背景:根管治疗是根管疾病的主要治疗方法之一,有效的灌溉是成功治疗的关键。侧通气针是临床上常用的针型之一。在真正的根管中,由于根管曲率的影响,不同针向的灌溉流场表现出明显的差异。同时,根管曲率和工作深度的变化将导致灌溉效率和流场的变化。灌溉流的主流和壁附近的剪切应力都发生了显着变化。因此,根管的置换或涂抹层的去除效率明显改变。
方法:在本文中,直到15/04准备的上颌第一磨牙的永久根管通过显微CT扫描,然后导入到软件中进行三维重建。30G侧针在4.75mm不同工作深度下冲洗效率的关键参数,5mm,比较5.25mm和5.5mm。同时,不同曲率为0°的模拟模型,5°,10°,重建基于真实根管的20°和30°,以研究曲率对灌溉效率的影响。
结果:结果表明,适度的工作深度(例如本文中的4.75mm和5.25mm)有助于提高灌溉流量的替代能力。同时,随着工作深度的增加,根尖压力降低。根管的曲率严重影响根管涂抹层的去除深度。具有较大曲率(尤其是20°和30°)的根管可以显着提高冲洗的难度。
结论:(1)适度的工作深度有助于提高驱替能力,在4.75mm和5.25mm的工作深度处,灌溉流量的ERD通常得到改善,根尖压力随工作深度的增加而减小。(2)根管的大曲率可以显著提高冲洗的难度。根管的曲率会严重影响壁上涂抹层的去除深度。可以发现,对于小曲率(5°和10°)的根管,ESS的跨度和深度都高于大曲率(20°和30°)的根管。
BACKGROUND: Root canal therapy is one of the main treatments for root canal diseases, and effective irrigation is the key to successful treatment. Side-vented needle is one of the commonly used needle types in clinic. In the real root canal, due to the influence of the curvature of the root canal, the irrigation flow field in different needle directions shows obvious differences. At the same time, changes in root canal curvature and working depth will lead to changes in irrigation efficiency and the flow field. Both the mainstream of the irrigation flow and the shear stress near the wall changes significant. Consequently, either the replacement in the root canal or the removal efficiency of the smear layers is apparently modified.
METHODS: In this paper, the permanent root canal of the maxillary first molar prepared until 15/04 were scanned by micro-CT, and then imported into the software for 3D reconstruction. The key parameters of flushing efficiency of 30G side needle at different working depths of 4.75 mm, 5 mm, 5.25 mm and 5.5 mm were compared. Meanwhile, the simulated models with different curvatures of 0°, 5°, 10°, 20° and 30° based on the real root canal were reconstructed to investigate the curvature effect on the irrigation efficiency.
RESULTS: The results show that moderate working depth (such as 4.75 mm and 5.25 mm in present paper) helps to improve the replacement capacity of irrigation flow. At the same time, the apical pressure decreased as the working depth increased. The curvature of the root canal seriously affects the removal depth of the smear layers of the root canal. A root canal with a large curvature (especially 20° and 30°) can significantly improve the difficulty of irrigation.
CONCLUSIONS: (1) Moderate working depth helps to improve the displacement capacity, the ERD of the irrigation flow is generally improved at the working depths of 4.75 mm and 5.25 mm, and the apical pressure will decrease with the increase of working depth. (2) The large curvature of the root canal can significantly improve the difficulty of irrigation. The curvature of the root canal can severely influence the removal depth of the smear layer on the wall. It can be found both the span and the depth of the ESS for little curvatures (5° and 10°) root canals are higher than those for large curvatures (20° and 30°).