1. Shandong Provincial Key Laboratory of Oral Tissue Regeneration, Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration, School and Hospital of Stomatology, Shandong University, Jinan, Shandong 250012, P. R. China
2. Liaocheng People’s Hospital, Medical College of Liaocheng University, Liaocheng 252000, P. R. China
3. College of Materials Science and Engineering of Liaocheng University, Liaocheng 252000, P. R. China
4. Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, P. R. China