Potential of salivary proteins to reduce oral bacterial colonization on titanium implant surfaces

•Ti implant surfaces allow the adsorption of salivary proteins.•Protein adsorption is less sensitive to physico-chemical Ti surface features.•Histatin 5 prevent the adhesion of P. gingivalis on Ti implant surfaces.•α-Amylase decrease the colonization of S. gordonii and F. nucleatum on titanium. This study aims to test the potential of histatin 5, cystatin S and α-amylase to reduce the colonization of three important oral species; Streptococcus gordonii, Fusobacterium nucleatum and Porphyromonas gingivalis on two titanium (Ti) implant surfaces with different roughness and wettability. Pre-treatment (TiPT) and sandblasted and acid-etched (TiSLA) Ti surfaces, were facilitated by the Institut Straumann. The Ti surfaces were coated for two hours with either each salivary protein and the levels of protein adsorption were quantified by ELISA. The pre-coated substrates were incubated during 24 h with each bacterial strain, then bacterial colonization was measured by the counting of colony forming units and by fluorescence microscopy. Results showed that histatin 5 had the highest adsorption on the Ti surfaces, regardless of their roughness and wettability. However, bacterial colonization of each strain was selectively influenced by the presence of the salivary proteins adsorbed on the Ti substrates. The surfaces coated with α-amylase, decreased the adhesion of S. gordonii and F. nucleatum, while the pre-incubation with histatin 5 significantly reduced the colonization of P. gingivalis. Our results showed that bacterial colonization of the three oral bacteria could be selectively reduced by salivary proteins like histatin 5, cystatin S or α-amylase.