Temporal dynamics of adhesion of oral bacteria to orthodontic appliances

Abstract

Adhesion of the most common dental biofilm bacteria to alloys used in orthodontics in relation to surface characteristics was analyzed. Streptococcus mutans (S. mutans), Streptococcus oralis (S. oralis), Veillonella parvula (V. parvula), and Aggregatibacter actinomycetemcomitans (A. actynomicetemcomitans) were incubated for 4 h with nickel-titanium (NiTi) and stainless-steel (SS) wires. The surface roughness and free energy of the alloys, as well as the hydrophobicity of the alloys and bacteria, were assessed. NiTi had higher surface free energy and rougher (p<0.001) and more hydrophilic surfaces than SS (p<0.001). The hydrophobic properties of the bacteria decreased in the following order: V. parvula>S. oralis>S. mutans>A. actynomicetemcomitans. Bacterial adhesion generally increased over time, though this pattern was influenced by the type of alloy and the bacteria present (p<0.001). In a multiple linear regression, the principal predictor of adhesion was bacterial hydrophobicity (p<0.001), followed by time (p<0.001); alloy surface characteristics had a low influence.

Effect of Chlorhexidine Digluconate on Oral Bacteria Adhesion to Surfaces of Orthodontic Appliance Alloys

“…After homogenisation, tenfold dilutions were made on the microtiter plates, and after planting on the substrate, the bacteria were incubated under anaerobic conditions or with a candle. After 24 h, S. oralis was counted, and after 72 h, A. actinomycetemcomitans, S. mutans, and V. parvula were counted [22][23][24].…”