M. BEHR*, A. LEIBROCK, P. RAMMELSBERG, G. HANDEL, W. GERNET If a tooth is missing on a caries free dentition due to trauma or hereditary absence, the tooth can be replaced by dental implants or adhesive-fixed partial prosthodontics. The aim of the study was to compare the rate of failure and complication of adhesive-fixed partial prosthodontics to those of the suprastructure of dental implants from the IMZ (Friatec) and ITI Bonefit (Straumann) system. 181 adhesive-fixed partial prosthodontics and 48 implant suprastructures (crowns and bridges) were inserted in a 9 -years longitudinal study under controlled conditions. The rate of complications such as failure of partial or full veneers, fracture of metal base, screw-loosening, failures of the abutments and the adhesive metal-composite compound were investigated. The influence of location (anterior/posterior), gap width (number of replaced teeth), preparation technique (retentive, less retentive) and the influence of the abutment system of the dental implants were investigated using the Cox proportional-hazard model. The variables location and gap width were rejected as significant risk factors of adhesive-fixed prosthodontics in the Cox model. However, retentive tooth preparation of adhesive-fixed partial prosthodontics reduced the risk of failure significantly (p< 0.0001). Suprastructures made on IMZ implants had considerably more failures and complications than from the ITI system (p<0.05). There was no significant difference in the rate of complications and failures between the ITI system and adhesive fixed partial prothodontics, but by contrast, the IMZ system did show such differences. Conclusion: replacement of teeth missing as a result of trauma or hereditary absence shows the same success and complication rate using dental implants or adhesive-fixed partial prosthodontics.