Classification of dental diseases using hyperspectral imaging and laser induced fluorescence

•Employing Fluorescence hyperspectral imaging system to discriminate between tooth classes.•Obtaining series of wavelengths, noting each lesion individually.•Tooth lesions have either dark or bright appearance at estimated wavelengths.•New laser wavelength 395-nm was able to identify white spot and root calculus. Early diagnosis of tooth enamel demineralization, and dentin caries lesions, present a valuable solution to avoid or decrease their deleterious effect. The aim of this study was to design a simple, effective, and non-invasive technique, employing a novel laser wavelength to classify and differentiate between various tooth abnormalities in-vitro, by estimating wavelengths, showing distinctive appearance for each tooth class. This study implies a fluorescence hyperspectral imaging system employing a 395-nm laser diode source, irradiating a pre-diagnosed 12 molars and premolars teeth. The obtained reconstructed images were displayed and processed by HSAnalysis2XL, accompanied by a custom made digital, and image signal processing algorithms, revealing the exact wavelengths, characterizing the fluorescence of each tooth pre-diagnosed class. The proposed hyperspectral imaging system was able to discriminate between normal, and abnormal dental classes for the entire specimens. Furthermore, a series of wavelengths, noting each lesion individually were obtained from the spectroscopic hyperspectral output. The root calculus, white spot, dentin caries, and enamel caries have a bright visual appearance at λ3 = 702 nm, λ5 = 771 nm, and λ6 = 798 nm respectively. Consequently, these abnormalities exhibit a dark appearance at λ1 = 421 nm, λ2 = 462 nm, and λ4 = 734 nm. The wavelength selections were confirmed by the grayscale image outcomes. This study provides a set of wavelengths that can be employed by dentists to diagnose white spot, root calculus, and enamel dentin caries lesions under the irradiation of a new UV–vis laser illumination source without, any hazardous thermal or mechanical effects.