Surface structuring by Electron Beam for improved soft tissues adhesion and reduced bacterial contamination on Ti-grade 2

Even if soft tissue adhesion on titanium surfaces is an issue of great interest for transmucosal dental implants and percutaneous devices, few specific surface modification strategies have been approached so far to face it. Topographical surface modification is an interesting strategy because quality of soft tissues can be effectively improved by contact guidance effect on fibroblasts. Conversely, biofilm formation is encouraged in presence of rough or porous surfaces, as well as of surface patterns, if the roughness overcome the threshold of 0.2 mu m. This issue becomes particularly critical in medical devices which cross different biological tissues and, through soft tissues, establish a direct contact with the external environment. In the present research, three different grooved patterns (5, 10 and 30 mu m wide) were produced on commercially pure titanium by means of Electron Beam (EB) structuring maintaining the average surface roughness lower than 0.2 mu m. The EB surface structured samples were characterized by means of optical and atomic force microscopy, contact and non-contact profilometry, X-Ray Diffraction, residual stress measurements as well as bacteria and cell adhesion tests. The 10 mu m wide grooves resulted able to support fibroblast alignment onto the metallic substrate. Unexpectedly, all the EB surface structured surfaces not only did not enhance, but even reduced bacterial adhesion up to 48 h culture.