Figure 2. Bar charts comparing the mean color differences (ΔE) with standard deviations of Filtek Ultimate and Herculite XRV Ultra (nanohybrid incremental-fill resin composites) after thermocycling and storage in coffee solution for 1 and 7 days. For the same polishing procedure and resin composite, the groups with the same lower case letters are not statistically different. The polished and unpolished groups connected by a solid bar are not statistically significant.
