The present clinical trial clarified that basic fibroblast growth factor-2 (FGF-2) can induce regeneration of periodontal tissue lost by progression of periodontitis and evaluated the safety of such induction.

Inclusion Criteria:

• diagnosed as 2- or 3-walled vertical intrabony defect >=3 mm deep from the top of the remaining alveolar bone
• with mobility of the tooth of degree 2 or less
• with width of attached gingiva appropriate for Guided Tissue Regeneration

Exclusion Criteria:

• concomitant administration of adrenal cortical steroid within 4 wks after the surgery
• administeration of calcium antagonist during the 4 weeks preceding administration of the investigational drug
• coexisting malignant tumour or history of the same
• coexisting diabetes (HbA1C >= 6.5%)
• an extremely poor nutritional condition (serum albumin concentration <2 g/dL)
• pregnancy or lactation