Effect of surface sealant and staining on the fluorescence of resin composites

Statement of problem. Natural teeth and several commercial resin composites emit a strong blue fluorescence when exposed to ultraviolet (UV) light, which makes teeth whiter and brighter in daylight. Surface sealant and staining may change the fluorescence of resin composites. Purpose. The purpose of this study was to determine the effect of surface sealant application and staining/stain removal on the fluorescence of resin composites. Material and methods. Spectral reflectance and color of 4 resin composites (Filtek Supreme, Gradia Direct, Simile, and Vit-1-escence) were measured with/without application of a surface sealant (BisCover) at baseline and after staining/stain removal (n = 5). A UV filter was used to exclude or include the UV component of illumination. Fluorescence spectra were calculated by subtracting the spectral reflectance values of the UV component excluded condition from those of UV included condition. For staining, specimens were sequentially immersed in mucin, chlorhexidine, and a tea solution. Stain removal vas performed by ultrasonic cleaning and PBS (phosphate buffered saline) immersion. Color difference (Delta E-00) by the UV component was calculated based on CIEDE2000 color system. Delta E-00 due to staining and stain removal were also calculated. Changes in color and fluorescence by the staining and stain removal were analyzed by 2-way analysis of variance (alpha=.05). Results. Sealant application decreased fluorescence of resin composites. After staining, fluorescence was not detected except for 1 composite. After stain removal, a decrease in fluorescence from the baseline was observed, and 2 composites showed significant decrease (P <.05). Conclusion. Fluorescence of resin composites decreased or disappeared after surface sealant application and or staining procedure.