Comparison of Fluorescence of Dental Structure and Composite Resins

Objectives: This study compared the degree of fluorescence between dental structures (enamel and dentin) and 2 composite resins with enamel and dentin shades, by means of a digital image. Methods: We used 2 composite resins (Esthet-X, Dentsply, and Filtek Z-350, 3M/ESPE, at color A2) of enamel and dentin resin and 3 human teeth. The teeth were prepared with 2 sagittal slices 2 mm wide. The palatal enamel and dentin were removed. The tooth section was fixed in the center of an empty stainless steel mold and filled with an enamel resin (vestibular) and dentin resin (palatal). The mold's empty space measured 10 mm x 10 mm x 2 mm. We utilized 3 teeth with each composite resin. The ultraviolet LED source (24.5 mW/cm²) was applied directly to the specimen in a dark room. The degrees of fluorescence of enamel resin, enamel, dentin, and dentin resin were measured with a digital photo, and the image was processed through a computer program developed by São Carlos Physics Institute-Optical Group, USP - Brazil. The computer program rates, in pixels, the degree of fluorescence emitted by specimens. Sixteen records were made for each specimen, and the results were subjected to two-way Analysis of Variance (ANOVA). Results: The results obtained between composites were, for enamel resin and enamel, 1.32 and 1.66, and for dentin and dentin resin, 0.97 and 0.66, respectively. The result for dentin and enamel was 1.10. Conclusions: The fluorescence intensity of the 2 enamel resins was greater than that of the enamel, while the dentin resins had less fluorescence than dentin. However, dentin fluorescence was greater than that of enamel. Enamel resins must thus possess minor fluorescence intensity, and dentin resins must be incorporated into more fluorescent substances.