Biological Properties Of Cu-TiN Coated Titanium Alloys By Mg/Ca Ions Implantation

With the development of technology,it is possible to replace necrotic teeth by dental implants.Titanium alloy(Ti-6Al-4V)has been widely used in dental implants due to its good mechanical properties,corrosion resistance and biocompatibility.At the same time,it has shortcomings such as low antibacterial,toxic ions(Al³⁺,V⁴⁺)precipitation and so on.In order to improve the success rate of implanting Ti-6Al-4V into human body,in this study,magnetron sputtering system was used to prepare Cu-TiN composite film on Ti-6Al-4V to achieve long-term antibacterial effect and prevent the precipitation of toxic elements.Then Mg and Ca ions were implanted into Cu-TiN respectively via plasma immersion ion implantation(PIII)system to further compare the proliferation of bone cells on them.Next,the optimum dosage of Mg⁺implanted Cu-TiN(Mg⁺Cu-TiN)was further studied to select the best synergistic effect on osteoblast growth and antibacterial property of Ti-6Al-4V.In the first part of this paper,Cu-TiN composite film coated with the same content of Mg or Ca was prepared(Mg⁺Cu-TiN;Ca⁺Cu-TiN).X-ray photoelectron spectroscopy(XPS)was used to analyze the elemental composition of the coatings.Scanning electron microscope(SEM)and atomic force microscope(AFM)were used to observe the surface morphology and roughness of samples.Inductively coupled plasma atomic emission spectrometry(ICP-AES)was used to detect the amount of ions precipitation.The cytocompatibility of the samples was evaluated by MC3T3-E1 cells and L929 cells.Escherichia coli(E.coli)was used to evaluate the antibacterial activity in vitro.The results show that Cu-TiN can effectively improve the antibacterial activity of Ti-6Al-4V.Compared with Ca⁺Cu-TiN,the Mg⁺Cu-TiN has better cytocompatibility,protein adsorption capacity and antibacterial activity under the same concentration of Mg or Ca.In the second part,on the basis of previous research,Mg was further implanted into Cu-TiN composite film at different concentrations(Mg⁺Cu-TiN-1;Mg⁺Cu-TiN-2;Mg⁺Cu-TiN-3).MC3T3-E1 cells were used to evaluate the cytocompatibility of the samples.Staphylococcus aureus(S.aureus)was used for long-term antibacterial experiment.Atomic force microscopy(AFM)was used to observe the surface morphology and roughness of samples.So as to explore the effects of Cu-TiN composite films with different Mg contents on the biocompatibility and antibacterial properties.The result shows that the sample with the least Mg content(Mg⁺Cu-TiN-1)has the best cell proliferation ability,and the sample with the most Mg content(Mg⁺Cu-TiN-3)has the best long-term antibacterial ability.In conclusion,Cu-TiN can effectively inhibit the growth of E.coli and S.aureus.Mg implantation is conducive to the spread and proliferation of cells.A small amount of Mg implantation is more beneficial to improve the comprehensive performance of the samples.This study provides a greater possibility for the clinical use of Ti-6Al-4V in dental clinic.