Evaluation of Fluorescence Property of New Direct-filling Resin Composite

Objectives: Important properties of resin composite are not only mechanical properties but also aesthetics. Since natural teeth absorb ultraviolet light and emit fluorescence, fluorescence is as important as shades to obtain the aesthetics of resin composite. Recently, light sources in the near ultraviolet region (for example, purple light: 405 nm) are increasing because of development of LED lights, it is necessary to control the fluorescence of the resin composite in this environment. In this study, we evaluated fluorescence properties of new direct-filling resin composite trial GNX108 and other products.
Methods: GNX108 (GC), Filtek Supreme Ultra (3M), Tetric EvoCeram (Ivoclar Vivadent), and ceram X (Dentsply Sirona) were evaluated in this study. Fluorescence properties were evaluated by spectrum measurement. Material was filled in a mold (φ10 mm × 1 mm height) and light-cured by G-light Prima II Plus (GC). The fluorescence of specimens and 1 mm sliced natural tooth at ultraviolet (365 nm ) and near-ultraviolet (405 nm) excitation were measured by SpectraMax M2 (Molecular Devices).
Results: Each product showed maximal fluorescence at 445 and 460 nm, which was similar to that of natural tooth. This result indicates that the fluorescence colors are similar in all cases. Focusing on the fluorescence intensity, each product showed significantly different intensity. GNX108 was the only material having the similar fluorescence properties at both ultraviolet and near-ultraviolet environment to natural tooth. The intensity of Filtek Supreme Ultra and ceram X is significantly lower in the ultraviolet environment, and the intensity of Tetlic EvoCeram is significantly higher in the near-ultraviolet environment than that of natural tooth.
Conclusions: These results indicate that GNX108 is a material having ideal fluorescence similar to that of natural tooth and may enable higher aesthetics restoration.