Adhesion and biofilm formation by periodontopathogenic bacteria on different commercial brackets.

To compare early bacterial adhesion and biofilm formation of common and uncommon periodontal pathogens on a variety of commercial brackets in vitro. In vitro adhesion and biofilm formation of 4 bacterial strains on 15 different commercial brackets, in standard culture mediums with and without addition of either serum or human saliva was evaluated by quantitative real time PCR after extraction of bacterial DNA. Materials significantly influenced bacterial adhesiveness in a species-specific way. Titanium and gold brackets constantly yielded the lowest values with all tested bacteria and in all tested conditions. Bracket materials and medium of growth significantly influenced biofilm formation. Materials and environmental conditions significantly influence biofilm formation by periodontal pathogens at the surface of brackets. Whenever possible brackets should be kept far from the gingival margin and if this is not possible, brackets made of gold, titanium, and ceramic should be preferentially used.