Antimicrobial effects of glass ionomer cements containing bioactive glass (S53P4) on oral micro-organisms in vitro.

The antimicrobial effects of two glass-ionomer cements (GICs), GC Fuji II and Fuji II LC, mixed with different amounts (0 wt%, 10 wt% and 30 wt% of the total powder weight) of bioactive glass (BAG), S53P4, on Streptococcus mutans and Candida albicans were studied in vitro. The growth inhibition was tested using agar diffusion. The materials were also studied in a liquid media. The effect of the material extracts on acid production was studied using cell suspensions. The antimicrobial activity of the materials was examined by incubating the cell suspensions with the material powder. In the agar diffusion test, only the GICs containing 30 wt% BAG inhibited the growth of S. mutans. When the materials were tested in culture medium, no inhibitory effects on S. mutans were detected. The only materials to inhibit acid production of S. mutans were the GIC extracts without added BAG. Furthermore, they also had antibacterial activity against S. mutans when tested as powders. We found very few effects of the tested materials on C. albicans. The only material with an antimicrobial effect on C. albicans was BAG when incubated in a suspension with C. albicans. This is the first time that this effect has been demonstrated for C. albicans. By adding BAG to GICs the structure of the material becomes more brittle than the structure of GICs without BAG. Thus, in addition to the composition of the tested materials, their structure may also have influenced the results. In summary, commercially available GICs and GIC disks containing 30 wt% of BAG exerted antibacterial effects on S. mutans. BAG exerted antimicrobial effects on both S. mutans and C. albicans.