1. Department of Periodontology, Periodontal‐Implant Clinical Research Institute Kyung Hee University, School of Dentistry Seoul Republic of Korea
2. Clinic of Reconstructive Dentistry, Center of Dental Medicine University of Zurich Zurich Switzerland
3. Department of Periodontology, Research Institute for Periodontal Regeneration Yonsei University College of Dentistry Seoul Republic of Korea