An alternative implant material which has reached the clinic is titanium-zirconium alloy. It has been shown to have an increased rigidity in comparison with titanium and comparable biological characteristics but the documentation consists mainly of animal studies and short term clinical follow-up in the form of case-series. Since it has been demonstrated that the choice of implant material may influence osseointegration, it is necessary to evaluate the implants made of titanium-zirconium in a clinical controlled study with long-term follow-up in which the emphasis is put on the clinical outcome.