Effect of silver ion coating of fixed orthodontic retainers on the growth of oral pathogenic bacteria

Abstract

Titanium and stainless steel wires used for retainers in orthodontic procedures were coated with Ag ions and the effects of the coating on common oral pathogens and their pathogenicity were investigated. Two species of cariogenic and three species of periodontopathic bacteria were assessed. Biofilms of Streptococcus sobrinus and two VSC gases produced by P. gingivalis were also examined. Ag ioncoated wires showed marked antibacterial activities compared with uncoated wires; in most cases, the differences were statistically significant (p<0.05). All Ag ion-coated wires (Ti+ and SS+ wires) displayed more than 2-mm diameter bacteria growth-resistant zones around them in radial diffusion tests. Ag ion release was 0.043±0.005 ppm in 24 h that didn't show cytotoxicity. Thus, these results suggest that a simple Ag ion coating on pure titanium and stainless steel wires can restrict growth and pathogenic activities of oral pathogenic bacteria, even in the early stages of culture.

In vitro studies of nanosilver-doped titanium implants for oral and maxillofacial surgery

“…Consequently, they suggested that this was due to the decreased accumulation of silver ions in bacteria cells. 19 In the present study, Gramnegative bacteria were more susceptible to silver ions, which was in agreement with the results of other researchers. 50,51 The higher activity of SNPs against Gram-negative bacteria was …”

“…These results were in agreement with those from the study by Morita et al, where the concentration of 0.043 ppm sufficiently inhibited oral streptococci and P. gingivalis. 19 In this study, P. gingivalis, E. coli, and S. aureus appeared the most susceptible to SNPs. Oral streptococci were the least susceptible to nanosilver, with S. mutans being the most resistant, but the overall differences …”

“…12 Many studies regarding SNPs have been published, [13][14][15][16][17][18] although there has been little discussion on their application in oral implantology. 19 Most of the published works lack in comprehensive evaluation of the properties of the described materials, such as roughness, 15,17,20 wettability, 15,17,21,22 or biocompatibility. [14][15][16][17] Moreover, antibacterial activities in oral applications have been evaluated only in a few studies.…”

“…[14][15][16][17] Moreover, antibacterial activities in oral applications have been evaluated only in a few studies. 16,19 The aim of the present work was to assess the impact of SNPs on titanium surface properties and to verify the antimicrobial properties and the biocompatibility of such biomaterials in order to evaluate their potential for application in oral implantology.…”

“…However, they did not confirm their conclusions regarding biocompatibility in a cell culture assay. 16 The materials described by Morita et al released 0.04 ppm of silver ions after 24 hours of immersion in PBS, 19 although they did not observe any cytotoxic effects in the human gingival fibroblast cell line. On the other hand, the cells were cultured for 24 hours.…”