Benaissa Ali, Merdji Ali, Bendjaballah Mohamed Z, Ngan Peter, Mukdadi Osama M
Laboratory LSTE, Faculty of Science and Technology, University of Mascara, Mascara 29000, Algeria.
Department of Mechanical Engineering, Faculty of Science and Technology, University of Mascara, Mascara 29000, Algeria.
Comput Methods Programs Biomed. 2020 Oct;195:105569. doi: 10.1016/j.cmpb.2020.105569. Epub 2020 May 26.
Mini-implants have been developed and effectively used by clinicians as anchorage for orthodontic tooth movement. The objective of this study was to elucidate the stress response of orthodontic forces on the periodontal system, bone tissues, mini-implant and the bracket-enamel interface.
Computer tomography images of a commercially available mini-implant, an orthodontic bracket bonded to a central incisor, and jawbone section models were used to reconstruct three dimensional computer models. These models were exported and meshed in an ABAQUS finite-element package. Material properties, multi-segment interactions, boundary and loading conditions were then applied to each component. Finite-element analyses were conducted to elucidate the effect of orthodontic force on the equivalent von Mises stress response within the simulated orthodontic system.
The highest stress values in the orthodontic system were predicted at the mini-implant neck, at the interface of the cortical bone, and gradually decreased in the internal apical direction of the miniscrew. On the alveolar bone, the maximum stress values were located in the alveolar cortical bone near the cervical areas of the mini-implant, which is in line with clinical findings of area where bone loss was found post orthodontic tooth treatment. Another peak of von Mises stress response was found in the enamel bracket junction with a maximum up to 186.05 MPa. To ensure good bonding between the enamel and bracket, it is vital to select carefully the type and amount of bonding materials used in the bracket-enamel interface to assure an appropriate load distribution between the teeth and alveolar bone. The results also revealed the significance of the periodontal ligaments, acting as an intermediate cushion element, in the load transfer mechanism.
This study is sought to identify the stress response in a simulated orthodontic system to minimize the failure rate of mini-implants and bracket loss during orthodontic treatment.
微型种植体已被临床医生开发并有效地用作正畸牙齿移动的支抗。本研究的目的是阐明正畸力对牙周系统、骨组织、微型种植体和托槽 - 牙釉质界面的应力反应。
使用市售微型种植体、粘结于中切牙的正畸托槽以及颌骨切片模型的计算机断层扫描图像来重建三维计算机模型。这些模型被导出并在ABAQUS有限元软件包中划分网格。然后将材料特性、多段相互作用、边界和加载条件应用于每个组件。进行有限元分析以阐明正畸力对模拟正畸系统内等效冯·米塞斯应力反应的影响。
正畸系统中预测的最高应力值出现在微型种植体颈部、皮质骨界面处，并沿微型螺钉的根尖内部方向逐渐降低。在牙槽骨上，最大应力值位于微型种植体颈部区域附近的牙槽皮质骨中，这与正畸牙齿治疗后发现骨质流失区域的临床发现一致。在牙釉质 - 托槽连接处发现了另一个冯·米塞斯应力反应峰值，最大值高达186.05MPa。为确保牙釉质与托槽之间的良好粘结，在托槽 - 牙釉质界面仔细选择粘结材料的类型和用量以确保牙齿与牙槽骨之间适当的载荷分布至关重要。结果还揭示了牙周韧带作为中间缓冲元件在载荷传递机制中的重要性。
本研究旨在确定模拟正畸系统中的应力反应，以尽量减少正畸治疗期间微型种植体的失败率和托槽脱落。
