Fluorescence spectrometry based chromaticity mapping, characterization, and quantitative assessment of dental caries

Cheng Wang; Rongjun Zhang; Yongfu Jiang; Jiayang Li; Nizhou Liu; Le Wang; Peiyu Wu; Junbo He; Qi Yao; Xiaoling Wei

doi:10.1016/j.pdpdt.2021.102711

Fluorescence spectrometry based chromaticity mapping, characterization, and quantitative assessment of dental caries

Photodiagnosis Photodyn Ther. 2022 Mar:37:102711. doi: 10.1016/j.pdpdt.2021.102711. Epub 2022 Jan 2.

Authors

Cheng Wang¹, Rongjun Zhang², Yongfu Jiang³, Jiayang Li³, Nizhou Liu³, Le Wang², Peiyu Wu⁴, Junbo He², Qi Yao⁵, Xiaoling Wei⁶

Affiliations

¹ Department of Optical Science and Engineering, School of Information Science and Technology, Academy for Engineering and Technology, Shanghai Stomatological Hospital, Fudan University, Shanghai, China; State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun, China.
² Department of Optical Science and Engineering, School of Information Science and Technology, Academy for Engineering and Technology, Shanghai Stomatological Hospital, Fudan University, Shanghai, China.
³ Department of Optical Science and Engineering, School of Information Science and Technology, Academy for Engineering and Technology, Shanghai Stomatological Hospital, Fudan University, Shanghai, China; Shanghai Key Laboratory of Craniomaxillofacial Development and Diseases, Fudan University, Shanghai, China.
⁴ College of Architecture and Urban Planning, Shenzhen University, Guangdong, China.
⁵ Department of Optical Science and Engineering, School of Information Science and Technology, Academy for Engineering and Technology, Shanghai Stomatological Hospital, Fudan University, Shanghai, China; State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun, China. Electronic address: yaoqi@fudan.edu.cn.
⁶ Department of Optical Science and Engineering, School of Information Science and Technology, Academy for Engineering and Technology, Shanghai Stomatological Hospital, Fudan University, Shanghai, China; Shanghai Key Laboratory of Craniomaxillofacial Development and Diseases, Fudan University, Shanghai, China. Electronic address: xiaoling_wei@fudan.edu.cn.

PMID: 34986426
DOI: 10.1016/j.pdpdt.2021.102711

Abstract

Purpose: Dental caries detection, especially the accurate detection of early caries, facilitates prompt interventions. It is reasonably common to use fluorescence imaging for classification and evaluation of caries, but lacks a quantitative, precise and easy-to-use characterization for practical applications. In this study a quantitative approach for caries stage detection by correlating caries spectral and chromatic features was examined.

Methods: A 405 nm LED light source was used as the excitation source. A hyperspectral imaging camera is employed to collect 336 spectral data of different caries stages. Four critical intervals for different stages of caries were extracted by fluorescence spectral features. The mapping relationship between caries spectral and chromatic features was established by Fast Formula Fitting (FFF) and Neural Network Fitting (NNF) methods.

Results: The 470-780 nm spectral power distribution was proved to be the best matching color waveband guiding the selection of filters in future instrument development. The correlation coefficients for the two fitting methods were 0.990 and 0.999, respectively. Both methods achieved caries stage prediction at the pixel level with high accuracy using color information. The visualization region in the chromaticity diagram was created.

Conclusions: This quantitative method enables accurate prediction of caries on the entire tooth surface and facilitates the development of portable and low-cost caries detection instruments.

Keywords: Chromaticity coordinates; Dental caries; Fluorescence spectroscopy; Hyperspectral imaging; Neural network fitting, Spectral area ratio.

MeSH terms

Dental Caries* / diagnostic imaging
Fluorescence
Humans
Optical Imaging
Photochemotherapy* / methods
Spectrometry, Fluorescence