A preliminary investigation of a spectroscopic technique for the diagnosis of natural caries lesions

Objective To report the use of spectroscopic analysis of dental fluorescence excited with a blue InGaN laser diode operating at 405 nm. Method The spectra resulting from three classifications of smooth surface non-cavitated caries lesions (dull, shiny, brown) with 20 samples in each group were examined using the ratio of integrated fluorescence intensity in two spectral bands. Results All lesions demonstrated spectra which were significantly different from sound tooth structure. As expected, the ‘brown’ lesions demonstrated a significantly different spectral profile from the two white spot lesion classifications. Dull and shiny lesions had significantly different spectral measurements when examining the ratio of the integrated fluorescence in spectral bands between 480–500 and 620–640 nm. Conclusion This method has application for detection of dental caries as well as demonstrating potential application to evaluate lesions which may represent different degrees of caries activity.