REPRODUCIBILITY AND ACCURACY OF 3 METHODS FOR ASSESSMENT OF DEMINERALIZATION DEPTH ON THE OCCLUSAL SURFACE - AN IN-VITRO EXAMINATION

This laboratory study of 100 occlusal surfaces investigated the reprod ucibility and accuracy of a visual ranked caries scoring system, an el ectronic caries scoring system (ECM) using a continuous conductance sc ale, and a radiographic ranked caries scoring system. Histological exa mination of the teeth served as a gold standard to validate the abilit y of each system to assess lesion depth and predict softened, deminera lized dentine. After training, 3 examiners carried out each scoring sy stem on two separate occasions. Kappa values for visual, ECM and radio graphic ranked scoring systems showed good inter- and intra-examiner r eproducibility levels and acceptable limits of agreement for ECM readi ngs. When scoring systems were tabulated against histological scores t here was a high correlation between the visual and ECM methods and les ion depth in both enamel and dentine, but radiographic examination cou ld not detect enamel caries. When compared to the histological scoring , the Spearman correlation coefficients for the visual scoring ranged between 0.87 and 0.93, for the ECM between 0.80 and 0.85 and for the r adiographic scoring system between 0.76 and 0.78. No tooth scored as v isually sound had histological evidence of dentine caries. Soft dentin e corresponded to demineralization involving the middle third of the d entine or more which was related to visual cavity formation or an ECM reading above 9 (score 3 or 4). The radiograph was an excellent predic tor of soft dentine. Tn conclusion, the new visual system appears prom ising, but takes time to learn. The reproducibility and accuracy for t he ECM is acceptable while radiographs miss early occlusal lesions.