Fig. 4From: Improved response of human gingival fibroblasts to titanium coated with micro-/nano-structured tantalumRelative cell viability and proliferation assay. a HGFs cultured on both samples for 24 h were stained with Calcein AM (green) and PI (red), indicating live and dead cells (× 100). b Relative HGF viability rate was detected at 24h based on live/dead cell staining. *p < 0.001 when compared with Ti group. c Relative HGFs proliferation rate on both samples was detected by CCK-8 at 1, 3, 5, and 7 days. *p < 0.0001 when compared with Ti groupBack to article page