Evaluation of fluorescence imaging with reflectance enhancement technology for early caries detection

Purpose: A technology based on fluorescence imaging with reflectance enhancement (FIRE) was validated for early detection of caries. Methods: In Phase-I, caries-like lesions were created in a defined window on 85 teeth by 14-day demineralization in acidified gel. During demineralization, teeth were examined for caries every 6 hours for 24 hours, and thereafter daily by visual examination (VE), FIRE, Quantitative light-induced Fluorescence (QLF), and DIAGNOdent pen (DDp). Five teeth were withdrawn after each examination. A tooth slice was cut from each window and examined under polarizing-light microscopy (PLM) for lesion presence/absence and lesion depth quantification. In Phase-II, 56 teeth assembled on mouth models were examined twice by two dentists for caries using the four methods. Each scored area was examined with PLM. Using Dentist-1/Examination-1 data, the Areas under Receiver Operating Characteristics curves (A-ROC-c) defined by each diagnostic method were compared using Chi-squared tests. Using same data, the validity of each diagnostic method in detecting caries relative to PLM was calculated by Kappa statistics. Results: Earliest lesion depth detected by FIRE, QLF, and VE was 9.09±0.03 μm. DDp detected from 14.00 μm. A-ROC-c were significantly (P< 0.001) greater with FIRE compared with QLF and DDp. Similar results were observed with subsequent examinations by both dentists. Sensitivity, specificity and validity of each method are: FIRE (0.98, 0.80, 0.79), QLF (0.66, 0.81, 0.46), DDp (0.35, 0.94, 0.23) and VE (0.78, 0.85, 0.63), respectively.