engineering at the University of Toronto.
The study, “First Step Toward Translation of Thermophotonic Lock-In Imaging to Dentistry As an Early Caries Detection Technology,” was published by the Journal of Biomedical Optics.