Influence of enamel thickness on quantification of mineral loss in enamel using laser-induced fluorescence.

The objective of this study was to evaluate the effect of enamel thickness on the quantification of white-spot lesions with laser fluorescence. One hundred and twenty 3-mm-diameter human ground and polished enamel specimens were used. Specimens were illuminated by a 488-nm argon laser, images were acquired through a 540-nm high-pass filter and stored on the Quantitative Light-Induced Fluorescence (QLF) program. Specimens were divided into two groups and demineralized for 48 or 96 h and QLF images were again acquired. Fluorescence radiance (FR) of both sound (FR(s)) and demineralized (FR(d)) enamel was determined using the QLF program. Change in fluorescence radiance (Delta FR, %) was determined as follows: Delta FR = FR(d)/FR(s) x 100. One thin section was obtained for transverse microradiography analysis. Enamel and dentin thickness of the thin sections were measured. There was a good correlation between QLF parameters and enamel thickness. It can be concluded that the FR observed for similar lesions depends on the actual enamel thickness. Copyright 2003 S. Karger AG, Basel