[The effect of fluorides on the surface structure of titanium implants]

The high fluoride concentration and the acidic pH in tooth-paste used to prevent caries may modify the surface structure of implants made of titanium. Oxidative agents thicken and condense the titanium-dioxid layer on the surface of titanium and improve its stability against corrosion effects, while reductive agents like fluoride may have the opposite effect and attack this layer. The aim of the present work was to study the effects of fluoride containing toothpaste and gel on the titanium dioxid layer of titanium. The surfaces of the titanium (commercial pure grade I.) discs were treated with toothpaste and gel containing 0.125 % and 1.25 % fluoride, respectively. The changes in the surface structure were analyzed by atomic force microscope (AFM) and X-ray photoelectron spectroscopy (XPS). Our results demonstrated that fluoride strongly binds to the titanium surface and modifies its structure in case of fluoride containing gels.