A New in vivo Method for Measuring Caries Activity Using Quantitative Light-Induced Fluorescence

The aim of this in vivo study was to assess the association between caries prevalence and activity parameters and the properties of etched sites measured with quantitative light-induced fluorescence (QLF). In a clinical method, two areas of a deciduous tooth were etched in each of 44 children (mean age 8.23 years ± 1.45) with 36% phosphoric acid gel for 1 min and 4 min, respectively. ΔQ of the etched site was measured immediately after the etching (ΔQ1) and 24 h later (ΔQ2) with QLF. In addition, deft/DMFT, approximal plaque (API), bleeding on probing (mod. PBI), active carious lesions and currently used fluorides were recorded. In a regression analysis for the deft, the use of fluoridated salt (standardized coefficient SC = –0.25) and fluoride gel (SC = –0.37) showed the greatest effect, as did the fluoride gel (SC = –0.26) and gingival bleeding (SC = 0.50) for the number of active carious lesions. The deft and the number of active carious lesions correlated significantly (r = 0.70, p 1 and ΔQ2 showed a significant statistical correlation with the age-adjusted deft (0.39