Color stability of bulk-fill composites exposed to different beverages and the effect of whitening dentifrices

Abstract

Objectives: Discoloration of resin-based composites by colored solutions is a common problem in dentistry and use of whitening dentifrices is becoming increasingly popular. However, it is not clear if whitening dentifrices can remove stains from bulk-fill composite resins. Material and Methods: we evaluated the discoloration of two bulk-fill composite resins (3M Filtek Bulk Fill, Tetric EvoCeram Bulk Fill) aged using 10,000 thermocycles (5°C-55°C) and on exposure to several common beverages, including cola, coffee, red wine, and water, and the amount of reduction of discoloration after brushing with whitening dentifrices. The colors of all specimens before and after storage in the solutions and after brushing were measured by colorimetry based on the CIE Lab system and the differences in color calculated. The data were analyzed by two-way analysis of variance and Tukey's honest significant difference test. Results: The restorative material, staining agent, and the interaction between these two factors were found to play a significant role in color changes. Water consistently showed the lowest ΔE* value of all the staining agents, red wine showed the highest ΔE value with Tetric EvoCeram Bulk Fill, and coffee showed the highest ΔE value with Filtek Bulk Fill. After staining, brushing with whitening dentifrices (Crest 3D White, Crest 3D White Accelerator) was associated with decreased ΔE values compared with those obtained after staining, but with no significant difference between the dentifrice groups (p>0.05). Conclusions: Although whitening dentifrices cannot remove all discoloration of composites caused by common beverages, they can be used to reduce it.