Evaluation of autofluorescence and image of oral pathogens and the tooth.

PURPOSE: To test the applicability of autofluorescence (AF) spectrum and image in the detection and identification of oral pathogens. METHODS: Oral pathogens (Candida albicans, Porphyromonas gingivalis, Streptococcus mutans) and teeth were used. To induce AF, the 405 nm laser was used as a light source, and AF was obtained and observed using a spectrometer, fluorescence camera, and microscope, respectively. RESULTS: The tested oral pathogens had similar spectral distributions, but their peak intensities and peak ratios were different. Their peak positions and spectral patterns were different from those of the tested sound and carious teeth. These differences were also found from the other referenced oral mucosa. Fluorescence image could localize the existence of oral bacteria. Oral pathogens could be imaged by fluorescence, but identification of each pathogen by image was not probable. CLINICAL SIGNIFICANCE: Oral pathogens can be observed and identified from the lesion if autofluorescence spectrum and fluorescence images are combined.