1. Department of Oral and Maxillofacial Surgery The Affiliated Hospital of Qingdao University No.1677 Wutaishan Road Qingdao 266003 China
2. School of Stomatology of Qingdao University Qingdao University Qingdao 266003 China
3. School of Materials Science and Engineering Shandong University of Science and Technology Qingdao Shandong 266590 China
4. State Key Laboratory of Mining Disaster Prevention and Control Co-founded by Shandong Province and the Ministry of Science and Technology Shandong University of Science and Technology Qingdao 266590 China
5. Department of Endodontics The Affiliated Hospital of Qingdao University Qingdao 266003 China
6. Department of Radiology The Affiliated Hospital of Qingdao University Qingdao China
7. Key Lab of Oral Clinical Medicine The Affiliated Hospital of Qingdao University Qingdao 266003 China