A new dental imaging technology can image and quantify artificial occlusal caries by measuring the increase in backscattering and depolarization of near-infrared light, according to a study published in the February issue of the journal Caries Research.
Using an artificial caries model, researchers at the School of Dentistry, University of California, San Francisco, investigated the relationship between the magnitude of backscattered light and depolarization recorded by polarization-sensitive optical coherence tomography (PS-OCT) with changes in the enamel mineral volume.
PS-OCT is an imaging technique that records spatially resolved changes in polarized light backscatter from the tooth enamel.
Researchers created artificial lesions on a selected region of the occlusal surfaces of 10 sound posterior teeth using a 14-day pH cycling model. They used an all-fiber-based PS-OCT system operating at 1,310 nanometers to collect serial images at day zero and at day 14 before sectioning the tooth. They then obtained quantitative mineral content profiles and relative mineral losses from transverse sections of the carious enamel samples using high-resolution digital microradiography (DM).
They used line profiles of PS-OCT and DM images to evaluate severity and depth of the artificial caries. They found a strong correlation between the lesion depths calculated using both imaging modalities. The researchers also found that PS-OCT had a couple of advantages over conventional OCT. These advantages included increased contrast to help differentiate between areas of normal and demineralized enamel and the technology’s provision of a straightforward approach to quantifying carious lesions, which is more insensitive to the varied surface topography of the tooth.
This study was supported by a grant from the National Institute of Dental and Craniofacial Research, National Institutes of Health.
