上颌第一磨牙近中颊根第二根管的治疗体会

目的探讨在临床上上颌第一磨牙近中颊根第二根管(MB2)的发现及扩通。方法在25例需要进行根管治疗的上颌第一磨牙上寻找MB2,若无法找到,使用超声根管异物清除工作尖10P清理髓底及慢速圆钻去除预计位置部分牙本质,再次寻找。找到后通畅根管,若无法扩通,使用慢速圆钻在MB2根管口处向根方去除少量牙本质,结合使用EDTA再次通畅根管。结果25颗治疗齿中有13颗找到MB(252%),其中2颗是在超声根管锉清理髓室底后发现的,4颗在进一步去除MB2根管口位置的牙本质后发现。8颗治疗齿的MB2通畅(32%),其中3颗自然扩通,5颗在去除MB2根管口处部分牙本质并使用EDTA后通畅。结论临床上上颌第一磨牙MB2发现率为52%,扩通率为32%。掌握MB2的解剖位置,使用超声方法以及EDTA可提高MB2的发现率和扩通率。

The experience in the treatment of the second mesiobuccai root canall (MB2) in maxillary first molars

Objective To investigate the clinical discovery and expanding of the second mesiobuccal canal (MB2) in maxillary first molars. Methods Search the MB2 in maxillary first molars among 25 teeth which received root canal treatments. If MB2 could not be found, to try again after cleaning the floor of pulp chamber by using 10P tip of the retrieval instruments and removal part of dentin on the location estimated by slow-speed round bur. Then, to negotiate the root canal. If the negotiation failed, to remove small amount of dentin by using the slow-speed round bur from the root canal orifice to the direction of MB2 root, then to negotiate the root canal once more accompany with EDTA. Results Among the 25 teeth treated, there were 13 teeth (52%) in which the MB2 were found. Two of them were found after cleaning the chamber floor by ultrasonic file. 4 of them were found after removal part of dentin near the MB2 orifice. MB2 of 8 teeth were negotiated (32%), 3 of them were negotiated directly, 5 of them were negotiated after removing dentin near the MB2 orifice and adding EDTA. Conclusion The 52% of MB2 orifice can be located. And the rate of expanding is 32% . Understanding the position of MB2 and using the ultrasonic method accompany with EDTA are helpful to increase the location and negotiation of MB2.