不同根管预备方法对根尖孔溢出碎屑和液体的影响

目的 比较手用不锈钢K挫，手用镍仗挫和机用不锈钢K锉，机用镍钛锉行根管预备后，推出根尖孔的牙本质碎屑重量和冲洗液的体积。方法 将80颗单根离体牙分为4组，每组20颗，分别用手用不锈钢K锉，手用镍钛锉，机用不锈钢K锉，机用镍钛锉预备根管。预备过程中从根尖孔推出的牙本质碎屑和液体，用预先称重的离心管收集，测得推出根尖孔的液体体积和牙本质碎屑的重量。结果 机用镍钛锉组推出根尖孔的牙本质碎屑量比其他组少，但四组间无显著性差异。机用镍钛锉组推出根尖孔的液体量较少，四组间有显著性差异。结论 机用镍钛锉用于根管预备推出根尖孔的液体量及牙本质碎屑均较少。

Apical extrusion of debris and irrigants by using two hands and two engines-driven instrumentation techniques

Objective To evaluate the apical extrusions of irrigating solution and dentine debris as a result of canal shaping by different preparation techniques and instruments. Methods Mandibular and maxillary central and lateral incisors with single canal were included. Teeth with one apical foramen and mature apices were selected as the final samples. The specimens were divided into four experimental groups comprising 20 teeth in each group. Each group was instrumented using one of four techniques: stainless-steel K-file(hand instrument) ;Hyflex K-file(hand instrument); profile 04 (rotary instrument); stainless - steel K - file(M4 handpiece motor instrument). Debris and irrigant volume extruded from the apical foramen were collected into pre - weighed centrifuge tubes during instrumentation. Following instrumentation, the volume of extruded irrigant fluid was measured; the weight of dry extruded dentine debris was also established. Results The engine - driven nickel - titanium extruded less debris than that of the others. However, there was no statistical difference amonggroups. The engine - driven nickel - titanium extruded less irrigants than that of the others. There was statistical difference among groups. Conclusion The engine - driven nickel - titanium was associated with less apical extrusion.