上颌第一前磨牙根管峡区充填技术的实验研究

目的：体外研究配合或不配合使用超声冲洗的条件下连续波热牙胶充填技术和冷侧方加压充填技术对上颌第一前磨牙的根管及根管峡区的充填质量。方法：选择单牙根双根管的上颌第一前磨牙40颗,根管预备后随机分为4组：A组,侧方加压充填;B组,超声冲洗＋侧方加压充填;C组,连续波热牙胶加压充填;D组,超声冲洗＋连续波热牙胶加压充填。充填后拍摄X线片,记录根管类型和峡区发生情况。从根尖方向冠方水平片切牙根,间隔1mm,选择有根管峡区的横断面在体视显微镜下观察其充填质量并进行评分。结果：X线片和横断面上单牙根双根管的上颌第一前磨牙根管峡区的发生率分别为87.5%和90%。D组根管峡区充填质量优于其它3组（P〈0.05）,B组和C组之间无显著性差异,A组充填质量最差。结论：连续波热牙胶充填技术配合超声冲洗能显著提高对根管峡区的处理能力,值得临床推广应用。

In Vitro Study of Obturation Qualities of Isthmus in Maxillary First Premolars

Objective： To evaluate the obturation qualities of root canals and isthmus in maxillary first premolar using two kinds of condensation with or without ultrasonic irrigation in vitro.Methods： A total of 40 maxillary first premolar with single root and two canals were prepared and divided into four groups： Group A,lateral condensation technique;Group B,ultrasonic irrigation and lateral condensation technique;Group C,continuous wave of condensation technique;Group D,ultrasonic irrigation and continuous wave of condensation technique.The radiographic images of each tooth after obturated were taken.The types of root canals and incidences of isthmus in four groups were recorded and compared.And then roots were sectioned at 1 mm interval from apex to coronal,the obturation qualities of the cross-sections with isthmus were observed and scored.Results： The incidences of isthmuses in maxillary first premolar with one root and two canals showed in the radiographic images and cross-section images were 87.5% and 90% respectively.The obturation quality of isthmus in Group D was the highest（P0.05）.There was no significant difference between Group B and C.The obturation quality of isthmus in Group A was the worst.Conclusion： Continuous wave of condensation technique in combination with ultrasonic irrigation may increase the clinical performance of isthmus which is more adaptable to root canal obturation.