Many years ago, periodontal regenerative treatment has been done in Periodontics and Oral Medicine Clinic, Faculty of Dentistry, Mahidol University, Bangkok, Thailand. However, there is still lacking of study about long-term result of periodontal regenerative treatment of intrabony defects.

Beside, in the present, some materials for periodontal regenerative treatment are still expensive. Periodontists and patients have to plan together based on not only rationale of treatment but also cost and effectiveness. Thus the long-term result of treatment could be useful for the decision making.

Inclusion Criteria:

• Patients who received regenerative therapy of the intrabony defects
• Patients who had the record of re-evaluation at 1 year post-surgery

Exclusion Criteria:

• Patients who received regenerative therapy involving the furcation area
• Patients who received non-periodontal regenerative therapy
• Patients who received endodontic regeneration
• Patients who had an incomplete periodontal data recording

The patients who received regenerative periodontal therapy of the intrabony defects by post-graduate students at the Periodontics and Oral Medicine Clinic, Faculty of Dentistry, Mahidol University, Thailand and were placed in the Recall Patient Bank from 2000 to 2014.