Clinical study on caries risk assessment using quantitative light-induced fluorescence

Objective: The present study was to determine clinically the possibility of caries risk assessment of white spot lesions using quantitative light-induced fluorescence (QLF) technique. Methods: The study was approved by the Ethics Committee at Osaka Dental University Hospital prior to recruiting patients. 65 patients gave their informed consent before being accepted into the study during the one-year study period. No instructions about dietary habits were given to the patients. The patients were examined by four times at 3, 6 and 12 months after the initiation of the trial. QLF images were taken on the single designated white spot lesion in each patient by using QLF system (Inspektor Research, The Netherlands). Each image was analyzed by four measuring parameters which were: average fluorescence loss (%), ΔF; maximum fluorescence loss (%), ΔMax; lesion size (mm²), S; and mineral loss (%mm²), ΔQ. For caries risk assessment each white spot lesion was divided by using the QLF parameter in three lesion types; progressive, regressive, and arrested, at 3, 6 and 12 months later as compared with baseline. Results: 95% of the progressive lesions (ΔQ) at 3 month later were still progressive lesions at 6 month later (Kappa=0.548), and 81% were at 12 month later (Kappa=0.263). 88% of the progressive lesion (Δmax) at 3 month later were progressive lesions at 6 month later (Kappa=0.546), 84.6% were at 12 month later (Kappa=0.508). Conclusion: The QLF technique could monitor the white spot lesions with regression, progression or arrest and assess the caries risk with monitoring white spot lesions for one year. We suggested that QLF could be a suitable technique clinically for caries risk assessment at the stage of white spot lesion.