Background: Biofilm formation and microbial colonization on the surface of implant devices may cause dental caries and peri-implantitis. Therefore, various surface treatments have been developed to improve the antibacterial activity of titanium implant. Methods: Silver-loaded polydopamine coating was formed by immersing pure titanium in dopamine hydrochloride/HCl buffer solution for 24 h in 50 mL silver nitrate solutions with different concentrations for 30 min. Microbial growth inhibition and microbial growth curve analyses for bacterial solutions of Streptococcus mutans and Porphyromonas gingivalis incubated with the specimens were respectively conducted by counting the numbers of colonies on agar solid medium and by measuring absorbance using enzyme-linked immunosorbent assay reader. Results: Silver nanoparticles were uniformly distributed over the whole surface of the polydopamine and silver-coated titanium specimens. The numbers of microbial colonies for both bacteria cultured with surface-modified titanium were significantly lower than those cultured with uncoated titanium. When Streptococcus mutans and Porphyromonas gingivalis were cultured with surface-modified titanium, the lag phase of the growth curves for both bacteria was continually maintained, whereas the lag phase for Streptococcus mutans and Porphyromonas gingivalis changed to exponential phase after 9 and 15 h, respectively, when both bacteria were cultured with uncoated titanium. Conclusion: It was confirmed that the coating of polydopamine and silver on the surface of titanium effectively retards the microbial growth, which can cause the formation of biofilm and pathogenesis of gum disease in the mouth.

中文翻译：

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聚多巴胺和银表面改性增强钛的抗菌活性用于牙种植体应用

背景：种植体表面的生物膜形成和微生物定植可能导致龋齿和种植体周围炎。因此，人们开发了各种表面处理来提高钛种植体的抗菌活性。方法：将纯钛在盐酸多巴胺/HCl缓冲溶液中浸泡24 h，在50 mL不同浓度的硝酸银溶液中浸泡30 min，形成载银聚多巴胺涂层。通过计数琼脂固体培养基上的菌落数和使用酶联免疫吸附测定读数器测量吸光度，分别对与标本一起培养的变形链球菌和牙龈卟啉单胞菌的细菌溶液进行微生物生长抑制和微生物生长曲线分析。结果：银纳米粒子均匀地分布在聚多巴胺和镀银钛样品的整个表面上。用表面改性钛培养的两种细菌的​​微生物菌落数量明显低于用未涂层钛培养的细菌。当用表面修饰的钛培养变形链球菌和牙龈卟啉单胞菌时，两种细菌的​​生长曲线的滞后期持续保持，而变形链球菌和牙龈卟啉单胞菌的滞后期分别在 9 和 15 小时后变为指数期，当两种细菌都用未涂层的钛培养时。结论：证实钛表面的聚多巴胺和银涂层能有效地延缓微生物的生长，