Department of Endodontology, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.
Physics of Fluids Group, Faculty of Science and Technology, University of Twente, Enschede, The Netherlands.
Int Endod J. 2022 Sep;55(9):938-949. doi: 10.1111/iej.13791. Epub 2022 Jul 14.
The aim of the study was (a) to develop a three-dimensional numerical model combining the oscillation of a tapered ultrasonic file and the induced irrigant flow along with their two-way interaction in the confinement of a root canal. (b) To validate this model through comparison with experiments and theoretical (analytical) solutions of the flow.
Two partial numerical models, one for the oscillation of the ultrasonic file and another one for the irrigant flow inside the root canal around the file, were created and coupled in order to take into account the two-way coupled fluid-structure interaction. Simulations were carried out for ultrasonic K-files and for smooth wires driven at four different amplitudes in air or inside an irrigant-filled straight root canal. The oscillation pattern of the K-files was determined experimentally by Scanning Laser Vibrometry, and the flow pattern inside an artificial root canal was analysed using high-speed imaging together with Particle Image Velocimetry. Analytical solutions were obtained from an earlier study. Numerical, experimental and analytical results were compared to assess the validity of the model.
The comparison of the oscillation amplitude and node location of the ultrasonic files and of the irrigant flow field showed a close agreement between the simulations, experiments and theoretical solutions.
The model is able to predict reliably the file oscillation and irrigant flow inside root canals during ultrasonic activation under similar conditions.
本研究的目的是(a)建立一个三维数值模型，该模型结合了锥形超声锉的振动以及在根管限制内沿其诱导的冲洗液流动及其两者之间的双向相互作用。(b)通过与实验和流动的理论（分析）解进行比较来验证该模型。
创建了两个部分数值模型，一个用于超声锉的振动，另一个用于锉周围根管内的冲洗液流动，以考虑双向流固耦合。在空气或充满冲洗液的直根管内，对四种不同振幅驱动的超声 K 锉和光滑丝进行了模拟。通过扫描激光测振仪实验确定 K 锉的振动模式，并用高速摄像和粒子图像测速法分析人工根管内的流动模式。分析解从早期研究中获得。对数值、实验和分析结果进行了比较，以评估模型的有效性。
超声锉的振动幅度和节点位置以及冲洗液流场的比较表明，模拟、实验和理论解之间具有很好的一致性。
该模型能够在类似条件下可靠地预测超声激活过程中根管内锉的振动和冲洗液流动。
