| |
The use of quantitative light-induced fluorescence (QLF) to detect and assess early enamel lesions has been established. However, the influence of saliva and the variation in the thickness (buccolingual width) of the teeth as obtained within the dental arches, on the reproducibility of QLF has not been investigated. The aims of the present study were to determine the effect of (1) the presence of saliva, and (2) the variation in the thickness of tooth, on QLF assessment of early enamel lesions. QLF measures the percentage fluorescence change of a demineralised enamel with respect to sound enamel. Two experiments were devised. In experiment 1, artificial caries created on fifteen incisors, using acidified gel system for one week, were analysed under 3 different conditions: A = dry; B = wet with water, and C = covered by a film of saliva. In experiment 2, artificial caries were produced on fifteen molar teeth as in experiment 1, and with step-by-step reduction of the buccolingual thickness of the teeth, the lesions were analysed at varying tooth thickness (mm) of 8, 6, 4.5, 3, and 1.5. In experiment 1, there was a significant difference (paired ttest, pd0.001) in fluorescence change (%) under condition A (-35.1B6.0) when compared with B (-10.0B3.0) and C (-11.6B3.8). The fluorescence change under B and C was not significantly different. In experiment 2, no significant difference (ANOVA) was observed in fluorescence change among the various thickness groups 8 = -20.0B5.2, 6 = -21.7B4.0, 4.5 = -21.5B4.1, 3 = -21.3B4.2, 1.5 = -20.7B4.7. It was concluded that the condition of the surface of the carious lesion (dry or wet with saliva) influences analysis with QLF and, hence for clinical studies a standard condition must be chosen and maintained throughout the studies. Variation in the thickness of teeth over the range investigated does not influence caries assessment with QLF. |