Gene expression of FAK and α-SMA in hGFs grown on different surfaces. hGFs were seeded on one of the following surfaces: smooth zirconia machined surface (ZrM), moderately rough zirconia surface (ZLA), smooth machined titanium surface (TiM), or moderately rough titanium surface (SLA). Expression of (A) FAK and (B) α-SMA in hGFs grown on ZrM, ZLA, TiM and SLA at 2, 7, and 14 days. Y-axis represents the n-fold expression levels of the target gene in relation to the cells in the TCP group (control) calculated by the 2−ΔΔCt method. Data are presented as mean ± SEM of 8 independent experiments with hGFs of 8 different donors (n = 8), * significant difference between groups as tested by Wilcoxon test (p < 0.05).