The lack of the periodontal ligaments around the implants results an ankylotic fixation. The mobility of the osseointegrated implants is only one tenth of the mobility of the natural teeth. To connect a natural tooth and an implant as abutments in a fixed restoration is a special problem in the dentistry. The aim of this study was to examine whether connecting of implants and natural teeth has any disadvantages for the abutment either implant or natural tooth. Furthermore we wanted to know if an overloading of the opposing tooth could occur because of the stiffness of the implant-bone connection. 21 partially edentulous patients, who were treated with implant supported bridges using the DenTi implant system which includes screw-shaped, commercially pure titanium implants, were examined. Plaque, calculus, gingival index, probing depth and bleeding on probing were recorded around the implants and the teeth. Mobility, sound on percussion were examined as well. In this study no disadvantageous effect of connecting teeth to implants as abutments by fixed partial dentures was found. There was no sign of a harmful effect of the implant to the opposing teeth either. The tooth-to-implant bridges function in their biological environment without affecting it adversely.