1. Department of Stomatology, The General Hospital of Western Theater Command PLA, Chengdu, China
2. Maine Health Institute for Research, Scarborough, ME, USA
3. State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases & Department of Operative Dentistry and Endodontic, West China Hospital of Stomatology, Sichuan University, Chengdu, China
4. State Key Laboratory of Oral Diseases & National Center for Stomatology & National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China