Method: Eight specimens were prepared for each composite resin: FiltekTM Z250, FiltekTM Z350, FiltekTM Z350 XT, Grandio® and experimental with zirconia nanoparticles. Methods: Five human canines (Ethics Committee of Univ. Estadual Paulista – UNESP, Araraquara School of Dentistry, Protocol number: 38/2010) were used as reference. The specimens were made in a metallic mould (10x1mm). LED Celalux® (VOCO) was used with 776 mW/cm2 for 40s. A CCD camera (LG) coupled to objective lens with a system of four LED was used to capture the images. For each specimen, 16 images were captured and the mean values of captured images were obtained, which were converted into gray intensity scale. Analysis of Variance (ANOVA) and Tukey’s test (α = 5%) were used.
Result: Both, FiltekTM Z250 and the experimental composite resins showed the lowest fluorescence mean values, equivalent to each other. The fluorescence mean value for FiltekTM Z350 (0.100; ± 0.006) was higher than FiltekTM Z250 (0.084; ± 0.006), however equivalent to experimental composite resin (0.087;± 0.008). The other composite resins established the following fluorescence mean values: FiltekTMZ350 XT (0.116; ± 0.007) < Tooth (0.162; ± 0.017) < Grandio® (0.210; ± 0.010).
Conclusion: The composite resins did not present fluorescence similar to dental structure.