Abstract
The detection of early stages of caries is still one of the major challenges in preservative dentistry. Since it is known from polarized light microscopy (PLM) that intrinsic enamel birefringence is affected by demineralization, polarization-sensitive optical coherence tomography (PSOCT) could facilitate the noninvasive detection and assessment of early carious lesions. The present study aims to correlate enamel lesion progression and depolarization measurements based on PSOCT in an artificial demineralization model. A total of 18 enamel slabs were prepared from bovine incisor teeth and demineralized in an acetic buffer solution for up to 49 days. The degree of polarization (DOP)—indicating depolarization and thus, demineralization—was calculated from PSOCT measurements and compared to lesion depth which was measured from PLM images. Artificial lesions showed characteristic zones of natural enamel demineralization in PLM images. DOP representations showed no depolarization for sound, nondemineralized enamel, whereas significant changes were found after 15 days of acid-exposition. The linear regression analysis of the DOP and the measured lesion depth showed a substantial correlation ( R 2 = 0.71 ). The results indicate that PSOCT-based depolarization imaging provides an unambiguous contrast for initial enamel demineralization which is correlated to the lesion progression.
Highlights
The interpretation of polarization changes at dental hard tissue with polarized light microscopy (PLM) represents a milestone in caries research that has provided significant contributions to the understanding of the histopathological nature of the caries process [1]
The results indicate that Polarization-sensitive optical coherence tomography (PSOCT)-based depolarization imaging provides an unambiguous contrast for initial enamel demineralization which is correlated to the lesion progression
PSOCT-based representations of depolarization were presented for imaging enamel demineralization induced by an artificial lesion model and compared with PLM images of corresponding thin sections
Summary
The interpretation of polarization changes at dental hard tissue with polarized light microscopy (PLM) represents a milestone in caries research that has provided significant contributions to the understanding of the histopathological nature of the caries process [1]. In 1958, it was shown that demineralization of enamel is accompanied by distinct changes of polarization properties [2]. Polarization-sensitive optical coherence tomography (PSOCT) obtains depth-resolved images of polarization properties noninvasively with high resolution (typically 5–20 μm) and, as it is based on near-infrared light, without the hazards of ionizing radiation. In 2000, Baumgartner et al presented the first PSOCT measurements of dental structures [3] and characterized the birefringence of the enamel, which is due to the anisotropy of hydroxyapatite crystals, organized in rodlike structures.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
