1. Division of Endodontics, Department of Oral Biological and Medical Sciences, Faculty of DentistryUniversity of British ColumbiaVancouverBritish ColumbiaCanada
2. Department of Conservative Dentistry & Endodontics, Guanghua School of Stomatology, Guangdong Province Key Laboratory of StomatologySun Yat‐Sen University GuangzhouGuangzhouChina
3. Department of StomatologyAffiliated Hospital of Jining Medical UniversityJiningChina