Time-dependent mechanical behaviour of the periodontal ligament
Time-dependent mechanical behaviour of the periodontal ligament
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DOI：
10.1243/0954411001535525
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发表时间：
2000-01-01
期刊：
影响因子：
1.8
通讯作者：
Kuijpers-Jagtman, AM
中科院分区：
文献类型：
--
作者：
van Driel, WD;van Leeuwen, EJ;Kuijpers-Jagtman, AM
牙齿在正畸力作用下的位移过程被认为是由牙周组织中的应力和应变引起的。牙齿上的机械力通过一层软结缔组织，即牙周膜，传递到牙槽骨。该层中的应力和/或应变分布必须从数学模型（例如有限元法）导出，因为它不能以非破坏性的方式直接测量。需要将组成组织的材料行为作为这种模型的输入。本研究的目的是确定牙周膜的时间依赖性的机械行为，由于正畸负荷的牙齿。因此，对比格犬进行了体内实验。在有限元模型中模拟实验配置，以估计牙周膜的多孔弹性材料特性。实验显示了两步响应：4 s内的瞬时位移为14.10 +/- 3.21 μ m，5 h后更渐进的（蠕变）位移达到最大值60.00 +/- 9.92 μ m。当21%的韧带体积的渗透率被指定为1.0 x 10（-14）m（4）/N s时，该响应在有限元模型中非常适合，其余97%的韧带体积的渗透率被指定为2.5 x 10（-17）m（4）/N s。估计组织弹性模量为0.015 +/- 0.001 MPa。我们的研究结果表明，牙周膜内的流体隔间发挥重要作用，在传输和阻尼力作用于牙齿。
The process of tooth displacement in response to orthodontic forces is thought to be induced by the stresses and strains in the periodontium. The mechanical force on the tooth is transmitted to the alveolar bone through a layer of soft connective tissue, the periodontal ligament. Stress and/or strain distribution in this layer must be derived from mathematical models, such as the finite element method, because it cannot be measured directly in a non-destructive way. The material behaviour of the constituent tissues is required as an input for such a model. The purpose of this study was to determine the time-dependent mechanical behaviour of the periodontal ligament due to orthodontic loading of a tooth. Therefore, in vivo experiments were performed on beagle dogs. The experimental configuration was simulated in a finite element model to estimate the poroelastic material properties for the periodontal ligament. The experiments showed a two-step response: an instantaneous displacement of 14.10 +/- 3.21 mum within 4 s and a more gradual (creep) displacement reaching a maximum of 60.00 +/- 9.92 mum after 5 h. This response fitted excellently in the finite element model when 21 per cent of the ligament volume was assigned a permeability of 1.0 x 10(-14) m(4)/N s, the remaining 97 per cent was assigned a permeability of 2.5 x 10(-17) m(4)/N s. A tissue elastic modulus of 0.015 +/- 0.001 MPa was estimated. Our results indicate that fluid compartments within the periodontal ligament play an important role in the transmission and damping of forces acting on teeth.