AIM To develop a laboratory-based tooth model of simulated blood flow in teeth and evaluate it using ultrasound Doppler flowmetry (UDF). METHODOLOGY A laboratory-based tooth model for UDF was created based on a microfluidic phantom proposed by Kim & Park (2016). Twenty-one maxillary or mandibular anterior human teeth within one month of extraction were used. Four holes in each tooth including those at the apical foramen, palatal surface in the center of the crown, palatal surface apical to the cementoenamel junction (CEJ) and the root centre, were made to fit a 1.6mm diameter polytetrafluoroethylenen (PTFE) tube. Fluid mimicking pulsating blood was pumped (pressure range: 0-200 mbar, flow rate range: 0-80 μL/min) into the apical foramen via the PTFE tubes, which exited the tooth through the palatal surface in the crown centre (control group), palatal surface underneath CEJ (group 1), and the palatal surface at the mid-root level (group 2). An UDF transducer of 20MHz was placed at a 60° angle to the labial surface of tooth and was used to measure the fluid flow velocity (Vs,Vas,Vm,Vam,Vd, Vad, and Vakd). The flow velocity of the different groups was compared using the Wilcoxon signed-rank test, with a 95% confidence level. RESULTS UDF facilitated the detection of the simulated pulpal blood flow in the control group and group 1, but not in group 2. The mean and standard deviations of Vas, Vam, Vakd were 0.921±0.394 cm/s, 0.479±0.208 cm/s, and 0.396±0.220 cm/s, respectively, in the control group, and 0.865±0.368 cm/s, 0.424±0.215 cm/s, and 0.487±0.279 cm/s, respectively, in group 1. The pulpal blood flow values of the control group and group 1 were not significantly different (p>0.05). CONCLUSIONS This laboratory study showed that the UDF enabled the detection of simulated blood flow under the cemento-enamel junction level but not at the mid-root level.

中文翻译：

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使用超声波多普勒血流仪检测人拔牙后模拟牙髓血流的实验室研究。

目的开发基于实验室的牙齿模拟血流模型，并使用超声多普勒血流仪（UDF）对其进行评估。方法论基于金和帕克（Kim＆Park，2016）提出的微流体模型，建立了基于实验室的UDF牙齿模型。拔牙后一个月内使用二十一个上颌或下颌前牙。制作每个牙齿上的四个孔，包括在顶端孔的孔，在冠中心的pa表面，在牙骨质釉质连接点（CEJ）和根中心的顶表面，以适合直径1.6mm的聚四氟乙烯（PTFE）管。通过PTFE管将模拟脉动性血液的液体泵入（压力范围：0-200 mbar，流速范围：0-80μL/ min），将其通过顶冠中心的lat表面从牙齿中排出（对照组） ），CEJ下方的surface表面（第1组），中根水平的the表面（第2组）。将20MHz的UDF传感器与牙齿的唇面成60°角放置，并用于测量流体流速（Vs，Vas，Vm，Vam，Vd，Vad和Vakd）。使用Wilcoxon符号秩检验比较不同组的流速，置信度为95％。结果UDF有助于在对照组和第1组而不是第2组中检测模拟的牙髓血流。Vas，Vam，Vakd的平均值和标准偏差分别为0.921±0.394 cm / s，0.479±0.208 cm / s在对照组中，分别为0.396±0.220 cm / s，在第1组中分别为0.865±0.368 cm / s，0.424±0.215 cm / s和0.487±0.279 cm / s。对照组和第1组的差异无统计学意义（p> 0。05）。结论这项实验室研究表明，UDF能够在牙釉质-牙釉质结合点水平而非中根水平下检测到模拟的血流。