基于单轴拉伸动物实验的牙周膜弹性模量研究  

Research on elasticity modulus of periodontal ligament based on uniaxial tensile tests

作　　者：王耀骏[1] 严斌[1] 吴斌[2] 杨宇[3] 曹丹[1] 傅肄芃 王林[1] 

机构地区：[1]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,江苏南京210029 [2]南京林业大学机械电子工程学院,江苏南京210037 [3]东南大学机械学院,江苏南京211189

出　　处：《南京医科大学学报（自然科学版）》2016年第5期577-582,共6页Journal of Nanjing Medical University(Natural Sciences)

基　　金：国家自然科学基金(81571005;51305208)

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(P>0.05);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(P>0.05);不同牙根部位牙周膜弹性模量差异不显著(P>0.05),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。Objective：The aim of this study was to determine the stress-strain properties of Beagle Dog’s periodontal ligament（PDL）and compare response characteristics of PDL in different root anatomic level and different loading rate status in uniaxial tensile stage for further exploration of the elasticity modulus of PDL. Methods：4 Beagle Dogs were killed before the bone-PDL-tooth complex was cut and the transverse samples were made. The experimental samples were divided into 3 groups according to the anatomic level of the root（cervical margin,mid-root,and apical）,and each group contained 8 samples. Samples were randomly selected by rate of v1=0.05 mm / s and the other four samples by v2=0.01 mm / s. The uniaxial tensile test was performed and stress-strain curves of PDL was obtained. The elastic modulus was obtained by calculating the slope of the straight line in each segment,and paired t test analysis of influence of tensile rate on the elastic modulus of the PDL was carried out. The randomized block design and variance analysis was set to evaluate the difference caused by different anatomic level of the tooth root. Results：All samples of the stress-strain diagram showed a bilinear property. In different rates,the elastic modulus of linear region differed significantly in mid-root（P=0.016 〈 0.05）and apex（P=0.016 〈 0.05）but cervical margin represented no significant difference（P 〉 0.05）. and the elastic modulus of toe region differ significantly in mid-root（P=0.001 〈 0.05）and cervical margin（P=0.002 〈 0.05）but no significant difference in apex（P 〉 0.05）.The difference of elastic modulus was not significant between the different anatomical level of the root（P 〉 0.05）but the difference between the size of toe region was significant（P 〈 0.05）. Conclusion：The tensile stress strain curves of Beagle Dog’s PDL can befitted to the bilinear property. The elasticity modulus varies from 0.021 ± 0.003 MPa to 1.150 ± 0.235 MPa. The tensile rate can significantly af

关 键 词：正畸学 牙周膜 生物力学 动物实验 

分 类 号：R783.5[医药卫生—口腔医学]