1Rubber dam isolation techniqueWANG Si-qi, CONG Xin-yu, XUE MingSYMPOSIUM257-2602Fracture resistance of the nickel-titanium instrumentsWANG Die, LI Jing, XUE MingSYMPOSIUM261-2643Calcium hydroxide paste and control of root canal infec-tionLI Jing, WANG Die, XUE MingSYMPOSIUM265-2684Strategy for hypercementosis and associated root canal infectionCONG Xin-yu, WANG Si-qi, XUE MingSYMPOSIUM269-2725Morphological recognition of the permanent mandibular first molar and its clinical significanceWANG Quan-yu, BI Wan-ting, ZOU Yun, XUE MingSYMPOSIUM273-2766Preparation of glide path and its clinical significance in root canal therapyLU Yu-kang, ZHANG Xiao-qin, ZHENG Zhi-guoSYMPOSIUM277-2817Treatment strategy for infected root canals bacterial bio-filmsWU Kuai-feng, ZHAO Xin-yu, DU YiSYMPOSIUM282-2868Preliminary study of the vestibular incision subperiosteal tunnel access combined with subepithelial connective tissue graft in the treatment of Miller class Ⅲ gingival recession:a case reportSUN Fei, WEI Ning, HU Wen-jie, WEI Yi-pingCOLUMN OF PERIODONTAL PLASTIC SURGERY TO IMPROVE THE AESTHETIC EFFECT OF NATURAL TEETH287-2929Preliminary exploration of simultaneous esthetic crown lengthening and subepithelial connective tissue graft combined with crown restorations for improving pink-white esthetics:a case reportWEI Ning, HU Wen-jie, LYU Long-wei, WEI Yi-pingCOLUMN OF PERIODONTAL PLASTIC SURGERY TO IMPROVE THE AESTHETIC EFFECT OF NATURAL TEETH293-29910Study on the apical sealing ability of three root canal sealers in vitroLYU Ao, LIN Xiao-xin, GUO Xiao-li, LIU Yi-qing, DU YiORIGINAL CONTRIBUTION300-30311An in vitro study of the centering ability of three nickel-titanium rotary instruments for root canal preparationWANG Tian-qi, LI Jia-you, XU Jia-ning, BAI Zhuo-ping, SU Guan-yu, XUE MingORIGINAL CONTRIBUTION304-30812Preparation and performance evaluation of a new-type computer numerical control cutting resin material for complete denture baseYAN Yue-qi, ZHAI Zi-di, LIU Jin-yu, SUN Jian, QIAN ChaoORIGINAL CONTRIBUTION309-31413Cone beam CT study of safe location of mesio-distal insertion of microimplants in palatine area of maxillary posterior areaLI Xing-han, XU Jia-lin, YANG Ying, DONG Yin-juan, LIU Shan-shan, ZHAO Li-hua, ZHANG Xiao-dongORIGINAL CONTRIBUTION315-31914Comparison of periodontal endoscope and cone beam CT in the diagnosis of vertical root fractureHE Zhi-fang, LI Yao, LI Xu-jian, LIU Zhi-fang, YANG Na-na, QI Jian-huaORIGINAL CONTRIBUTION320-32415Clinical evaluation of concentrated growth factors combined with minimally invasive surgical technique in the treatment of vertical bone defect of periodontitisCHEN Yu, DA Hai-qin, CHEN Ying, ZHOU Zhan-hao, WANG MianORIGINAL CONTRIBUTION325-32916Preparation of berberine hydrochloride root canal disinfection paste and evaluation of its antibacterial effects and cytotoxicity in vitroSHAO Yan-yan, TENG Hai-ying, ZHAI Yuan-kunORIGINAL CONTRIBUTION330-33617Preliminary study on the mechanism of histone demethylase UTX in fetal mice cleft palate induced by 2,3,7,8-tetrachlorodibenzo-p-dioxinZHANG Wei, ZHANG Zhi-xin, WANG ZhuoORIGINAL CONTRIBUTION337-34018Clinical study of 30 cases of the fracture of high-speed handpiece bur during minimally invasive extraction of impacted mandibular third molarLI Ze-xi, ZHENG Kai, WEI Chao, LI Yuan, WENG Zhi-jie, XIAO CanORIGINAL CONTRIBUTION341-34419Application of Simodont virtual simulation system in standardized training of stomatological residentsCHEN Min-min, XU Li, YANG An-wen, PENG Jiao, XIE Xiao-liCOLUMN OF STOMATOLOGY EDUCATION AND RESEARCH345-348,35220Evaluation of application effect of team-based learning combined with flipped classroom teaching mode in the teaching of debridement and suture of oral and maxillofacial regionLI Guo, WANG HangCOLUMN OF STOMATOLOGY EDUCATION AND RESEARCH349-352 