【作者】 潘莉； 章润贞； 李颂；

【Author】 LIPan,ZHANGRunzheng,LI Song(College of Stomatology.Anhui Medical University,Hefei 230032,China)

【机构】 安徽医科大学附属口腔医院；

【摘要】 目的:获取下颌第二前磨牙根管的初始锥度,揭示根管原始锥度特征,并探讨其增龄性变化。方法:收集有年龄标记、牙体完整的人离体下颌第二前磨牙33颗,按年龄分为青少年组,中年组和老年组。采用显微CT对标本从根尖向冠方进行断层扫描。通过3ddoctor软件在扫描图上测量根管冠、中和尖1/3段颊舌向和近远中向直径,计算这三个水平段颊舌向和近远中向根管锥度。结果:青年组根管近远中向锥度由根冠至根尖分别平均为0.06,0.08,0.07,颊舌向分别为:0.32,0.21,0.25。颊舌向根管锥度在不同水平段有统计学差异(p<0.05)而近远中向根管锥度在不同水平段无统计学差异(p>0.05)。结论:单根管下颌第二前磨牙青少年组根管颊舌方向锥度变化明显,最小的部分在根中1/3。近远中方向锥度较颊舌方向小但根管上下差别不大,呈均匀连续的变化。更多还原

【Abstract】 OBJECTIVE:The purpose of this study was to determine the root canal initial taper of mandibular second premolars by using Micro-computed tornography(MCT),reveal the characteristics of initial taper and investigate the influence of age on the taper of the canal.METHODS:.33 extracted,single-rooted,untreated human root canal of mandibular second premolars were selected.These premolars were grouped according to age:adolescents,adults and elderly The teeth were embedded in resin.The resins were scanned using MCT at a resolution of 10μm.Choose the photographs at each level of 1mm perpendicular to the long axis of the tooth.The canal diameters of each photograph were measured with a imaging software through bucco-lingual(BL) and mesio-distal(MD) direction and cervical、middle and apical third of the canals.Finally the taper were calculated and analyzed.RESULTS:the average taper of cervical,middle,and apical third of adolescents’root canals were:0.06、0.08、0.07 mesio-distally and 0.32、0.21、0.25 bucco-lingually.The difference was not observed among three level on MD direction about the canal taper by t-test(P<0.05),but there were difference among three level on BL direction about the canal taper by t-test(P>0.05).CONCLUSION:The single root canal initial taper of mandibular second premolars change obviously on bucco-lingual direction when they were adolescents,the minimum segment was at middle third of the canals.In all root segments the BL taper change continuous and less than the MD taper.更多还原