The aim of this study was to analyze the effect of treatment with chlorhexidine digluconate (CHX DG) on the adhesion of oral bacteria to nickel-titanium and steel alloys which are the elements of orthodontic appliances . The study included treatment with three CHX DG-based solutions with an equal content of the active substance of 0.12% (Perio Plus®, Curasept® and CHX DG solution) on four bacteria; S. mutans, S. oralis, V. parvula and A. actinomycetemcomitans. The adhesive effect on orthodontic wires was registered after 24 hours for S. oralis and after 72 hours for other bacteria. The minimum bactericidal concentration of the solution for each bacteria was determined by the dilution method for testing the antibacterial activity. Saliva pre-treated orthodontic wire arches were exposed to minimal concentrations of the solution and bacteria. Commercially available preparations, especially Perio Plus®, showed a better effect on inhibiting the adhesion of all bacteria to both alloys versus a solution of pure CHX DG (p <0.05). A. actinomycetemcomitans was most inhibited in adhesion by CHX DG solution on all bacteria. On SS the inhibition of adherence was greater for streptococci and on NiTi for A. actinomycetemcomitans. Inhibition of V. parvula was treatment-dependent. In conclusion, inhibition of bacterial adhesion is dependent on CHX DG solutions, alloys and bacteria. CHX DG is effective in inhibiting bacterial adhesion to orthodontic elements and is recommended for chemical control of biofilm during orthodontic therapy with fixed appliances.