Silver release from silver-containing hydroxyapatite coatings

Silver release plays an important role in the long-term anti-bacterial effect. In this paper, silver-containing hydroxyapatite coatings were prepared by coprecipitation or plasma spraying (denoted as T1 and T2 respectively). The behavior of silver release from the composite coatings in buffering fluid (BF) or simulated body fluid (SBF) was monitored, and then the factors affecting the silver release in fluid were studied. The results show that the two coatings can slowly release nano silver particle and Ag+ ions in BF and SBF solutions, which presumably made the coatings exhibit a good anti-bacterial effect. Immersion in SBF was applied to test the bioactivity of T1 and T2 coatings. The results display that the rate of release of silver particles was higher for T1 coatings compared to T2 coatings. This suggests that the bioactivity of T1 was potentially higher than that of T2, and that the phase composition and surface morphology of the coatings may affect their bioactive properties.