Table 2. Surface roughness parameters and surface area differences of the Ti samples.
| Materials | Optical profilometry |
AFM | ||
|---|---|---|---|---|
| Ra (nm) | Rq (nm) | Rmax (μm) | Surface area difference (%) | |
| As-received | 27 ± 2 | 34 ± 3 | 0.4 ± 0.04 | 0.02 ± 0.01 |
| eCG | 146 ± 8 | 190 ± 10 | 2.5 ± 0.3 | 2.35 ± 0.6 |
| eFG | 91 ± 8 | 125 ± 11 | 2 ± 0.2 | 1.38 ± 0.4 |
| eUFG | 209 ± 15***,†,‡ | 279 ± 20***,†,‡ | 3.2 ± 0.1***,‡,** | 3.37 ± 1* |
Ra is the average roughness of the absolute value of the profile height; Rq is the root mean square roughness of surface; Rmax is the height of the highest peak in the roughness profile. * if p < 0.05, and *** if p < 0.001 compare with the as-received substrate; ** if p < 0.01, and † if p < 0.001 with respect to the eCG substrates; and ‡p < 0.001 compared to the eFG substrates. There is no statistically significant difference in surface area difference between the eUFG, eFG, and eCG.