Prospects for applying fluorescence spectroscopy to diagnose the hard tissues of a tooth.

This article deals with the autofluorescence spectra from the hard tissues of a tooth, both in norm and pathology. An investigation was made on 30 extracted human teeth. The measurements were made both for the intact hard tissues of a tooth, such as enamel, dentine, cementum, and root canal, and for the tissues pathologically affected by a caries (superficial, intermediate, and deep) and by a dental calculus. It was found that the fluorescent spectra from enamel, dentine, cementum, and from the regions affected by a caries and dental calculus were identical in form. All the spectra revealed a maximum near 700 nm. However, the intact and affected hard tissues were greatly different in the integral fluorescent intensity. Dental calculus was found to produce the most pronounced fluorescent intensity, whereas the carious regions produced a slightly weaker fluorescent intensity. On the contrary, the intact hard tissues of a tooth exhibited the poorest fluorescent intensity.