Characteristics of the Tooth in the Initial Movement: The Influence of the Restraint Site to the Periodontal Ligament and the Alveolar Bone

Abstract

Abstract:It is critical to clarify orthodontic load transfer mechanism from tooth to alveolar bone, and to determine the influence of applied orthodontic force on tooth behaviour. In this study, two dimensional (2-D) finite element (FE) models were constructed to simulate to mechanical behaviour observed during the initial movement of periodontal ligament (PDL) deformation, and to evaluate the effects of the presence of PDL and various restraint sites on tooth behaviour. A 2-D solid FE model of the tooth-PDL-alveolar bone system was constructed and investigated into stress distribution pattern and displacement. The first analysis was carried out with combinations of FE model with and without PDL. The second analysis was compared with three different sites restraint of alveolar bone. By incorporating PDL in FE models, excessively large stress values and deformation generated in a tooth and alveolar bone were relieved. Since restraint conditions did not affect a tooth and PDL, but had an effect on alveolar bone, orthodontic force necessary for tooth displacement was transmitted correctly. The results of this study revealed that inclusion of PDL in FE models is indispensable to transmit orthodontic force appropriately when investigating tooth behaviour for orthodontic treatment. Restrained sites affected stress distribution in alveolar bone.

Toughened and Recyclable Epoxy Networks Featuring Nanostructures and Dynamic Covalent Bonds

“…In all tests, the samples can relax the stress completely to zero, confirming effective recuration of the networks. Notably, the correlation of σ/σ 0 with time ( t ) can be well depicted by using the Maxwell model; the relaxation time (τ), defined as the time for stress to decay to 1/ e of its initial value, can be utilized to estimate the activation energy ( E a ) for the exchange of the boronic ester bond via the Arrhenius equation τ = A e true( prefix− E normala R T true) where A represents the pre-exponential factor; T stands for the absolute temperature; and R is the universal gas constant. The calculated activation energy ( E a ) values, using the linear relationship of ln(τ) as a function of 1/ T , are displayed in the insets of Figure .…”

Features and Possible Causes of the Extreme Precipitation Anomaly in China During Winter 2019/2020

“…The South Branch trough is another important synoptic system that affects winter precipitation in China. There is a significant positive correlation between the activity frequency index of the South Branch trough and the winter precipitation in the south of China (Suo and Ding, 2009;Wu et al, 2020).…”

The Effect of Implant Length and Diameter on Stress Distribution around Single Implant Placement in 3D Posterior Mandibular FE Model Directly Constructed Form In Vivo CT

“…As a result, unlike natural teeth, the load is transmitted directly to the bone. Consequently, implants with bone remodeling are affected by bone morphology and quality to a greater extent than natural teeth [ 6 , 7 ]. For this reason, ensuring a favorable prognosis with implant therapy requires not just biological examination, but also the resolution of mechanical problems.…”