Lee S J, Lee C S, Strittmatter E J
Department of Conservative Dentistry, Yonsei University, Seoul, Korea.
Endod Dent Traumatol. 1991 Apr;7(2):65-8. doi: 10.1111/j.1600-9657.1991.tb00186.x.
The purpose of this study was to evaluate apical extrusion of root canal content using ultrasonic and hand instrumentation. Forty-nine tooth models were fabricated with clear resin. Each model contained a canal in the center. Each tooth model was mounted in a plastic cube (1 x 1 x 2 cm) with white dental plaster so that the coronal 2-3 mm of the model was exposed for instrumentation. Methylene blue dye with glycerin was used as a marker for root canal content. The study consisted of three groups. In group I, Enac ultrasonic instrumentation was used 1 mm from the apex; in group II, Enac ultrasonic instrumentation was used 3 mm from the apex; in group III, K files were used with a push-pull instrumentation technique, 1 mm from the apex. After instrumentation the resin models were extracted and the plaster blocks were sectioned through the long axis of the models. Photographs were made of the area of apical leakage and the amount of dye penetration was measured using a planimeter. There were no differences between hand instrumentation and both ultrasonic groups. At p less than 0.05, ultrasonic instrumentation 3 mm from the apex leaked significantly more than the ultrasonic instrumentation 1 mm from the apex.
本研究的目的是评估使用超声器械和手动器械时根管内容物的根尖挤出情况。用透明树脂制作了49个牙齿模型。每个模型中央有一个根管。每个牙齿模型用白色牙科石膏固定在一个塑料方块（1×1×2厘米）中，使模型的冠方2 - 3毫米暴露以进行器械操作。含有甘油的亚甲蓝染料用作根管内容物的标记物。该研究分为三组。在第一组中，Enac超声器械在距根尖1毫米处使用；在第二组中，Enac超声器械在距根尖3毫米处使用；在第三组中，K锉采用推拉式器械操作技术，在距根尖1毫米处使用。器械操作后，取出树脂模型，将石膏块沿模型的长轴切开。拍摄根尖渗漏区域的照片，并用求积仪测量染料渗透量。手动器械操作组与两个超声器械操作组之间无差异。在p小于0.05时，距根尖3毫米处的超声器械操作的渗漏明显多于距根尖1毫米处的超声器械操作。
