Color and translucency of finished and unfinished esthetic restorative materials after staining and bleaching.

To evaluate the effect of staining and bleaching on color and translucency of finished and unfinished nano-filled resin composite and giomer. Twenty specimens (ten finished + ten unfinished) were fabricated from each material, then an initial color and translucency measurement was taken. Specimens were stained in coffee for 48 h at 37 °C, rinsed and dried. After which the second color and translucency measurement was taken. After in-office bleaching with 40% HO Opalescence boost, a third color and translucency measurement was taken. CIE system was used for measuring color change and translucency. Two-way ANOVA and paired -test were used for statistical analysis at P ≤ 0.05. After staining, all specimens showed clinically acceptable color change ( ≤ 3.3) with no significant differences between groups. After bleaching, all specimens showed clinically unacceptable color change ( > 3.3) and significant differences between finished & polished and unfinished groups (P = 0.024). Nano-composites recorded significantly higher translucency than giomer (P = 0.000) except after bleaching. In addition, the translucency of unfinished groups were significantly higher than finished & polished groups (P = 0.001). The tested materials responded similarly to staining and bleaching. High concentration bleaching increased color change and reduced translucency. Finishing & polishing restorative materials improves their resistance to color change after bleaching, but it adversely affects translucency.