The aim of the study was to evaluate the periodontal conditions in patients treated more than 10 years ago for advanced periodontal disease and rehabilitated with cross-arch fixed partial dentures (FPDs). Of 50 randomly selected patients, 34 subjects carrying 43 FPDs agreed to participate in a clinical and radiographic follow-up examination. The FPDs were divided into three groups on the basis of prosthesis design (end abutments, unilateral cantilever, and bilateral cantilevers) and amount of supporting tissues at the time of bridge installation. Seventy per cent of the FPDs were found to be unchanged, whereas the rest had been modified due to various complications leading to extraction of one or more of the abutment teeth. Six FPDs (14%) had been partially replaced by FPDs anchored to osseointegrated dental implants. A total of 21 (8%) of the original 274 abutment teeth had been extracted. Longitudinal changes in the amount of periodontal support were minimal over the average of 15 years of follow-up. FPD design or initial amount of supporting tissues was found not to have significant influence on longitudinal changes in periodontal conditions. It was concluded that combined periodontal and prosthodontic treatment of patients with advanced loss of periodontal support may provide a high rate of long-term successful outcome, provided proper adequate periodontal and prosthetic treatment and maintenance care are given.