The effect of bleaching on the color stabil-ity and microhardness of tooth-colored restorative materials

الملخص EN

Aims : This study investigated the effect of two home- bleaching regimens (7.5 % hydrogen peroxide, 16 % carbamide peroxide) on the color change and micro hardness of micro hybrid composite (Compo-san) and hybrid composite (TetricCeram) and RMGIC (Vivaglass).

Materials and Methods : Thirty six disk– shaped specimens (5 × 2 mm) (of each restorative material for each test) were prepared and did-vided into three subgroup (n = 12).An unbleached group was used as control, while the remaining spec-imens in the two subgroups were bleached with bleaching regimens.

Color change was assessed by using Vita Easy shade device, and the micro hardness was determined by a Vickers micro hardness tester.

Means values were compared statistically with one way analysis of variance (ANOVA) followed by Duncan's Multiple Rang Test to determine the significant differences among the tested groups at (p = ≤ 0.05) level of significance.

Results : TetricCeram displayed unacceptable color change after bleach-ing with(16 % carbamide peroxide) bleaching regimen.

Decreasing in micro hardness of Vivaglass after bleaching regimens, and micro hardness of Composan after16 % carbamide peroxide.

Conclusion : The 16 % carbamide peroxide bleaching regimen has significant effects on color change of TetricCeram and decreasing micro hardness of Vivaglass and Composan restorative materials.