Autofluorescence of healthy and inflamed human pulpal tissues was observed by confocal laser microscopy. In this preliminary study, photodynamic diagnosis (PDD) was applied to diagnose pulpal disease. The ability to accurately diagnose pulpal pathology prior to pulpectomy would be very beneficial. Clinically, however, we are unable to perform biopsy to detect pathological changes. Therefore, this study was performed using healthy, acutely and chronically inflamed human pulpal tissues to detect pathological changes in pulpal tissues. Following excision, pulpal tissues were rapidly frozen and standard cryosections were prepared. Autofluorescence of pulpal tissues was observed using a confocal laser microscope to examine whether there were any differences in autofluorescence intensities between healthy and inflamed pulpal tissues. Several combinations of excitation and detection wavelengths were tested to observe autofluorescence from pulpal tissues; the excitation wavelengths ranged from 488nm to 633nm, and the detection wavelengths were longer than 505 nm.
Autofluorescence was detected in both healthy and inflamed groups. With this technique, it may be possible to diagnose pulpal pathology without biopsy, and might be applicable to photodynamic diagnosis (PDD) and photodynamic therapy (PDT) in root canal treatment.