Figure 2.

Persistent effect of blue-light exposure on multispecies biofilm. Multispecies biofilm was exposed to blue light and compared with non-exposed biofilm. The biofilm was further incubated for an additional 6 h after exposure. P. gingivalis (pg) or F. nucleatum (fn) were stained with FITC. All bacteria were stained with the PI marker for dead bacteria. (a) – Percentage of total live and dead bacteria in exposed vs. non-exposed biofilm. (b) – Breakdown of the percentage of viable pathogenic bacteria (pg and fn) in exposed vs. non-exposed biofilm. (c) – Mean percentages of viable and nonviable pg or fn in exposed vs. non-exposed biofilm. The results are expressed as the mean ± SD. * and ^# indicate a significant difference from the other groups (live or dead).