基于单轴拉伸动物实验的牙周膜弹性模量研究

发布时间：2018-07-25 11:03

【摘要】：目的 :研究比格犬牙周膜(periodontal ligament,PDL)在单轴拉伸阶段的应力-应变性质,比较牙周膜在不同牙根部位、不同加载速率下的响应状态和特点,进一步探究牙周膜的弹性模量(elasticity modulus,E)变化规律。方法:比格犬4只,取下颌双侧第一臼齿的牙槽骨-牙周膜-牙齿复合体制作水平切片样本,实验样本以所在牙根部位(颈缘、根中、根尖)为依据分为3组,每组8个样本。随机选取4个样本以v1=0.05 mm/s,其余4个样本以v2=0.01 mm/s为速率对牙周膜样本进行单轴拉伸实验,获得牙周膜的应力-应变图线,通过计算各段直线斜率获得牙周膜弹性模量,配对t检验评价拉伸速率对牙周膜弹性模量的影响,随机区组设计方差分析评价不同牙根部位牙周膜弹性模量的差异性。结果:所有样本的应力-应变图线均呈双线性。不同速率下,牙周膜陡坡阶段弹性模量在根中(P=0.026)和根尖(P=0.016)部差异显著,颈缘部差异不显著(P0.05);缓坡阶段弹性模量在根中(P=0.001)与颈缘(P=0.002)部差异显著,根尖部差异不显著(P0.05);不同牙根部位牙周膜弹性模量差异不显著(P0.05),缓坡区间差异显著(P=0.001)。结论 :比格犬牙周膜拉伸应力-应变图线可拟合为双线性图线。其牙周膜弹性模量介于(0.021±0.003)MPa和(1.150±0.235)MPa之间。拉伸速率对牙周膜弹性模量影响较大,牙周膜所处部位对牙周膜弹性模量影响不明显,但对缓坡区间影响明显。
[Abstract]:Objective: to study the stress-strain behavior of periodontal ligamentum in uniaxial tensile stage, and to compare the response state and characteristics of periodontal ligament at different root positions and loading rates. The change of elasticity modulus (E) of periodontal ligament was further investigated. Methods: four Beagle dogs were divided into 3 groups according to the position of the root (cervical margin, middle root, root tip) and 8 samples from the alveolar bone, periodontal ligament and dental complex of the bilateral first molar of the mandible. Four samples were randomly selected to take v1 / 0. 05 mm / s, the other 4 samples were tested by uniaxial tensile test at the rate of v20.01 mm/s. The stress-strain curve of periodontal membrane was obtained, and the elastic modulus of periodontal membrane was obtained by calculating the straight slope of each segment. The effect of tensile rate on the elastic modulus of periodontal ligament was evaluated by paired t test, and the difference of elastic modulus of periodontal ligament at different root sites was evaluated by random block design variance analysis. Results: the stress-strain curves of all samples were bilinear. At different rates, the elastic modulus of periodontal membrane in steep slope stage was significantly different in root (P0.026) and root tip (P0. 016), but not in cervical margin (P0.05), and in mild slope stage (P0. 001) and cervical (P0. 002), the difference was significant in the middle (P0. 001) and cervical (P0. 002). There was no significant difference in root tip (P0.05), no significant difference in elastic modulus of periodontal ligament in different root position (P0.05), and significant difference in gentle slope interval (P0. 001). Conclusion: the tensile stress-strain curve of periodontal membrane in Beagle canine can be fitted as bilinear curve. The elastic modulus of periodontal ligament was between (0.021 卤0.003) MPa and (1.150 卤0.235) MPa. The tensile rate had a great effect on the elastic modulus of periodontal membrane. The position of periodontal ligament had no obvious effect on the elastic modulus of periodontal membrane, but had a significant effect on the interval of gentle slope.
【作者单位】：南京医科大学口腔疾病研究江苏省重点实验室南京医科大学附属口腔医院正畸科;南京林业大学机械电子工程学院;东南大学机械学院;
【基金】：国家自然科学基金(81571005;51305208)
【分类号】：R783.5

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