A simultaneous analysis of microregions of carious dentin by the methods of laser-induced fluorescence and Raman spectromicroscopy

Using laser-induced fluorescence and Raman spectromicroscopy methods, an analysis of microregions of the human tooth dentin tissue affected by caries was performed within the frameworks of the integrated research technique ($\lambda$ = 514.5 nm). A simultaneous screening by two methods of microregions close to the interface between the intact and infected dentin allowed us to observe an intensive response in both the Raman spectrum and range of induced fluorescence. The data analysis showed that vibrational modes registered by the method of the Raman spectromicroscopy are related to the amino acids of DNA/RNA of cariogenic bacteria and porphyrins, which are a consequence of their vital activity. This is confirmed by the data of laser-induced fluorescence. The revealed spectral features can be successfully used in stomatology when diagnosing carious lesions of different level of formation.