根管显微镜在定位上颌磨牙近颊根第二根管中的作用

目的:评价改进开髓口和应用根管显微镜(DOM)定位离体上颌第一、二磨牙近颊根第二根管(MB2)的能力.方法:收集离体上颌第一、二磨牙共550颗.在肉眼、传统三角形开髓口(N.E-1),肉眼、改进开髓口(N.E-2)和根管显微镜辅助(DOM)三种不同条件下分别探查根管,记录MB2数目.结果:N.E-1、N.E-2和DOM三种不同条件下,MB2发现率在上颌第一磨牙分别为34.26%、51.85%和78.24%;第二磨牙分别为16.17%、23.65%和41.32%.改进开髓口和使用DOM可显著提高MB2发现率,与传统开髓口间的差别有统计学意义,P＜0.05.结论:建议将上颌磨牙开髓口由传统的三角形改为斜四边形,并使用合适的放大技术和增强照明,以提高MB2发现率和治疗率.

A vitro study on the location of the second mesiobuccal canal in the mesiobuccal root of the first and second maxillary molars with dental operating microscope

Objective:To observe the effects of different patterns of access cavity on the incidence of the second mesiobuccal canal(MB2)in the mesiobuccal root of the maxillary first and second molars in Chinese population. Methods: 216 first and 334 second human permanent molars were collected for this study.Traditional triangular access cavity,modified access cavity with naked eyes and under dental operating microscope (DOM),the incidences of MB2 in mesiobuccal root were recorded. Results: Under naked eyes, MB2 were located in 112(51.8%)of the first and 79(23.6%)of the second molars respectively. With DOM, 169(78.2%)of the first and 138(41.3%)of the second molars were founded to have MB2.Conclusion:Using a modified access preparation and DOM can increase the incidence of location of the MB2 canals in vitro.