title: Root canal anatomy of maxillary first and second permanent molars.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  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).
  
  
  CONCLUSIONS
  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.
authors: Department of Restorative Dentistry & Periodontology, School of Dental Science, Trinity College, Dublin, Ireland.
authors: R M
authors: RM
authors: al Shalabi
authors: O E
authors: OE
authors: Omer
authors: J
authors: J
authors: Glennon
authors: M
authors: M
authors: Jennings
authors: N M
authors: NM
authors: Claffey
mesh_terms: D000328:Adult; D000367:Age Factors; D016009:Chi-Square Distribution; D003786:Dental Pulp Cavity / Q000033:anatomy & histology*; D006801:Humans; D007494:Ireland; D008437:Maxilla; D008875:Middle Aged; D008963:Molar / Q000033:anatomy & histology*; D019227:Tooth Apex / Q000033:anatomy & histology