3 Evaluation of early carious lesion activity on deciduous enamel by the quantitative light-induced fluorescence method

Abstract

We examined the effect of hydration on the quantitative light-induced fluorescence of white-spot early carious lesions on the deciduous enamel surface. Surfaces of exfoliated deciduous teeth were cleaned with non-fluoride polishing gel, and a window 2.0×3.0mm was made using nail varnish. The specimens were subjected for 5 days to a pH-cycling model (demineralization for 6h, remineralization for 18h) at 37℃ and then placed in a remineralizing solution for two days. Fluoride dentifrice treatment was performed for one minute twice each day. Quantitative light-induced fluorescence (QLF) images were produced as follows. A wet cotton ball was placed on the specimen for one minute and a wet-specimen image was acquired as soon as the cotton was removed. Dry-specimen images were taken after drying the specimen with compressed air for 10 seconds. Image analysis was then performed to determine the delta F, area and delta Q. Dehydration produced a statistically significant change in all parameters for every group (p<0.05). This difference was greater in the control group than in the fluoride group. These findings suggest that the method of controlled dehydration with QLF may be used to evaluate the activity of early carious lesions in deciduous teeth.