Methods: An experimental resin-based restorative material representing a common formulation for resin-based composite was prepared (ST) and used as a standard. ST was modified by replacing only small parts of the filler (4%) with a methacrylate based delivery system loaded with triclosan as an anti-bacterial agent resulting in the test material AB. N=6 disc-shaped samples per group (diameter 10±0.1mm, thickness 1±0.1mm) were prepared, polymerized (40s/side), water-stored (37°C, 21d), disinfected and polished (1min, fine/superfine polishing discs). Afterwards samples were stored in human saliva (250μl, 2h, 37°C), washed and incubated with an overnight-culture of A. naeslundi, A. viscosus, S. mitis, S. oralis and S. sanguis (350µl, 8h, 37°C respectively 24h, 37°C). Vital fluorescence was performed on four randomly chosen sites per sample by using LIVE/DEAD BacLight bacterial viability Kit (Molecular Probes, Eugene, OR, USA). Quantification of vital (fluorescent green) and avital (fluorescent red) bacteria was calculated by counting pixel per colour. A t-test for unpaired samples was performed (SPSS).
Results: A significant reduction (p<0.05) of vital bacteria except for S. mitis and an increase of avital bacteria could be found after 8h on AB. After 24h this effect could be shown for all tested bacteria except for S.sanguis. The total amount of bacteria was mostly not affected.
Conclusion: Using new delivery systems loaded with an antibacterial agent might allow changing the initial adhesion of bacteria onto resin-based restorative materials. It could be demonstrated that the ratio of vital and avital adhering bacteria could be changed.
This research was supported by Deutsche Forschungsgemeinschaft (RU825/3-1).