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Objective@#To prepare a copper-nobium antibacterial coating on a titanium surface by a microarc oxidation-microwave hydrothermal two-step method and to study its surface structure and antibacterial properties.@*Methods@#Using titanium coated with a microarc oxidation coating (MAO group) as the substrate, copper and niobium were introduced by a microwave hydrothermal method in low (MHL-Cu group), medium (MHM-Cu group) and high (MHH-Cu group) copper chloride solutions and niobium oxalate (MH-Nb group) solutions, respectively. The component with the highest copper content was determined by energy spectrum analysis, and the copper-niobium composite coating (MH-Cu/Nb group) was prepared by microwave hydrothermal mixing with niobium oxalate. The microstructure, element distribution and phase composition of the specimens were characterized by scanning electron microscopy, energy dispersive spectrometry and X-ray diffraction, and the bacteriostatic effect of the coating onEscherichia coliand Staphylococcus aureus was determined by the film method. @* Results@#Energy dispersive spectrometry showed that Cu was introduced onto the surface of the MHL-Cu, MHM-Cu, and MHH-Cu groups, and the atomic ratios of copper in each group were （0.68 ± 0.04）%,（1.17 ± 0.06）%, and （1.64 ± 0.03）%. The difference between groups was statistically significant (P< 0.01). Scanning electron microscopy showed a crater-like porous structure on the surface of the MAO group, and the MHL-Cu, MHM-Cu, MHH-Cu, MH-Nb, MH-Cu/Nb groups maintained micropore morphology. The roughness increased with increasing Cu2+ concentration, in which the MH-Nb and MH-Cu/Nb groups showed gully like structures simultaneously. X-ray diffraction showed that the coating of the MAO group was mainly composed of titanium and anatase phase TiO2, and the coatings of the MHL-Cu, MHM-Cu, MHH-Cu, MH-Nb, MH-Cu/Nb groups were mainly composed of anatase and rutile phase TiO2. Compared with the MAO group, Escherichia coli and Staphylococcus aureus in the MHH-Cu, MH-Nb, MH-Cu/Nb groups decreased to varying degrees, with significant differences (P< 0.001); compared with the MH-Cu/Nb group, the colony number difference had statistical significance (P> 0.05)@*Conclusion@#The rough, porous coating containing copper and niobium prepared by the microarc oxidation-microwave hydrothermal two-step method can effectively inhibit the growth ofEscherichia coli and Staphylococcus aureus.
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Objective@#To investigate the antibacterial property and biological activity of Ti dental implant with antimicrobial peptide Pac-525 coatings, and to study the effect of peptide Pac-525 coatings on Porphyromonas gingivalis's antibacterial performance and osteoblast proliferation and adhesion.@*Methods@#After ultrasonic micro arc oxidation, alkali treatment and silane treatment, forty-five pure titanium specimens were exposed to antibacterial peptide Pac-525 in different concentration (0.25, 0.50, 0.75 g/L). The titanium specimens in the control group were only treated with ultrasonic micro arc oxidation, alkali treatment and silane treatment. The morphologies of coatings were observed by scanning electron microscope (SEM), and the element changes were detected by energy spectrum analyzer. Orange acridine-ethidium bromide double staining was used to detect the average percentage of live bacteria and biofilm thickness, after the specimens in each group and Porphyromonas gingivalis were co-cultured for 72 hours. Cell counting Kit-8 method and immunofluorescence staining were used to test the proliferation of osteoblasts, the number and growth morphologies of adherent cells, respectively.@*Results@#SEM and energy spectrum analysis showed that the Pac-525 particles loaded on the surface of the coating, and the C and N elements in the Pac-525 coating group were significantly more than those in the control group. The average percentage of living bacteria in the control group, 0.25, 0.50 and 0.75 g/L antimicrobial peptides were 0.58%, 0.45%, 0.34% and 0.28%, respectively, and the difference between each group was statistically significant (P<0.05). The biofilm thickness of Porphyromonas gingivalis in 0.50 and 0.75 g/L antibacterial peptide group were (98.3±1.2) and (94.5±2.5) μm respectively, which were significantly less than those in control group and 0.25 g/L antibacterial peptide group [(117.6±1.5) and (118.0±1.3) μm] (P<0.05), respectively. The number of bone cell adhesion and proliferation of all antimicrobial peptides were significantly greater than those in the control group (P<0.05), and the cells stretched better.@*Conclusions@#The antibacterial peptide coating of titanium implants could inhibit the formation of bacterial biofilm. It had good antibacterial properties and could promote the adhesion and proliferation of osteoblasts.
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Objective: To study the attachment, proliferation and ALP activity of osteoblasts on Ti-24Nb-4Zr-7.9Sn(TNZS) alloy surface treated by microarc oxidation (MAO). Methods: The surface roughness and energy of TNZS before and after MAO treated was examined by physicochemical methods, and pure titanium used as control. The primary cultured osteoblasts separated from calvarium of fetal rats were cultured and the third passage osteoblasts were seeded on 3 different surfaces of Ti, TNZS, MAO-TNZS discs. Biological assays were performed by MTT method. All data were statistically analyzed. Results: The surface energy and roughness of MAO-TNZS was higher than that of other groups; during the initial period of the cell adhesion on the materials, there were no differences among the three teams. But after 2 h, the cells adhesions on the surface of Mao-TNZS were higher than that on smooth surface and Ti (P
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Objective:To study the feasibility of microarc oxide treatment on the enhancement of titanium-ceramic bonding strength. Method:Titanium samples in the size of 25 mm?3 mm?0.5 mm were prepared with smooth surface(group 1),rough surface(group 2) and microacrc oxide treated surface(group 3). Nickel-chromium alloy samples in the same size were prepared (group 4). The surface of the samples was observed by scanning electron microscope(SEM) and dispersive spectrometry analysis. Then, the samples were bonded to porcelain. The bonding interface was observed by SEM. The bonding strength of the samples was measured by a three-point bending test according to ISO 9693.Results:Microarc oxide treated surface was rough and porous. The interface of microarc oxide treated surface bonded to porcelain was compact. The bonding strength(MPa) of the samples of group 1,2,3 and 4 to porcelain was 30.79?1.3,36.12?3.03,45.84?3.15 and 48.35?3.06 respectively(group 3 vs group 1 or 2 P0.05). Conclusion:The microarc oxide treatment on titanium can increase the titanium-ceramic bond strength.
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As a new surface technology, microarc oxidation can be applied to the ceramic coating with bioactivity on Ti alloy. With good biocompatibility, high bond strength and short healing period, the film is worth applying to clinical operation. In this paper such information of microarc oxidation is reviewed as its developing history, research progress and basic principle. The structure, properties and bioactivity of the ceramic coating are also introduced.