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Detection and assessment of incipient caries with quantitative light-induced fluorescence (QLF) has been established. The aims of the present study were to determine (1) the ability of QLF to longitudinally monitor the demineralisation of teeth to produce caries-like lesions and the subsequent remineralisation of the same lesions using artificial saliva, and (2) the effect of plaque on caries detection by QLF. Two experiments (A, B) were devised. In experiment A, 12 bovine teeth were painted with acid-resistant colourless nail varnish except for an exposed window on the buccal surface. The development of caries-like lesions on these teeth, by demineralisation in acidic buffer solution, was assessed every 24 h for 4 days using QLF. Lesions produced were subsequently subjected to remineralisation in artificial saliva (pH 7.2) containing (g/l): MgCl2·6H2O (0.03), K2HPO4 (0.121), KH2PO4 (0.049), KCl (0.625), calcium lactate (3.85), fluoride (0.05 ppm), methyl-p-hydroxybenzoate (2.0) and sodium carboxymethylcellulose (0.4). The degree of remineralisation in each lesion was quantified weekly for 5 weeks using QLF. In experiment B, 14 natural white spot lesions were detected and assessed with QLF while the subjects refrained from oral hygiene to encourage plaque growth for 3 days. In experiment A, the integrated fluorescence change, .Q (%·mm2), increased linearly with increasing demineralisation time and decreased inversely with increasing remineralisation time. There was a significant difference (ANOVA) between the mean of daily readings for the demineralisation (pd0.001) and the weekly readings for the remineralisation (pd0.01). In experiment B, 10 of the 14 lesions were obscured by plaque after 3 days and could not be detected for analysis. In conclusion, QLF can longitudinally monitor the progression and regression of incipient caries lesions; however, the presence of plaque may obscure the detection of such lesions. |