上颌第二前磨牙根管峡发生率和位置的研究

目的：研究离体单根的上颌第二前磨牙根尖1—6mm处根管形态及根管峡部的发生率和位置的情况。方法：收集离体上颌第二前磨牙60颗，自根尖开始，片切去除1mm牙根后，用美蓝染色根切面，在显微镜下观察并记录各横截面的根管数和峡部分布情况。在距根尖1～6mm区域内每隔1mm处重复以上操作。结果：上颌第二前磨牙双根管率是41．67％；根管峡部在距根尖4mm水平最高。结论：上颌第二前磨牙根管峡部在距根尖3—5mm区最高发；根尖1～6mm区域根管系统形态复杂。     

下颌第一前磨牙根管峡部的显微CT研究

目的:运用显微CT研究非单根管的下颌第一前磨牙根尖0～6 mm区域根管峡部出现的位置和发生率,为提高根管治疗和根尖外科手术的成功率提供解剖学依据。方法:从147颗下颌第一前磨牙中挑选出非单根管的40颗,用显微CT以15μm分辨率、30μm层厚扫描及软件三维重建,观察并记录根尖0～6 mm区域各横截面的峡部形态及分布情况,并对根管系统的解剖形态三维重建后,进行二维、三维图像分析。结果:非单根管的下颌第一前磨牙距根尖0～6 mm区域内根管峡部的发生率(%)由根方向冠方以每1 mm为间距依次为:6%、18.5%、78.6%、80%、79.2%、72.5%。结论:非单根管下颌第一前磨牙根管峡部在距根尖3～6 mm区域高发,其中距根尖3～4 mm区域发生率最高。     

上颌第一前磨牙根管峡部的解剖形态研究

目的 观察上颌第一前磨牙的根管分布、峡部形态和纵向走行变化,为根管治疗和根尖手术提供根管解剖形态的指导.方法 收集北京大学口腔医学院·口腔医院口腔颌面外科门诊拔除的上颌第一前磨牙118颗,进行横切片,体视显微镜下观察牙根全长的根管数目、峡部形态及Hsu和Kim分型.结果 72.0％(85/118)的牙根含双根管,有峡部者占69％(59/85);牙根在根冠1/3段的双根管占99％(84/85),独立双根管和含峡部者均占49％ (42/85),含峡部双根管在向根尖走行的过程中逐渐融合为单根管;全根长中根管峡部的横断面形态主要为Ⅳ和V型.结论 上颌第一前磨牙双根管间峡部主要存在于根中1/3,横断面形态与根管通联,根冠向根尖走行过程中渐融合为单根管;提示临床根管治疗中应以渗透性强的冲洗剂充分浸泡,加强对峡部的清理,提高疗效.     

上颌第一前磨牙根管峡区充填技术的实验研究

目的：体外研究配合或不配合使用超声冲洗的条件下连续波热牙胶充填技术和冷侧方加压充填技术对上颌第一前磨牙的根管及根管峡区的充填质量。方法：选择单牙根双根管的上颌第一前磨牙40颗,根管预备后随机分为4组：A组,侧方加压充填;B组,超声冲洗＋侧方加压充填;C组,连续波热牙胶加压充填;D组,超声冲洗＋连续波热牙胶加压充填。充填后拍摄X线片,记录根管类型和峡区发生情况。从根尖方向冠方水平片切牙根,间隔1mm,选择有根管峡区的横断面在体视显微镜下观察其充填质量并进行评分。结果：X线片和横断面上单牙根双根管的上颌第一前磨牙根管峡区的发生率分别为87.5%和90%。D组根管峡区充填质量优于其它3组（P〈0.05）,B组和C组之间无显著性差异,A组充填质量最差。结论：连续波热牙胶充填技术配合超声冲洗能显著提高对根管峡区的处理能力,值得临床推广应用。     

根管峡部的发生率及其临床意义

根管峡部是指同一牙根内两根管间,含有牙髓或者牙髓生成组织的一种窄形、带状结构[1]。Cambruzzi[2]和Vertucci等[3]曾阐述过两个根管之间的峡区这一解剖特征。顾永春等[4]指出根管峡为管间吻合的一种,相邻根管间有时存在狭窄的腔隙将两根管相通,在水平截面呈8字或字母C的腰部,     

上颌第一前磨牙根管及根管峡区再治疗的实验研究

目的：评估不同再治疗技术清理根管及峡区内根充物的效果。方法：30颗单牙根双根管的上颌第一前磨牙采用热牙胶连续波充填技术充填后分为3组去除根充物：A组,不锈钢器械（K锉和H锉）;B组,不锈钢器械（K锉和H锉）＋除丁克溶剂;C组,ProTaper再治疗器械＋除丁克溶剂。记录操作时间。各组用除丁克暂封5min,再使用Endo Activator冲洗,拍摄X线片,评价根管内根充物残留量。结果：A组操作时间显著高于B组和C组（P〈0．05）。B组和C组清洁效果优于A组。根管内暂封除丁克及使用Endo Activator冲洗后残留物显著少于器械操作即刻结束的残留物（P〈0．05）。结论：各种再治疗方法均不能彻底清除根管及峡区内的根充物,除丁克和Endo Activator有助于减少根充物残留。     

根管峡区的定位、发生率及临床意义

根管峡区(root canal isthmus,RCI)是位于同一牙根内、根管之间含有牙髓或牙髓衍生组织,呈现为带状狭窄的连接或含有交通支及横向吻合的解剖学结构,它常存在于含有两个根管的牙根中,解剖结构复杂.不同牙位的RCI发生率不尽相同,发生率最高的部位是下颌第一磨牙近中根和上颌第一磨牙近中颊根.RCI的存在增加了根...     

