Ferraris Sara, Warchomicka Fernando, Iranshahi Fatemeh, Rimondini Lia, Cochis Andrea, Spriano Silvia
Department of Applied Science and Technology, Politecnico di Torino, 10129 Torino, Italy.
Institute of Materials Science, Joining and Forming, Graz University of Technology, A-8010 GRAZ, Austria.
Materials (Basel). 2020 Jan 15;13(2):409. doi: 10.3390/ma13020409.
Soft tissue adhesion and infection prevention are currently challenging for dental transmucosal or percutaneous orthopedic implants. It has previously been shown that aligned micro-grooves obtained by Electron Beam (EB) can drive fibroblast alignment for improved soft tissue adhesion. In this work, evidence is presented that the same technique can also be effective for a reduction of the infection risk. Grooves 10-30 µm wide and around 0.2 µm deep were obtained on Ti6Al4V by EB. EB treatment changes the crystalline structure and microstructure in a surface layer that is thicker than the groove depth. Unexpectedly, a significant bacterial reduction was observed. The surfaces were characterized by field emission scanning electron microscopy, X-ray diffraction, confocal microscopy, contact profilometry, wettability and bacterial adhesion tests. The influence of surface topography, microstructure and crystallography on bacterial adhesion was systematically investigated: it was evidenced that the bacterial reduction after EB surface treatment is not correlated with the grooves, but with the microstructure induced by the EB treatment, with a significant bacterial reduction when the surface microstructure has a high density of grain boundaries. This correlation between microstructure and bacterial adhesion was reported for the first time for Ti alloys.
对于牙科经粘膜或经皮骨科植入物而言，软组织粘连和感染预防目前颇具挑战性。此前已有研究表明，通过电子束（EB）获得的排列微槽可促使成纤维细胞排列，从而改善软组织粘连。在这项研究中，有证据表明同样的技术在降低感染风险方面也有效。通过电子束在Ti6Al4V上获得了宽度为10 - 30 µm且深度约为0.2 µm的微槽。电子束处理改变了比槽深更厚的表面层的晶体结构和微观结构。出乎意料的是，观察到细菌数量显著减少。通过场发射扫描电子显微镜、X射线衍射、共聚焦显微镜、接触轮廓仪、润湿性和细菌粘附试验对表面进行了表征。系统地研究了表面形貌、微观结构和晶体学对细菌粘附的影响：结果表明，电子束表面处理后的细菌减少与微槽无关，而是与电子束处理诱导的微观结构有关，当表面微观结构具有高密度晶界时，细菌数量会显著减少。这种微观结构与细菌粘附之间的相关性首次在钛合金中得到报道。
