Fig. 1. Samples of teeth with different degrees of caries. (a) Healthy teeth; (b) shallow caries; (c) moderate caries; (d) deep caries

Fig. 2. Schematic diagram of fluorescence test system

Fig. 3. Real object diagram of fluorescence spectrum test system

Fig. 4. Comparison of original spectral distribution and spectral distribution after treatment

Fig. 5. Excitation spectra of samples at different fluorescence wavelengths. (a) 480 nm; (b) 623 nm and 685 nm; (c) 625 nm and 685 nm; (d) 623 nm and 690 nm

Fig. 6. Fluorescence spectra of teeth with different degrees of caries. (a) Healthy teeth; (b) shallow caries; (c) moderate caries; (d) deep caries

Fig. 7. Schematic diagram of system structure

Fig. 8. Physical image of fluorescence image acquisition system

Fig. 9. Fluorescence images of teeth with different degrees of caries. (a) Healthy teeth; (b) shallow caries; (c) moderate caries; (d) deep caries

Fig. 10. Fluorescence images of human teeth