Adhesion of Aggregatibacter actinomycetemcomitans and Fusobacterium nucleatum on bioactive TiO2 surfaces

Background Bioactive TiO2 coatings have been found to enhance fibroblast adhesion and gingival attachment on the titanium surfaces, but no information is available whether the coatings also promote the adhesion of periodontal pathogens. Aim The purpose of this study was to investigate protein adsorption and the adhesion of Aggregatibacter actinomycetemcomitans (Aa) and Fusobacterium nucleatum (Fn) on bioactive TiO2 surfaces. Materials and methods Commercially pure titanium discs (diameter 11.0 mm, grade 2) were coated with sol-gel derived bioactive TiO2 coatings (MetAlive, Vivoxid, Turku, Finland) and preincubated in 1.5 ml PBS/diluted serum/diluted saliva at room temperature to mimic the clinical situation after implantation and to allow serum/saliva proteins to adhere on the substrates. Uncoated titanium discs were used as controls. Results SDS-PAGE revealed similar protein profiles on bioactive and control titanium substrates. No differences were noticed in Aa or Fn adhesion between bioactive and control titanium. However, serum and saliva conditioning diminished Aa adhesion on both surfaces (p<0.001). Conclusion It can be concluded that bioactive TiO2 coating does not promote adhesion of Aa and Fn.