Influence of Surface Topography and Surface Chemical Modification on Hydrophilicity of Titanium

Abstract

Although various surface modification technologies have been developed to enhance the bioactivity and osseointegration capability of titanium, no consensus has been reached on an effective method. Since the surface wettability of implants plays an important role in the initial adhesion and subsequent behavior of the cells, this study aimed to clarify the effect of surface treatments, including surface topography and surface chemical modification, on the surface wettability （contact angle） of titanium. Several kinds of surface topography were produced by alumina blasting and acid etching, and then surface chemical modification was carried out with oxygen plasma （O2 plasma）, ultraviolet light （UV）, or hydrogen peroxide （H2O2） treatment. Surface contact angle was then evaluated against distilled water. In addition, the sustainability of hydrophilicity of these surface-modified titanium specimens was evaluated for various storage conditions.
The blasted and acid-etched surfaces showed super-hydrophilicity with a water contact angle of almost zero degrees. Super-hydrophilicity was also obtained by O2 plasma and UV treatment regardless of the surface topography. Though this hydrophilicity rapidly decreased over time in air atmosphere, this property was maintained by storage in distilled water. These results were influenced by the amounts of hydrocarbon and hydroxyl group on the titanium surfaces.
From the results of the present study, surface treatments that regulate the surface topography and surface chemical modification for enhancing the hydrophilicity of titanium and storage methods for sustaining the hydrophilicity were obtained.