In vitro performance of QLF system and conventional methods for detection of occlusal caries around tooth-colored restorations in primary molars.

Background: Secondary caries is the main reason for restoration replacement, and therefore, an accurate detection of this type of condition is fundamental.

Objective: To compare in vitro the performance of different conventional and quantitative light-induced fluorescence-based (QLF) methods in detecting occlusal caries around resin composite restorations in primary molars.

Methods: Two examiners evaluated independently 42 sites adjacent to tooth-colored restorations using visual inspection (ICDAS-CARS), radiographic examination, and QLF. Histological examination was used as reference standard method. Area under the ROC curve (Az), sensitivity, specificity, and accuracy of the methods were calculated at enamel (D1) and dentin caries (D3) lesions thresholds. Intra- and interexaminer reproducibility were calculated using intraclass correlation coefficient (ICC) and kappa statistics.

Results: There was no difference among the methods considering Az at D1 threshold. Visual inspection, radiograph, and QLF (scores) methods presented similar sensitivities and significantly higher than those obtained with the QLF (∆F%). At D3 threshold, there were no differences among the methods regarding sensitivities, specificities, and accuracy, except for the examiner 2 with the QLF (∆F%) who achieved a very low sensitivity value.

Conclusions: Conventional methods are similar to QLF methods for detecting caries around tooth-colored restorations in primary teeth.