The effect of surface defects in early caries assessment using quantitative light-induced fluorescence (QLF) and micro-digital-photography (MDP).

a b s t r a c t Objectives: The purpose of this study was to consider the impact of surface defects on quantitative light-induced fluorescence (QLF) and micro-digital-photography (MDP) measures, in relationship to lesion depth. Methods: Simulated enamel carious lesions were developed on 45 extracted human teeth. Images of each tooth were captured with both QLF and MDP. The teeth were sectioned and lesion depth was measured with polarized light microscopy (PLM). Pearson correlations were computed using data from the 27 lesions which did not have surface loss, and then separately based upon the 18 lesions which did display surface loss. MDP variables DR and DX measure reflected light, whereas QLF variables DF and DQ measure fluorescence. Results: A strong correlation was identified between lesion depth and DF (r = 0.765, p < 0.0001), and DQ (r = 0.827, p < 0.0001) on intact lesions while a weak but suggestive, although non-significant, correlation was identified between average lesion depth and DR (r = 0.369, p = 0.059) and DX (r = 0.595, p = 0.0011). However, the corresponding correlation was not statistically significant, when lesions with surface loss were considered for QLF and MDP measures. Conclusions: QLF measures DF and DQ were strongly correlated with lesion depth in labsimulated lesions with no surface loss, but not among lesions with surface defects. The two MDP-associated measures, DR and DX, could not be said to differ significantly when lesions with and without surface defects were compared with lesion depth. Because intact lesions can be remineralized, accurate assessment of their status is imperative for caries treatment. Clinical significance: Dental caries is still widely prevalent today. We now know that with early stage detection, remineralization can be accomplished. Being able to identify dental caries in its reversible stage (before physical surface loss) is paramount for the clinician to be able to treat the disease non-invasively.