Evaluation of Fluorescence Imaging with Reflectance Enhancement for Caries Detection

Objective: A technology based on Fluorescence Imaging with Reflectance Enhancement (FIRE) for early detection of caries was validated, by comparing the earliest caries that FIRE, Quantitative light-induced Fluorescence (QLF), Diagnodent and visual examination (VE) can detect, and the sensitivity/specificity of the methods. Methods: Phase-I: Caries-like lesions were created on a defined area on 70 teeth by 14-day demineralization in acidified gel. During demineralization, teeth were examined daily for caries by VE, FIRE, QLF and Diagnodent. After each examination, 5 teeth were removed every 6h for 24h, thereafter daily. Tooth slice was cut from each lesion and histologically examined under polarizing-light microscope (PLM) for lesion presence/absence and lesion depth quantification. Phase-II: 56 teeth assembled on manikin mouth models were examined twice by two dentists for incipient caries using the four methods. Then 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 relative to PLM was calculated by Kappa statistics. Results: Earliest lesion depth detected by FIRE, QLF, and VE was 9.09±0.03µm. Diagnodent detected from 14.00µm. A-ROC-c were

Methods	Kappa	Sensitivity	Specificity	PPV	NPV
QLF	0.464	.66	.81	.82	.66
FIRE	0.785	.98	.80	.86	.96
FIRE with WL	0.843	.99	.84	.89	.98
VE	0.633	.85	.78	.83	.81
Diagnodent	0.267	0.35	.94	.88	.54

FIRE with white light (WL) = 0.916±0.024, FIRE = 0.886±0.027, VE = 0.816±0.033, QLF = 0.738±0.036, Diagnodent = 0.644±0.031. FIRE (alone or with WL) had significantly (p<0.001) greater A-ROC-c than QLF and Diagnodent. Similar results were observed with subsequent examinations by both Dentists. Conclusion: FIRE can detect incipient caries lesion of <10µm depth. FIRE has a higher accuracy and validity in detecting caries than QLF and Diagnodent.