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

A technology based on fluorescence imaging with reflectance enhancement (FIRE) was validated for early detection of caries.

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 Five teeth were withdrawn after each examination.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.

Earliest lesion depth detected by FIRE, QLF, and VE was 9.09 +/- 0.03 microm. DDp detected from 14.00 microm. 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.