Reinhardt JW, et al. - To assess whether or not a composite resin stained by coffee or wine could be lightened to a clinically noticeable degree by some at-home tooth-whitening therapies, researchers in this laboratory study stained a composite resin to a visibly discernible level using both coffee and red wine over 14 days (change was considered clinically noticeable and significant when ΔE_ab*≥2.7) and measured the color change at 1, 7 and 14 days of the staining. While comparing the final composite color with that measured at baseline, they noted that Opalescence returned composite color to an acceptable level after exposure to both staining solutions (ΔE_ab*<2.7), for wine-stained composites, Whitestrips returned color close to the baseline, and HD paste and polishing permitted residual stain to remain (ΔE_ab*2.7).