Use of Raman spectroscopy for diagnosis of disease in dental tissue

Abstract

Raman spectra of samples of tooth enamel, dentin, and cement were obtained using an experimental unit for noninvasive study of tooth surfaces, carious cavities, and dental pulp calcifications. This spectral analysis enabled us to study the distribution of mineral and organic components in solid tooth tissue, both under healthy conditions and when teeth are damaged by caries, as well as to investigate tooth pulp calcification. We developed criteria for the identification of these pathologies. The ratio of the intensities at 1069 and 870 cm−1 remains constant in solid tissues, even in the event of caries formation, while tooth calcifications that include pulp degeneration typically show an increase in the ratio of the intensities at these wave numbers; this increase may be used in the diagnosis of fibrotic pulpite. Enamel typically shows elevated replacement of the hydroxyl group by the (CO3)2− anion in apatite, with reduced substitution of the PO43− anion by (CO3)2−. The opposite process is observed in pathological processes such as caries and calcification.