1. Department of Periodontics and Oral Biology, School of Stomatology, Jinzhou Medical University, Jinzhou, Liaoning 121000, P.R. China
2. Department of Periodontics and Oral Biology, School of Stomatology, China Medical University, Shenyang, Liaoning 110002, P.R. China
3. Department of Pathogeny Biology, Jinzhou Medical University, Jinzhou, Liaoning 121000, P.R. China