Materials and methods: A total of 40 human sound premolars were randomly divided into two groups according to the materials' assignment either; single-shade or multi-shade composite (n=20), then each group was divided into two subgroups according to the storage medium either; distilled water or coffee (n=10) and then each subgroup was divided into two classes according to the shade either; A2 or A3 (n=5). Circular class V cavities were prepared on labial surfaces of each tooth and teeth were restored using either composites according to the manufacturers' instructions. The color of each tooth and restoration was recorded using VITA Easyshade V following aging and bleaching. The shade difference between the restoration and the tooth was calculated.
Results: Intergroup comparison of ΔE and ΔE00 between both composites have shown significant difference at baseline, one day and 12 days (P ≤ 0.05) within both storage media and shades. Intragroup comparison of ΔE and ΔE00 within Omnichroma or Filtek Z350XT have shown statistically significant effect of time on ΔE (P ≤ 0.016). Intergroup comparison of ΔE and ΔE00 between both composites have shown statistically significant difference before bleaching, immediately after bleaching and after two weeks (P ≤ 0.05) within both shades. Intragroup comparison within Omnichroma or Filtek Z350XT have shown statistically significant difference between different time periods (P ≤ 0.016‏‏).
Conclusions: Multi-shade composite showed superior immediate shade matching ability as compared to the single-shade one. Both materials showed low color stability following aging and poor color matching after bleaching.