Institution: | 1. Department of Endodontics, School of Stomatology, Tianjin Medical University, , Tianjin, China;2. Department of Paediatrics, Yantai Stomatological Hospital, , Yantai, China;3. Department of Endodontics, Yantai Stomatological Hospital, , Yantai, China;4. Department of Stomatology, The First Affiliated Hospital of Henan University of TCM, , Henan, China |