. 2020 Jan 10;45(1):e12. doi: 10.5395/rde.2020.45.e12

Table 3. Mean values of roughness before and after bleaching with carbamide peroxide, hydrogen peroxide, and distilled water (control) for all materials used.

Materials	Before bleaching	After bleaching with 16% carbamide peroxide	After bleaching with 35% hydrogen peroxide	Control
Opallis	0.037 ± 0.007^b	0.048 ± 0.029^a	0.032 ± 0.003^b	0.035 ± 0.004^b
Opallis + BisCover	0.030 ± 0.007^a	0.032 ± 0.005^a	0.030 ± 0.004^a	0.026 ± 0.004^a
Supreme XT	0.028 ± 0.005^a	0.029 ± 0.004^a	0.029 ± 0.002^a	0.027 ± 0.005^a
Supreme XT + BisCover	0.027 ± 0.006^a	0.029 ± 0.005^a	0.029 ± 0.003^a	0.026 ± 0.005^a
Enamel	0.059 ± 0.017^a,b	0.067 ± 0.013^a	0.048 ± 0.008^b	0.071 ± 0.008^a

Data shown are mean ± standard deviation.

^a,bLowercase superscripts indicate statistically significant differences (p < 0.05) between values in the same row.