This report concerns long-term (4 to 5 years) clinical evaluation of 22 resolved (complete bone closure) mandibular Class 2 furcation defects following coronally advanced flap procedures and citric acid root treatment with or without adjunctive implantation of freeze-dried, demineralized allogeneic bone. Sixteen buccal furcation sites in 12 patients were available for the follow-up evaluation. The furcation involvement was independently evaluated by a panel of three examiners, each using three furcation index systems. Oral hygiene standards, gingival health, pobing depth, clinical attachment level, gingival recession, tooth vitality, and detectable caries or root resorption were also recorded. Mean attachment level at the furcation sites was 5.8 ± 2.9 mm, compared to 4.5 ± 2.2 mm and 3.5 ± 1.3 mm over the prominence of the mesial and distal roots, respectively. The clinical examination further revealed that 12 out of 16 sites exhibited recurrent Class 2 furcation involvement. Of the 16 teeth examined, one had received endodontic treatment, while the rem aining 15 responded within the normal range to pulp testing. One tooth had developed caries in the furcation region. No teeth demonstrated periradicular pathology. The results of this study question the long-term stability of furcation bone regeneration following coronally advanced flap procedures.