Roughness and Color Stability of Different Enamel Shade Resin Composites.

Objectives: The objective of this study was to compare surface roughness and color stability of different enamel shade resin composites after polishing.
Methods: 70 Composite discs (5 mm diameter x 2 mm thickness) were fabricated from different composite systems using a rubber mold and divided in 5 groups(n=14): Estelite Omega EA2 (EO), Filtek Supreme Ultra A2E (FS), IPS Empress Direct A2 Enamel (ED), Forma A2E (FO) and Essentia LE (ES). For each group, the specimens were subdivided into 2 groups(n=7): one without polishing and the other polished by a sequence of stone/silicone polishers. The average surface roughness (S_a) of each specimen were measured in five different areas using a roughness tester. For color stability evaluation, a color measurement of each polished specimen (n=7) was made using a spectrophotometer. Then, for 28 days the specimens were daily immersed in coffee for 15min, rinsed with distilled water and kept in artificial saliva. Color measurements were taken after 1, 7, 14, and 28 days and color change values were calculated. CIELab coordinates were recorded and color difference analysis (ΔE) was made using the CIEDE-2000 formula. All difference between groups were analyzed statistically in a 95% confidence interval.
Results: For S_a, values ranged from 0.25±0.66 (EO) to 0.83±0.91 (FO), but there were no significant differences between groups (p>0.05). For color stability, FO and EO showed the lowest values of DE (8.27±1.59 and 8.90±3.61, respectively), without differences between them. FS showed lower ΔE values (13.88±1.80) than ED (18.36±4.92) and ES (20.51±4.97). There were no significant differences of ΔE between ED and ES.
Conclusions: The resin composites tested in this study showed different behaviors of color stability, with better results for FO and EO, and worse for ED and ES. All composites presented the same statistical values for roughness after polishing.