Methods: Nineteen human enamel samples were ground to form flat enamel surfaces and then the samples were coated with a transparent nail varnish leaving 1.5 x 1.5 mm square windows. These were immersed in 0.1M lactic acid (pH 4.5) up to 48 hours at 370C to produce artificial white spot lesions. Finally, the white spot lesions were measured for averaged green fluorescence reduction rate ΔF (%) by the QLF-D equipped with the double layer filter for QLF-D or conventional filter applied to the conventional QLF system (Inspektor Pro, Inspector Research Systems bv, The Netherlands) .
Results: The ΔF values by the QLF-D for demineralized human enamel indicated statistically significant correlation coefficients at r=0.97 (p<0.01) compared with the conventional QLF system.
Conclusions: It was concluded that the novel SLR-based high-resolution QLF-D system was compatible with the conventional QLF for ΔF values measured in white spots formed in human enamel surfaces.