Surface roughness of CP-Ti, Ti6Al4V and sputtered Ti specimen after oxygen plasma treatment for different lengths of time, respectively.

<p>Star sign means significant difference (<i>p</i> < 0.05).</p

Normalized XPS spectra of (a) CP-Ti, (b) Ti6Al4V and (c) sputtered Ti before and after oxygen plasma treatment for different lengths of time.

<p>Normalized XPS spectra of (a) CP-Ti, (b) Ti6Al4V and (c) sputtered Ti before and after oxygen plasma treatment for different lengths of time.</p

Water contact angles of CP-Ti and Ti6Al4V specimen treated by oxygen plasma.

<p>Water contact angles of CP-Ti and Ti6Al4V specimen treated by oxygen plasma.</p

Surface roughness of CP-Ti, Ti6Al4V and sputtered Ti specimen after oxygen plasma treatment for different lengths of time, respectively.

<p>Star sign means significant difference (<i>p</i> < 0.05).</p

Topographic images with section analysis of sputtered Ti substrates: (a) untreated, (b) OPT for 5 minutes, (c) OPT for 10 minutes and (d) OPT for 30 minutes.

<p>Topographic images with section analysis of sputtered Ti substrates: (a) untreated, (b) OPT for 5 minutes, (c) OPT for 10 minutes and (d) OPT for 30 minutes.</p

The results of MTT assay of CP-Ti and Ti6Al4V.

<p>In CP-Ti groups, star sign means significant difference; as well as Ti6Al4V groups, different letter meant statistic different. (<i>p</i> < 0.05).</p

The F-actin immunofluorescence staining of MG-63 cell line cultured on CP-Ti and Ti6Al4V (200x).

<p>(a) is CP-Ti, and (b) is Ti6Al4V. The blue ovoid to round dots was the portion of cell nuclei. The cell shape of CP-Ti Control was polygonal, as well as spindle shape of other groups. All cells cultured on Ti6Al4V displayed spindle shape.</p