改良开髓洞形应用于寻找上颌第一磨牙近中颊根第二根管的研究

The Impact of Improved Access on Detection of the Second Mesiobuccal Canal of Maxillary First Molar

目的探讨改良开髓洞形对寻找上颌第一磨牙近中颊根第二根管(second mesiobuccal canal,MB2)的影响。方法选择95颗离体上颌第一磨牙,先用牙钻在面预备出传统的三角形开髓洞形,揭髓室顶,寻找MB2根管;然后将未找到MB2根管的离体牙的开髓洞形扩展为梯形洞形,重新寻找MB2根管。结果开髓洞形为传统三角形洞形时上颌第一磨牙MB2根管的发现率为41.05%(39/95),开髓洞形扩展为梯形洞形又有15颗找到MB2根管,MB2根管的发现率提高到56.84%(54/95),应用梯形开髓洞形的上颌第一磨牙MB2根管发现率大于应用三角形开髓洞形,差异有统计学意义(χ2=4.74,P<0.05)。结论应用梯形开髓洞形可以提高上颌第一磨牙MB2的发现率。

Objective To evaluate the effect on the second mesiobuceal canal（MB2） finding with different access preparation in the maxillary first molar. Methods Nintv-five extracted maxillary first molars were prepared by traditional triangle-shaped to locate the MB2. and then a modification of access preparation to a trapezoid-shaped was used in the samples in which the MB2 cannot be found. Results MB2 was located in thirty-nine samples with the triangular outline, while another fifteen MB2 orifices were located with the trapezoid-shaped. The incidence of the MB2 can he improved from 41.05% to 56.84% Conclusion Detection rate of MB2 can be greatly improved by the use of access preparation of a trapezoid-shaped .