A New Method for Caries Diagnosis by Characteristic Spectrum

A new and non-invasive method adapted for optical diagnosis of early caries is proposed by researching on the interaction mechanism of laser with dental tissue and relations of remitted light with optical properties of the tissue. This method without light filter, differed from the DIAGNodent^reg and PNC method in its ability for registering fluorescence spectrum. The characteristic spectrum of dental tissue contains rich information about caries components, structure, spatial conformation, and so on. The research was conducted in vitro, and three components of characteristic spectrum are analyzed: backscattering, reflection and auto-fluorescence. It enables not only to evaluate chemical changes in tooth by analyzing characteristic frequencies of auto-fluorescence spectrum, but also to estimate structure and morphological changes in tissue by means of anti-stokes fluorescence spectrum. Preliminary results show that this method has a potential application in the quantitative diagnosis of various stages of dental caries and high sensitivity for detecting early caries and the surface damage of health enamel.