上海交通大学学报（医学版）2025，Vol.45Issue(5)：597-604,8.DOI:10.3969/j.issn.1674-8115.2025.05.008
下颌第一磨牙根管直径和锥度的锥形束CT测量分析
Cone-beam CT measurement of root canal diameter and taper for mandibular first molar
摘要
Abstract
Objective·To analyze the root canal diameter and taper of mandibular first molars using cone-beam CT(CBCT),investigate age-related changes in these parameters,and propose optimized clinical protocols for root canal preparation.Methods·From October 2022 to October 2023,CBCT images of 240 healthy mandibular first molars(120 three-canal type cases and 120 four-canal type cases)were collected from patients aged 20‒59 years at the Stomatology Center,Haikou Affiliated Hospital of Central South University Xiangya School of Medicine.The three-canal type and the four-canal type samples were respectively divided into four age groups(20‒29,30‒39,40‒49,and 50‒59 years),with 30 cases in each group.Root canal length was measured,and buccolingual and mesiodistal diameters were recorded at four levels(coronal,middle,apical,and foramen).The tapers of the coronal 1/3,middle 1/3,and apical 1/3 segments were calculated in both buccolingual and mesiodistal directions.Differences among the age groups were compared.Results·The buccolingual diameters of all root canals exceeded the corresponding mesiodistal diameters.At several levels of most root canals,the diameters in the<50-year-old groups were significantly larger than those in the 50‒59-year-old group(P<0.05).The buccolingual tapers exceeded the corresponding mesiodistal tapers in all root canals of mandibular first molars.The mean mesiodistal tapers in different age groups ranged from 0.07 to 0.34 in the coronal 1/3 segment,0.03 to 0.09 in the middle 1/3 segment,and 0.05 to 0.11 in the apical 1/3 segment.At several levels of most root canals,the tapers in the<50-year-old groups were significantly larger than those in the 50‒59-year-old group(P<0.05).Conclusion·Mandibular first molars exhibit age-related narrowing of root canal diameter and reduced taper in individuals aged≥50 years.For initial apical file selection,#15 files are recommended for the distal canals in the three-canal type,while#10 files are advised for all other canals in the three-canal type and all canals in the four-canal type.For patients aged 50 years or older,the files for the distal canals in the three-canal type can be adjusted to#10,and the files for the mesiobuccal and distallingual canals in the four-canal type to#8.Regarding preparation taper,a 0.08-taper orifice opener is recommended for the coronal 1/3 segment.During mid-lower segment preparation,0.04-taper master apical files are suggested for the mesiobuccal and mesiolingual canals in the three-canal type and the mesiolingual and distallingual canals in the four-canal type,0.06-taper files for the distal canals in the three-canal type and the mesiobuccal canals in the four-canal type,and 0.08-taper files for the distobuccal canals in the four-canal type.Root canal obturation is recommended to be performed using vertical compaction with large-taper gutta-percha cones combined with bioceramic sealer.关键词
下颌第一磨牙/根管直径/根管锥度/锥形束CT/增龄性改变/根管治疗/根管预备/根管充填Key words
mandibular first molar/root canal diameter/root canal taper/cone-beam CT(CBCT)/age-related change/root canal therapy/root canal preparation/root canal filling分类
医药卫生引用本文复制引用
李文妙,邢莉,潘英瑜,黄滢,杨国访,刘德达..下颌第一磨牙根管直径和锥度的锥形束CT测量分析[J].上海交通大学学报（医学版）,2025,45(5):597-604,8.基金项目
海南省卫生健康行业科研项目(22A200122). Scientific Research Project of Health Industry in Hainan Province,China(22A200122). （22A200122）
