1. The State Key Laboratory Breeding Base of Basic Science of Stomatology (Hubei-MOST) & Key Laboratory of Oral Biomedicine Ministry of Education; School and Hospital of Stomatology, Wuhan University; Wuhan Hubei 430079 People's Republic of China
2. Department of Dental Implantology; School and Hospital of Stomatology, Wuhan University; Wuhan Hubei 430079 People's Republic of China
3. Department of Periodontology; University of Bern; Bern Switzerland