The cantilever fixed partial denture has often been considered as a poor prosthetic design by dentists, because of the frequently happened failure caused by biological and technical complications. We provides a 12-years long-term follow up case of the abutment teeth of the lower unilateral posterior cantilever fixed partial denture. In the observation period, we found periodontal ligament widening and alveolar bone undermining resorption of the distal abutment tooth. After removal of the cantilever extension, the recovery of the alveolar bone has been observed radiographically.