The effect of initial etching sites on the morphology of TiO2 nanotubes on Ti-6Al-4V alloy

10.1149/2.0011511jesAnodization was performed in phosphate and fluoride containing electrolytes at different pH and sweep rates with the aim of analyzing the variation in current density during the process continuously. The effect of pH and sweep rate on the morphology of titanium dioxide (TiO2) nanotubes, grown on Ti-6Al-4V alloy, has been explicitly examined in this study. At the same time a microscopic analysis of the different stages of the formation of the nanotubes was performed. A new perspective to the growth mechanisms of the nanotubes was brought about in this study. The morphology of the nanotubes was closely related to the density of initial etching sites

Antibacterial coating made of strongly adhered nanosilver to titania nanotubes for dental implants

Objectives: An antibacterial and biocompatible coating on Ti-6Al-4V alloy was synthesised. A method of making the antibacterial effect long term, without any acute release of silver from a dental implant, on insertion was devised.Methods: Titania nanotubes were grown on Ti-6Al-4V alloy using anodisation in the presence of phosphate and fluoride ions. Following alkali treatment of the latter surface, silver nanoparticles were chemically reduced on the nanotubes. The latter surface was then characterised using high resolution electron microscopy (SEM) in association with energy dispersive X-Ray Spectroscopy (EDS) and Raman Spectroscopy. A silver release test was performed. Following a toxicity test in the presence of Human Osteoblast Cells, the biocompatibility of the coating would be assessed.Results: Initially, titania nanotubes with diameter of c. 100 nm were formed following the deposition of silver nanoparticles (10-25nm) on the outer and inner walls. The chemical structure of the nanoparticles was confirmed by Raman Spectroscopy and EDS. The results also highlighted the different bonding attaching the nanosilver to the walls. Subsequently a very low amount of silver was released from the coating during the beginning of the silver release test confirming a good adherence between the nanosilver and the nanotubes. The low leaching was expected to reduce the toxicity of the implant in general and it was confirmed by growth of human osteoblast cells on the coating.Conclusions: The strong adhesion of silver nanoparticles validated the fact that the coating on titanium alloy can prevent an acute release of silver as such having the possibility of having a long term antibacterial effects. This work gave rise to a novel method of synthesising an antibacterial coating for dental implants

Tailoring the interfacial adhesion of anodised TiO2 nanotubes on Ti-6Al-4V alloy for medical implants

Self-assembled nano-structure on the surface of bone/dental implants has attracted significant interest in the last few decades. In this context, anodic TiO2 nanotubes have been shown to have a beneficial effect on osteoblast differentiation and bone formation around implant [1-2]. However, there is uncertainty about the interfacial adhesion to substrate as a surface coating for medical implants [3]. In this study, the effects of anodising conditions on the morphology, composition and interfacial adhesion of the nanotubes grown on titanium alloy were investigated with various electrolytes, pH values and voltage seep rate