1. Department of Oral Geriatrics, Hospital of Stomatology, Jilin University, Changchun 130021, P. R. China
2. State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, P. R. China
3. Jilin Provincial Key Laboratory of Tooth Development and Bone Remodeling, Hospital of Stomatology, Jilin University, Changchun 130021, P. R. China
4. School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
5. Physical Science Department, MacEwan University, Edmonton, Alberta T5J 4S2, Canada