CLSM observation of <i>Porphyromonas gingivalis</i> biofilms formed in the presence of melatonin and ramelteon at sub-MIC concentrations.

<p>(A) CLSM images of <i>Porphyromonas gingivalis</i> biofilm formed in the presence of melatonin and ramelteon at sub-MIC concentrations. Biofilm-forming cells were stained using the Live/Dead Bacterial Viability Kit. Dead cells were stained red, whereas live bacteria were stained green. In the presence of 50 μg/mL or 25 μg/mL ramelteon, the areas of biofilm formation were narrower than that of vehicle controls. Bars = 50 μm. (B) Effects of melatonin and ramelteon on the thickness of <i>Porphyromonas gingivalis</i> biofilms. Data represent the mean ± SEM (<i>n</i> = 12) and differences between groups were assessed by ANOVA, **<i>P</i> < 0.01 versus vehicle control.