摘要
目的:了解第一恒磨牙根尖区根管自然锥度的状态。方法:离体上颌第一磨牙40颗和下颌第一磨牙44颗,从根尖孔处每隔1 mm与根管走行方向垂直连续横切,立体显微镜下30倍放大测量主根尖孔和距根尖孔1、2、3mm处根管横断面颊舌向和近远中向的最大径及最小径,寻找根管的最狭窄部位,计算根尖3 mm区根管各层区段的锥度。结果:上、下第一磨牙根管最狭窄处47.5%～60.0%位于根尖孔,25.0%～42.5%位于距根尖孔1 mm处;根尖3 mm区域根管锥度主要呈瓶颈型,距根尖孔1～2 mm区段根管锥度最大且变异较大(0.07～0.35),在1 mm处形成最缩窄的颈环;根管最大径的锥度大于最小径的锥度。结论:第一磨牙根尖部根管的自然锥度主要呈瓶颈型,在距根尖孔1 mm处形成的颈环形态有利于定位根管治疗的操作止点,根尖区根管锥度变异较大,可能影响根管的清创质量。
Objective：To investigate the physical morphology of the root canal taper in human maxillary and mandibular permanent first molars.Methods： Forty maxillary and 44 mandibular extracted human permanent first molars were investigated.The roots were dissected transversely from their apical foramen vertical to the long axis of the root,and 1-mm-thick serial sections were made.The root apex side of each section was observed with a stereomicroscope at 30× magnification.The maximum and minimum canal diameters were measured at 0,1,2,and 3 mm from the apical foramen.The physical canal taper in the apical section was calculated.Results： 47.5%-60.0% of the narrowest diameter of root canals were present at the foramen,and 25.0%42.5% located at the level of 1 mm from apical foramen.Almost all physical configurations of root canals in 3 mm apical region showed a bottleneck-like taper.Canal dia-meters increased rapidly at 1-2 mm with the biggest taper,and the taper had a bigger variance（0.07-0.35）.The ring of shrunken bottleneck was formed at the level of 1 mm from apical foramen.The taper of canal in maximal diameter was larger than the one in minimal diameter.Conclusion： The physical morphology of bottleneck-like taper in apical canal was helpful to locate the canal apical stop in root canal treatment.
出处
《北京大学学报（医学版）》
CAS
CSCD
北大核心
2010年第1期20-23,共4页
Journal of Peking University:Health Sciences
基金
卫生部部属(管)医院临床学科重点项目([2007]353-46)
首都医学发展基金(2007-1006)资助~~
关键词
磨牙
根尖狭窄
牙髓腔
Molar
Apical constriction
Dental pulp cavity
