al Shalabi R M, Omer O E, Glennon J, Jennings M, Claffey N M
Department of Restorative Dentistry & Periodontology, School of Dental Science, Trinity College, Dublin, Ireland.
Int Endod J. 2000 Sep;33(5):405-14. doi: 10.1046/j.1365-2591.2000.00221.x.
The aim of this investigation was to study the root canal anatomy of maxillary first and second molar teeth from an Irish population sample using a clearing technique.
Eighty-three extracted permanent maxillary right first molars and 40 permanent right maxillary second molars were included in this investigation. The specimens were demineralized and then cleared using methyl salicylate. The following observations were made: number of roots, prevalence of fusion, types of root canals using Vertucci's classification, presence and position of lateral canals, presence and position of transverse anastomoses, number and position of apical foramina and the frequency of occurrence of apical deltas.
Eleven per cent of maxillary first molars and 43% of maxillary second molars had fused roots. A total of 78% of mesiobuccal roots in maxillary first and 58% in maxillary second molars had two canals. Sixty-two per cent of maxillary first and 50% of maxillary second molars had two apical foramina. There was a significant inverse relationship between age and the occurrence of two canals and between age and the occurrence of transverse anastomoses in both tooth morphotypes (P < or = 0.05).
It is concluded that a significant proportion of the first and second molar specimens studied had two canals in the mesiobuccal root (78% and 58%, respectively) and that the occurrence of two canals and transverse anastomoses decreased significantly with increasing age.
本研究旨在采用透明技术，对爱尔兰人群样本中的上颌第一和第二磨牙的根管解剖结构进行研究。
本研究纳入了83颗拔除的上颌右侧第一恒磨牙和40颗上颌右侧第二恒磨牙。标本先进行脱矿处理，然后用冬青油进行透明处理。进行了以下观察：牙根数量、融合发生率、采用维尔图奇分类法的根管类型、侧支根管的存在情况和位置、横向吻合的存在情况和位置、根尖孔的数量和位置以及根尖分歧的发生频率。
11%的上颌第一磨牙和43%的上颌第二磨牙有融合根。上颌第一磨牙中78%的近中颊根和上颌第二磨牙中58%的近中颊根有两个根管。62%的上颌第一磨牙和50%的上颌第二磨牙有两个根尖孔。在两种牙型中，年龄与双根管的发生率以及年龄与横向吻合的发生率之间均存在显著的负相关关系（P≤0.05）。
得出的结论是，在所研究的第一和第二磨牙标本中，有相当比例的近中颊根有两个根管（分别为78%和58%），并且双根管和横向吻合的发生率随着年龄的增长而显著降低。
