Mechanical Behavior of Human Cancellous Bone in Alveolar Bone under Uniaxial Compression and Creep Tests

Abstract

In the process of orthodontic treatment, the remodeling of cancellous bone in alveolar bone (in this paper, cancellous bone in alveolar bone is abbreviated as CBAB) is key to promoting tooth movement. Studying the mechanical behavior of CBAB is helpful to predict the displacement of teeth and achieve the best effect of orthodontic treatment. Three CBAB samples were cut from alveolar bone around the root apex of human teeth. A uniaxial compression test was used to study the transient elastic properties of CBAB. A creep test was used to study the time-dependent viscoelastic properties of CBAB. Both tests were carried out at the loading rates of 0.02 mm/min, 0.1 mm/min and 0.5 mm/min. The results revealed that CBAB is a nonlinear viscoelastic and hyperelastic material. The stress–strain curve obtained from the uniaxial compression test could be divided into three stages: the collapse stage of the front section, the exponential stage of the middle section and the almost linear stage of the rear end. According to the strain–time curve obtained from the compression creep test, a trend of increasing strain over time was relatively obvious within the first 30 s. After 200 s, the curve gradually tended to plateau. Four hyperelastic models and three viscoelastic models were used to fit the test data. Finally, the fifth-order polynomial hyperelastic model (coefficient of determination “R2 > 0.999”) was used to describe the hyperelastic properties of CBAB, and the seven-parameter model of the generalized Kelvin modified model (“R2 > 0.98”) was used to describe the viscoelastic properties of CBAB.

Finite element analysis of a new alveolar bone splitting technique in the mandibular posterior region

“…Besides, it could be found that the equivalent stress and equivalent strain distributions were inconsistent when the jaw model was in the ultimate yielding state. For example, when the 3 mm jaw model was in the ultimate yielding state, the buccal and lingual cancellous bone at the root incision had already experienced equivalent stress continuity, but the equivalent strains were still distributed only in the super cial layers of the buccal and lingual cancellous bone; when the equivalent stress at the edge of the free cortical bone had already exceeded the shear strength, the corresponding equivalent strain exceeding the yield strength was not observed, which may be related to the phenomenon of "hysteresis" [17] in osteo-viscoelasticity, where the strain response lags behind the stress. It is worth noting that during bone expansion, the stresses and strains were more concentrated in the cancellous bone and external cortical bone located in the region of the root incision, as well as in the lower 1/3 of the buccal lamellae of the free cortical bone, which suggests that in some cases of thin cortical bone, as the force increases, the buccal lamellae breakage may be located in the lower 1/3 of the lamellae, in addition to occurring in the root incision location.…”

Construction of a Viscoelastic Model of Human Cancellous Bone in Alveolar Bone Based on Bone Mineral Density Distribution

“…Alveolar bone is divided into three parts: intrinsic alveolar bone, cancellous bone, and cortical bone [1]. Alveolar bone changes actively during orthodontic treatment, which is bone remodeling.…”