| Titanium has been widely utilized in bio-medical field due to its excellent biocompatibility and mechanical properties. Success or failure of an implant depends strongly on the extent to which it is integrated into the surrounding bone in a short time, called osseointegration. Titanium-based implant without surface modified has low biological activities, which caused the long period of osseointegration in clinical application, so the surface of titanium implant should be modified by activation treatment to form rapid and firm establishment of osseointegration.In this study, the sandblasting with large-grit and acid-etching(Trad-SLA) treatment was studied and improved. The modified SLA treatment(Mod-SLA), sandblasting-anodic oxidation treatment(AO-SLA), sandblasting & acid-etching & alkali-etching treatment(AE-SLA) and sandblasting & acid-etching & H2O2-treatment had been developed, and the superhydrophilic surfaces had been successfully attained on smooth α-Ti substrate via these treatments. The properties and durability of specimens’ surfaces were investigated by SEM、EDS、XRD、XPS、AFM and contact angle measurement; The human bone-marrow mesenchymal stem cells(h BMSCs) were used to study the surface in virto osteoblast bioactivity, and to discuss the osteoblasts’ response mechanism on different activated surfaces. Based on the research of the activation treatment on α-Ti, this topic also studied the activation treatment on α+β-Ti surface and gave the optimized modification processing according to the comparative analysis of electrochemical behavior of α-Ti, α+β-Ti and β-Ti in different electrolyte.Mod-SLA used organic acid to substitute inorganic acid solution and formed the macro and micro pits on α-Ti surface, which was the typical topography of SLA treatment, this topography had richer nanoscale structures with a surface roughness of 2.21μm. AO-SLA was a duplex treatment of SLA and anodic oxidation; it formed a three-dimensional nanoscale network porous titanium structure with a surface roughness of 2.14μm, and the surface wettability had increased. Both of these two treatments had formed an anatase Ti O2 layer on the surface of α-Ti substrate. AE-SLA sample had a nanofiber-like feature and a surface roughness of 2.02μm, this treatment had formed a sodium titanate gel layer on the surface and introduced a lot of hydroxyl groups to the surface which made it obtained the durable superhydrophilicity. H2O2-SLA treatment had formed a nanoneedle-like feature on α-Ti surface. Because of the titania gel layer formed on this surface, it showed excellent durable superhydrophilicity, which could maintain superhydrophilicity even been stored in the air for 6 months or more. Vitro experiments indicated that the activated surface could promote cell adhesion to the surface, the superhydrophilic surface which had more nanostructures could not only accelerate the speed of the cells adhere to the surface but also made this adhesion firmly. The surface with more macro-level pore structure and larger surface roughness could better promote the cells’ proliferation while the superhydrophilic surface with a gel layer could better promote the differentiation of the cells. Electrochemical tests showed that α+β-Ti had the best corrosion resistance no matter in mixed inorganic acids or organic acids or alkaline solution, thus adjusted the acid-etching process to obtain a micro-nano composite porous structure on α+β-Ti surface. Due to the corrosion occured preferentially on the boundary of α-phase and β-phase, so there were some nanoscale lamellar structures inside of the pores. After AE-SLA treatment, α+β-Ti formed loose short fibrous structures and showed superhydrophilicity. Anatase and rutile Ti O2 were discovered on α+β-Ti surface after these two activation treatments, which let α+β-Ti obtained the bioactivity. |
PDF Full Text Request