上颌第一恒磨牙近中颊根尖部根管峡区的研究

目的:通过显微CT技术研究上颌第一恒磨牙近中颊根尖部根管峡区的三维形态特征。方法:收集173颗上颌第一恒磨牙,显微CT扫描及三维重建后,观察近中颊根尖部根管峡区的发生率及其形态特点。结果:173颗上颌第一恒磨牙中128颗牙的近中颊根尖部根管出现峡区,发生率为73.99%;近中颊根距根尖5mm～区段峡区发生率最高,为68.21%;三维重建结果显示,混合型根管峡区所占构成比最高,达60.94%。结论:上颌第一恒磨牙近中颊根尖部根管峡区发生率较高,加强峡区的清理对提高根管治疗成功率具有重要意义。     

上颌第一前磨牙变异根1例

患者男,18岁。因正畸需要常规局麻下拔除双侧上颌第一前磨牙,在拔牙过程中,感觉虽然已经松动,但不易取出,后经仔细颊舌向扭动方才取出。结果发现:牙冠外形虽是双尖牙,但根则是上颌磨牙的三根形态,近、远中颊根、腭侧根。其根长分别为:近中颊根12.5mm、远中颊根11.0mm、腭侧根12.5mm、冠长7.5mm,长度与普通第一前磨牙无差异。上颌第一前磨牙一般为扁的单根牙,或者是双根,但三根者实为罕见。文献报道:三根者约占2.4%。特此提醒广大口腔临床工作者在治疗上颌第一前磨牙时,考虑到其变异较多,不仅有50%的双根管,而且可能还会出现三根管的情况,不…     

上颌第一前磨牙根管系统研究

目的：制作上颌第一前磨牙离体牙透明标本,研究其根管系统解剖形态。方法：100颗上颌第一前磨牙经透明髓腔处理后,直接在体视显微镜下读取根管系统的形态并作规律性统计处理。结果：①上颌第一前磨牙根管口分为单、双两种类型,②主根管形态以2－2型、1－1型和2－1型常见,③侧副管发生率高,根管侧枝和根尖区的细小分支均高达14％,而且伴随双根管出现的管间交通也高达9％。结论：上颌第一前磨牙的根管治疗效果不确定性较大。     

不同超声倒预备尖对根管峡部预备成型的体外实验比较

目的：比较3种超声倒预备尖对哑铃型牙根根管峡部预备成型的差异。方法：120颗由一个峡部连接2个主根管的哑铃型离体上颌前磨牙,随机均分成3组（n ＝40）,分别用超声波配3种倒预备尖对根管峡部进行倒预备：①镍钛尖 RE2,②金刚砂尖 Berutti,③25＃K 锉。扫描电镜评价峡部的边缘质量、微裂数目和类型,采用 SPSS 13．0软件包进行 Kruskal Wallis Test 秩和检验。结果：超声波配镍钛尖 RE2组预备峡部边缘质量优于金刚砂尖 Berutti 组和25＃K 锉组（P ＝0．003）;微裂数目少于金刚砂尖 Berutti 组和25＃K 锉组（P ＝0．003）;3组间微裂类型无统计学差异（P ＝0．830）。结论：超声波配合镍钛尖 RE2倒预备更适用于预备根管峡部。     

离体的上颌第一前磨牙的根管和牙根情况的研究

目的 :观察上颌第一前磨牙的牙根及根管形态。方法 :115个离体的上颌第一前磨牙 ,对牙齿进行近远中向X线照像 ,然后从根中 1/3横断 ,按Vertucci :分类法对根管系统进行记录。结果 :74个牙是单根 (64 % ) ,41个牙是双根 (3 6% ) ,双根牙根管均是Ⅰ型 (1) ,即每个牙均是 2个根管 ,每个根 1个根管 ,而 3 9%的单根牙是 1个根管 ,61%的单根牙有 2个根管 [Ⅱ型 (2 1) ,Ⅳ型 (2 ) ,Ⅴ型 (1 2 ) ]。结论 :上颌第一前磨牙的根管类型相对复杂。     

A preliminary in vitro study of the incidence and position of the root canal isthmus in maxillary and mandibular first molars

