1. State Key Laboratory of Oral DiseasesNational Clinical Research Center for Oral DiseaseWest China Hospital of StomatologySichuan University Chengdu PR China
2. Department of Periodontics and Oral MedicineUniversity of Michigan School of Dentistry Ann Arbor MI
3. Department of Dental TechnologyWest China Hospital of StomatologySichuan University Chengdu PR China
4. Department of Reconstructive DentistryUniversity Center for Dental Medicine BaselUniversity of Basel Basel Switzerland