1. Department of Endodontics, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, Beijing, China
2. Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Beijing Stomatological Hospital, School of Stomatology, Capital Medical University, Beijing, China
3. Department of Pediatric Dentistry, Tianjin Stomatology Hospital, Tianjin Medical University, Tianjin, China