The purpose of this study was to evaluate the discoloration of two nanohybrids, two microhybrids, and a posterior composite
resin restorative material upon exposure to different drinks - namely tea, cola, coffee, red wine, and water. The colors
of all specimens before and after storage in the solutions were measured by a colorimeter based on CIE Lab system, and the
color differences thereby calculated. Data were analyzed by two-way analysis of variance(ANOVA)and Tukey’s HSD test.
According to ANOVA, the restorative material, staining agent, and their interaction were found to play a statistically significant
role(P=0.0001)in color change. Among the staining agents, water consistently showed the lowest ΔE* value for
all materials, whereas red wine showed the highest ΔE* value. In other words, for all the materials tested, their color
change in staining agents ranked in this increasing order: water < cola < tea < coffee < red wine. In terms of comparison
among the five restorative materials, Filtek P60 and Z250 were observed to manifest less color change than the
nanohybrids and Quadrant LC.