| abstract |
A method and apparatus for detecting the presence of caries in human teeth using visible luminescence. A region to be examined is excited with a beam of monochromatic light. The intensity of the visible light emitted from the region is measured at two predetermined wavelengths, one where the intensity dependence of the spectra is about the same for caries and noncaries and the other where the relative intensity increases significantly in the presence of caries. A signal corresponding to the difference in the two intensities is obtained and then displayed. By first determining the magnitude of the difference signal at a nondecayed region, any increases in the magnitude as other regions are probed indicate the presence of caries. The invention is based on the discovery that the visible luminescence spectra for decayed and nondecayed regions of a human tooth are substantially different and that the differences are such that visible luminescence from teeth can be used to detect the presence of caries. |