1 Department of Periodontology, The Affiliated Hospital of Qingdao University, Qingdao, China.
2 Laboratory of Oral Microbiota and Systemic Diseases, Shanghai Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, China.
3 Department of Periodontology, The Affiliated Hospital of Qingdao University, Qingdao, China - wxuan6343@163.com.