1. Department of OrthodonticsThe First Affiliated Hospital of Zhengzhou University Zhengzhou 450000 China
2. Laboratory of Biomimetic NanomaterialsDepartment of OrthodonticsPeking University School and Hospital of StomatologyNational Engineering Laboratory for Digital and Material Technology of StomatologyBeijing Key Laboratory of Digital Stomatology Beijing 100081 China
3. Beijing Key Laboratory of Biogas Upgrading UtilizationChina University of Petroleum (Beijing) Beijing 102249 China
4. Central LaboratoryPeking University School and Hospital of Stomatology Beijing 100081 China
5. Fourth DivisionPeking University Hospital of Stomatology Beijing 100025 China