Regarding the biofilm reduction assay, C. canephora extract of
Group 1 showed a low biofilm viability reduction (6.6%) at
90 mg/mL (against 20.6% by chlorhexidine), while C. arabica did
not show reduction at tested concentrations. The low reduction
of mature biofilm when compared to the inhibition of biofilm formation
was expected, since in a biofilm, bacteria are invariably less
susceptible to antimicrobial agents than their planktonic counterparts
(Wilson, 1996). Nonetheless, the inhibition of early biofilm
formation is more important than the reduction of mature biofilm
because once the formation of biofilm is inhibited, mature biofilm
existence may be prevented.