Color Stability of Bulk-Fill Resin Composites after Immersion in Different Media

The aim of this study was to evaluate the color stability of bulk-fill and conventional resin composites with respect to different storage media and thickness of composites. FiltekTM Z250 and FiltekTM Z350XT were evaluated as conventional resin composites. FiltekTM Bulk-fill Posterior Restorative and Tetric N-Ceram Bulk Fill were evaluated as bulk-fill resin composites. CIE L*a*b* values of baseline were measured after 24 hours of storage in distilled water, and each resin composite group was divided into three subgroups and stored in distilled water, red wine, and coffee media respectively. Again after 1, 7 and 28 days of immersion, color changes (ΔE*) were calculated using the CIE L*a*b* values. The greatest ΔE* was observed in red wine for all resin composites, and the mean color changes were ranked in the increasing order of distilled water, coffee, red wine. FiltekTM Z350XT exhibited the greatest color change in all media, followed by FiltekTM Bulk-fill Posterior Restorative. FiltekTM Z250 and Tetric N-Ceram Bulk Fill followed with similar mean color change values. According to the 2 different thicknesses of 2 mm and 4 mm of bulk-fill resin composites, there was no thickness-related difference on color changes.