Fig 1.

Effect of NaF, ampicillin, and chlorhexidine treatment on the extent of biofilm detachment. Biofilm developed on PLS blocks was further treated with different concentrations of NaF, ampicillin, and chlorhexidine. The optical density at 550 nm (OD₅₅₀) of flowthrough with biofilm-detached cells at various time points after treatment was measured. Results are expressed as percentages compared to OD₅₅₀ measurements of untreated biofilms formed in parallel, which were considered 100% (0.50 after 1 h, 0.47 after 3 h, and 0.53 after 3 h). *, significant difference compared to control group (P < 0.05). (A) NaF at 1,000 μg/ml and 2,000 μg/ml inhibited biofilm detachment. (B) Ampicillin (AMP) at all concentrations tested significantly inhibited biofilm detachment (P < 0.05). (C) Chlorhexidine (CHX) at sub-MIC levels promoted biofilm detachment but otherwise inhibited detachment.