Fig. 5.

Protocol for obtaining dual laser fluorescence from a tooth. The blue oval indicates a suspicious region to be measured. AF spectra are obtained at intervals of $\sim 2\mathrm{mm}$ along the dashed line, which spans through both sound enamel and the suspected carious lesion. The baseline reading is taken to be in a sound enamel region furthest away from the lesion and the lesion measurement is taken to be the centermost reading within the lesion area.