Fluorescence spectroscopy analysis of light-induced tooth whitening

Tooth whitening treatment is a very common dentistry application for appearance enhancement. The importance of teeth appearance and color has attracted industrial interest in developing many products for consumers and professional users. However, standardizing a protocol for application of these products is difficult due to a high biological variability of the teeth color and structure. This creates a need for an objective method for monitoring of teeth shades. Current objective evaluation comprises colorimetric, spectroscopic, and imaging analysis, mostly based on reflectance and fluorescence techniques. Previous studies monitor total fluorescence intensity for this purpose, since it can take into account the effect of fluorescent agents in dental tissues. On the other hand, few spectroscopic studies investigate the processes that generate the variation in the fluorescence intensity due to staining or teeth whitening. These processes can be understood by using fluorescence spectroscopy, which has potential to be used with fluorescence imaging techniques to improve the assessment of teeth shade. This study aims to use fluorescence spectroscopy as a tool to assess tooth whitening, especially using a recently developed light-induced method using violet LED illumination Our results show a decrease of 37.4% in the total fluorescence intensity between 450 nm and 750 nm after coffee staining After the whitening treatment, this intensity increased 11% compared to the emission before staining Observed spectral changes suggest the changes due to the whitening method used in this study. Also, this illustrates the potential of light-induced whitening for minimally or non-invasive whitening.