For the fixation of mandibular fractures, at the Department of Oral Surgery and Dentistry at Semmelweis University, anodically and thermically treated TiO2/Ti osteosynthesis plates are used. The corrosion studies were performed in a generally-applied 3-electrode electrochemical measurement cell, with a calomel electrode as reference electrode, and a Pt net as conducting electrode. The cyclic voltammetric measurements demonstrated that the pore-free surface TiO2 layer forms a highly protective barrier on the surface of Ti. The electrochemical impedance spectrum reflected a decrease in inhomogeneity of the sample because of a decrease in the number of pinholes. Such a change is indicative of passivation. The reported techniques appear to comprise a reliable method of study for an evaluation of the long-term corrosion behaviour of implants.