Abstract
Conventional periodontal regenerative surgery has limited effect on tooth with severe periodontitis-related alveolar bone defects. This article reported a case of regenerative treatment in severe distal-bone defect of mandibular first molar. The treatment involved applying 3D printing, advanced/injectable platelet-rich fibrin, and guided tissue-regeneration technology. After the operation, the periodontal clinical index significantly improved and the alveolar bone was well reconstructed.