AIM: To investigate in vitro the incidence and position of the root canal isthmus in extracted mesiobuccal roots of maxillary and mesial roots of mandibular first molars. METHODOLOGY: Fifty maxillary and 50 mandibular molars were included in the study. The mesiobuccal roots of maxillary molars and the mesial roots of mandibular molars were sectioned from their crowns in the furcation region and embedded in clear resin. Transverse serial 1-mm-thick sections from the apical 6 mm were prepared. The apical side of each section was stained with India ink and observed through a light microscope. The sample images were saved to disk using a digital camera and the root canals in terms of the number present and the incidence and classification of isthmuses. RESULTS: In the mesiobuccal root of the maxillary first molars, 70% had one canal, whereas 29.5% had two canals. In the mesial root of mandibular molars, 41% had one canal, whereas 59% had two canals. In some sections, more than two canals were found close to the apical foramen. The isthmus incidence was greatest 3-5 mm from the apex. In teeth having two canals, a complete or partial isthmus was frequently observed in the sections between 3 and 4 mm from the apex. Of the isthmuses present, 22% were complete and 37% partial in mandibular molars and 17.3% were complete and 11.7% partial in maxillary molars. CONCLUSIONS: The incidence of isthmus in the mesiobuccal root of the maxillary first molars and in the mesial root of the mandibular first molars was high, particularly in sections 3-5 mm from the apex. Cleaning the isthmus is a major challenge during root canal treatment.     

离体上颌第二前磨牙根管和牙根情况的研究

目的观察上颌第二前磨牙的牙根及根管形态。方法213颗离体的上颌第二前磨牙，对牙齿进行近远中向X线照像，并从根中1／3横断探测确实，Vertueei’s分类法对根管系统进行记录。结果185颗牙是单根(87％)，28颗牙是双根(13％)，而单根牙中最多的是1个根管[Type Ⅰ(1)]，占牙齿总数的43％，其次是单根双管TypeⅡ(2-1)，即颊舌2个根管，至根尖又合并成一个根尖孔，占牙齿总数的35％。结论上颌第二前磨牙主要是单根，单个根尖孔的发生率高(78％)。     

应用锥形束CT研究上颌第一前磨牙根管预备前、后管间峡区的结构变化

目的:应用锥形束CT研究根管预备前、后的管间峡区出现率及分型,并探讨锥形束CT在管间峡区研究中的作用和价值.方法:66颗离体单根双根管上颌第一前磨牙根管预备前及预备后,经锥形束CT扫描.记录并比较根管预备前、后管间峡区的出现率及形态.采用SPSS13.0软件包中的x2检验分别比较根管预备前和预备后根尖0～6 mm区域内每1 mm区域的管间峡区(完全峡区和部分峡区)出现率,采用Wilcoxon秩和检验对根管预备前、后根尖0～6mm区域内的管间峡区(完全峡区和部分峡区)出现率进行比较.结果:根管预备前后单根双根管上颌第一前磨牙根尖0～6 mm区域内不同横截面的管间峡区出现率不同(P＜0.05),以根尖1 mm处最低,6 mm处最高;部分峡区比例高于完全峡区(P＜0.05).根管预备后,根尖0～6 mm区域内管间峡区的出现率显著减少(P＜0.05),但完全峡区所占比例增加.结论:锥形束CT可较精确地观察根管预备前、后管间峡区的结构变化,是研究管间峡区比较理想的方法.     

Root and canal morphology of maxillary premolars and their relationship with the crown morphology

ObjectivesTo investigate the relationship between crown/root size and root/canal morphology of maxillary premolars.MethodsOne hundred and thirty-three first (P1) and 110 second (P2) maxillary premolars were used. Mesiodistal and buccolingual diameters and root heights of P1 and P2 were recorded to the nearest 0.01 mm. The number of single and multi-rooted premolars was recorded based on the Turner's classification. Root canal morphology was studied using a clearing technique with Vertucci's classification. Pearson's correlation coefficient was used to analyze the relationship between tooth size and root/canal morphology.ResultsTwo-rooted P1 was found in 33.9% of male and 22.5% of female. P2 showed a single root in 85.4% of male and 82.6% of female. In case of P1, the number of root canals (P<0.05) and apical foramina (P<0.01) was significantly different between male and female. P1 crown dimensions were larger in double-rooted teeth than in single-rooted ones. Significant differences were observed in buccolingual (P<0.05) and crown area (P<0.05) in females. Root height was smaller in double-rooted than in single-rooted P1. A similar trend was observed for P2 with a larger crown size in teeth with two apical foramina compared with those with a single foramen.ConclusionsTwo-rooted P1 with two or more apical foramina are more commonly seen in males than in females. For P1, the correlation of number of roots and apical foramina was stronger with buccolingual diameter than with mesiodistal diameter in both genders. P1 and P2 with large crown dimensions tend to have multiple roots and apical foramina.     

Root form and canal anatomy of maxillary first premolars.

The external and internal anatomy of 240 extracted, maxillary first premolars was studied. The external anatomy was studied by measuring each tooth and by observing the direction of the root curvatures from the facial and proximal aspects. The internal anatomy of the pulp cavity was studied by a method of making the teeth translucent. A total of 55.8% of the teeth had a single root, 41.7% had two roots and 2.5% had three roots. Considering all of the first premolars, 17.1% had one canal, 80.4% had two canals and 2.5% had three canals.