Abstract
The purpose of this study was to investigate the effect of Ag(NH3)2F on cariogenic Streptococcusmutans. In the first experiment, Ag(NH3)2F solution was applied on artificially produced 'white spot' of enamel samples. Adherence and growth of S. mutans strain Kl-R (serotype g) on these sample surfaces were observed by means of scanning electron microscopy. SnF2 and NaF solutions were also emp loyed to compare them with Ag(NH3)2F. In the second experiment, the effects of Ag(NH3)2F on the microflora in the plaque of interproximal surfaces of both permanent and primary molars were studied. Plaque samples were obtained before and after application of Ag(NH3)2F from interproximal surfaces and changes of the proportion of S. mutans were evaluated. The following results were obtained: 1) Adherence and growth of S. mutans cells on the enamel surfaces were markedly inhibited by Ag(NH3)2F treatment as compared with SnF2 or NaF.2) Immediately after the application of Ag(NH3)2F, microorganisms including S. mutans in the interproximal plaque were found to be almost completely eliminated.3) A significant reduction of the proportion of S. mutans by a single application of Ag(NH3)2F was observed after 7 days and this effect seemed to continue for over 4 weeks. These results suggested that Ag(NH3)2F reveals a marked antibacterial capability against interproximal microorganisms, especially S. mutans and should be effective for control of dental caries development.
