Detection and analysis of enamel cracks by ICG-NIR fluorescence dental imaging

Authors

Zhongqiang Li, Division of Electrical and Computer Engineering, College of Engineering, Louisiana State University, Baton Rouge, Louisiana.
Yoshita V. Holamoge, Division of Electrical and Computer Engineering, College of Engineering, Louisiana State University, Baton Rouge, Louisiana.
Zheng Li, Division of Electrical and Computer Engineering, College of Engineering, Louisiana State University, Baton Rouge, Louisiana.
Waleed Zaid, Oral and Maxillofacial Surgery, School of Dentistry, Louisiana State University Health Science Center, Baton Rouge, Louisiana.
Michelle L. Osborn, Department of Comparative Biomedical Science, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana.
Alexandra Ramos, Department of Comparative Biomedical Science, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana.
Jacob T. Miller, Division of Electrical and Computer Engineering, College of Engineering, Louisiana State University, Baton Rouge, Louisiana.
Yanping Li, School of Environment and Sustainability, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
Shaomian Yao, Department of Comparative Biomedical Science, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana.
Jian Xu, Division of Electrical and Computer Engineering, College of Engineering, Louisiana State University, Baton Rouge, Louisiana.

Document Type

Article

Publication Date

9-1-2020

Abstract

Cracked teeth are the third most common cause of tooth loss, but there is no reliable imaging tool for the diagnosis of cracks. Here, we demonstrate the feasibility of indocyanine green near-infrared fluorescence (ICG-NIRF) dental imaging for the detection of enamel cracks and enamel-dentin cracks in vitro in the first (ICG-NIRF-I, 700-950 nm) and second (ICG-NIRF-II, 950-1700 nm) imaging windows with transmission excitation light, and compared ICG-NIRF with conventional NIR illumination-II (NIRi-II) and X-ray imaging. Dentin cracks were detected by CT scan, while most enamel cracks, undetectable under X-ray imaging, were clearly visible in NIR images. We found that ICG-NIRF-II detected cracks more effectively than NIRi-II, and that light orientation is an important factor for crack detection: an angled exposure obtained better image contrast of cracks than parallel exposure, as it created a shadow under the crack. Crack depth could be evaluated from the crack shadow in ICG-NIRF and NIRi-II images; from this shadow we could determine crack depth and discriminate enamel-dentin cracks from craze lines. Cracks could be observed clearly from ICG-NIRF images with 1-min ICG tooth immersion, although longer ICG immersion produced images with greater contrast. Overall, our data show that ICG-NIRF dental imaging is a useful tool for diagnosing cracked teeth at an early stage.

Publication Source (Journal or Book title)

Annals of the New York Academy of Sciences

First Page

52

Last Page

63

Recommended Citation

Li, Z., Holamoge, Y. V., Li, Z., Zaid, W., Osborn, M. L., Ramos, A., Miller, J. T., Li, Y., Yao, S., & Xu, J. (2020). Detection and analysis of enamel cracks by ICG-NIR fluorescence dental imaging. Annals of the New York Academy of Sciences, 1475 (1), 52-63. https://doi.org/10.1111/nyas.14374