Clinical treatment of second mesiobuccal canals of maxillary first molars

Objective:To discuss the feature and clinical treatment of second mesiobuccal canal (MB2)of permanent maxillary first molars. Methods:The root canals of 112 permanent maxillary first molars were explored with small size K files and 15%EDTA. The morphology and type of root canal system were recorded. The canals of all cases were instrumented by Ni-Ti rotary instruments Hero 642, and obturated with lateral condensation technique. The efficiency of preparation and obturation was analyzed with radiographs before and after treatment. Results:The frequency of MB2 canal in maxillary first molars was 82.4%. Most of MB2 were fine and curved, and could be negotiated by 8 or 10# file combined with EDTA. No complication, such as transportation, ledge and perforation, was found during the root canal preparation. Good result of treatment was achieved in almost all cases. Conclusion:The incidence of MB2 canals in maxillary first molars was high, and most of them were fine and curved. The MB2 canals can be negotiated with small size file and EDTA, and shaped well with Ni-Ti rotary instruments.