Figure 3

Minimal inhibitory concentration (MIC) of DMAHDM, DMADDM and CHX dissolved in medium against planktonic S. gordonii (mean ± SD; n = 3). Twenty passages were tested, and each subsequent passage used the surviving bacteria from the previous passage as inoculum, in order to examine potential drug resistance. A two-fold increase in MIC was found for S. gordonii against DMADDM or CHX, indicating drug resistance. However, no changes in MIC occurred for DMAHDM, indicating no drug resistance.