Fig. 9From: Establishment of perpendicular protrusion of type I collagen on TiO2 nanotube surface as a priming site of peri-implant connective fibersThe comparison of relative cell amount on each group surface. Relative amount of epithelial cell on each group surface. Error bars means represent mean ± SD for n = 3, *P < 0.05, **P < 0.01Back to article page