Orange/Red Fluorescence of Active Caries by Retrospective Quantitative Light-Induced Fluorescence Image Analysis

This retrospective clinical study determined the association of caries activity and orange/red fluorescence on quantitative light-induced fluorescence (QLF) images of surfaces that progressed to cavitation, as determined by clinical visual examination. A random sample of QLF images from 565 children (5-13 years) previously enrolled in a longitudinal study was selected. Buccal, lingual and occlusal surface images obtained after professional brushing at baseline and every 4 months over a 4-year period were analyzed for red fluorescence. Surfaces that progressed (n = 224) to cavitation according to the International Caries Detection and Assessment System (ICDAS 0/1/2/3/4 to 5/6 or filling), and surfaces that did not progress (n = 486) were included. QA2 image analysis software outputs the percentage increase of the red/green components as ΔR and area of ΔR (areaΔR) at different thresholds. Mixed-model ANOVA was used to compare progressive and nonprogressive surfaces to account for correlations of red fluorescence (ΔR and areaΔR) between surfaces within a subject. The first analysis used the first observation for each surface or the first available visit if the surface was unerupted (baseline), while the second analysis used the last observation prior to cavitation for surfaces that progressed and the last observation for surfaces that did not progress (final). There was a significant (p