The results obtained by many researchers indicate that bactericidal substances such as silver, ciprofloxacin and fluoroquinolone reduce the ability of microorganisms to colonize the surface of materials and tools, thus inhibiting biofilm formation . Gram-negative bacteria have greater biofilm formation ability because their outer cell membranes contain lipopolysaccharide (LPS), which facilitates cells adhesion to a surface and initiates processes associated with biofilm formation. Similar results are presented in this paper: Gram-negative E. coli formed more abundant biofilm on the test samples than Grampositive S. aureus