BACKGROUND: The aim of this prospective 10-year study of partially edentulous subjects treated for generalized aggressive periodontitis and periodontally healthy subjects was a clinical, microbiologic, and radiographic comparison of teeth and implants and assessment of the implants' success rate. METHODS: Five subjects treated for generalized aggressive periodontitis (GAgP) and five periodontally healthy subjects who were orally rehabilitated with osseointegrated implants participated in the study. First, they were examined 2 to 4 weeks before extraction of the non-retainable teeth (baseline) and 3 weeks after insertion of the final abutments. All further examinations were performed during a 3-month recall schedule over a 10-year period. At every session, clinical parameters were recorded, and the composition of the subgingival microflora was determined. Radiographs were taken at baseline after insertion of the superstructure and 1, 3, 5, 8, and 10 years later. RESULTS: Throughout the follow-up period, the peri-implant gingival index of GAgP subjects was significantly higher than in periodontally healthy subjects. There was no difference in plaque index between teeth and implants or between the two groups. The peri-implant probing depths were comparable in the two groups and remained < or =4 mm throughout the follow-up. The probing depth was significantly higher around the teeth of the GAgP subjects compared to periodontally healthy subjects. Implants of GAgP subjects showed a significantly higher attachment loss (Ø 2.4 mm). The attachment level at teeth and implants of the periodontally healthy subjects and at teeth of the GAgP subjects was almost unchanged. Microbiologically, GAgP subjects had fewer cocci and more motile rods and filaments at teeth and implants than periodontally healthy subjects. GAgP subjects showed significantly more peri-implant bone loss in the first year (Ø 2.07 mm) and in the subsequent 9 years (total 1.3 mm). Bone loss at teeth also was significantly higher at baseline (Ø 26.39%) and in the following years (total 9.3%). Implant survival rates were 100% in periodontally healthy subjects versus 83.33% in GAgP subjects. CONCLUSIONS: This 10-year study showed that partially edentulous subjects treated for GAgP can be rehabilitated successfully with osseointegrated implants. However, the bone and attachment loss at the implants were higher than in periodontally healthy subjects.