Micro-CT study on the root canal morphology of the maxillary first permanent molar in the Chinese popula-tion
Objective:To study the root canal anatomy of maxillary first permanent molar with micro-computed tomo-graphy(micro-CT).Methods:Totally 190 maxillary first permanent molars with bifurcated roots were scanned by micro-CT,and the images of the root canal systems were reconstructed.The three-dimensional morphology of root canals was studied,and the incidence of accessory canal,root canal loops,intercanal communication,isthmuses,MB2,and apical delta were recorded.The apical constriction types were classified.The numbers of apical foramina were recorded.Results:25.3%of mesiobuccal root canals were type 2-2,and 83.2%.of distobuccal root canals and 92.1%palatal root canals were type 1-1.The incidences of accessory canals,intercanal communications,isthmus,and apical delta in mesiobuccal roots were significantly higher than those in distobuccal roots and palatal roots(P<0.05).MB2 was present in 81.6%of mesiobuccal roots.The incidence of api-cal constriction was low,and when present the most common type was the single constriction type.80.5%of mesiobuccal roots had more than two apical foramina,67.4%of distobuccal roots and 70.5%of palatal roots had only one apical foramen,and the number of apical foramina among the three roots was statistically different(P<0.05).Conclusion:The root canal of the maxillary first permanent molar is complex and diverse,especially in the mesiobuccal root.Clinical root canal treatment should focus on enhancing the effectiveness of both mechanical instrumentation and chemical disinfection.
Micro-CTMaxillary first permanent molarRoot canal morphologyIsthmus