【作者】 王静；

【导师】 孙新华；

【作者基本信息】 吉林大学 ， 口腔临床医学， 2011， 硕士

【摘要】 目的:通过局部注射特定寡核苷酸(oligodeoxynucleotides, ODN),观察大鼠实验性牙移动的距离及牙周组织形态的变化,检测局部牙周组织中RANKL和Ⅰ型胶原的表达,探讨特定ODN对大鼠实验性牙移动骨改建的影响作用。方法:选用7周龄SPF级健康雄性Wistar大鼠40只,体重221±18g,随机分为实验组与对照组,每组20只。建立实验性大鼠牙移动模型,以上颌切牙为支抗,40g力拉上颌第一磨牙向近中移动。加力当天于实验组大鼠两侧上颌第一磨牙颊侧牙龈黏膜下各注射特定ODN MT01(20μg/ml)50μl,对照组大鼠相同部位注射等量的PBS溶液。每3d给药一次。取加力3d、7d、14d、21d、28d五个时间点每组各处死4只大鼠。两组大鼠均于牙移动装置安置前和处死前取印模,制作超硬石膏模型后测定牙移动距离;并于心脏灌注处死后取上颌第一磨牙及其周围牙周组织制作石蜡切片,经HE染色观察牙周组织形态变化并进行破骨细胞计数,经免疫组织化学染色图像分析观察RANKL和Ⅰ型胶原表达水平的变化。结果:①实验组除加力3d外,其他各观察时间点大鼠第一磨牙牙移动距离均小于对照组,差异有统计学意义(P<0.05);②HE染色观察显示,实验组大鼠第一磨牙压力侧牙槽骨吸收程度轻于对照组,且破骨细胞数也少于对照组,其中3d、7d时差异最显著(P<0.01);③免疫组织化学图像分析显示,实验组与对照组大鼠第一磨牙牙周组织Ⅰ型胶原的表达水平呈逐渐增加至14d达到峰值后降低的趋势,且实验组Ⅰ型胶原阳性表达的平均光密度值全程大于对照组,7d、14d、21d时有显著差异(p<0.05);实验组和对照组RANKL的表达水平呈7d时达峰值,而后逐渐降低的趋势,且各观察时点实验组RANKL阳性表达的平均光密度值均小于对照组,7d、14d两组间差异显著(p<0.01),21d、28d时差异无统计学意义。结论:在大鼠实验性牙移动过程中,特定ODN减少了压力侧牙槽骨表面破骨细胞的数量,抑制了实验性牙齿移动;特定ODN还增强了牙周组织内Ⅰ型胶原的表达并减弱了RANKL的表达,进一步证实特定ODN对大鼠实验性牙移动骨改建具有影响作用。更多还原

【Abstract】 Objective:The purpose of the present experiment is to study the effect of the specific sequence oligonucleotide (oligodeoxynucleotides, ODN) on the distances of tooth movement ;to study the changes of periodontium structure, and the expressions of RANKL and typeⅠcollagen which are contained in the periodontal tissue of the rats;then to investigate the effect of this specific ODN on the control of tooth movement and alveolar bone remodeling.Method:40 male Wister rats which were 7 weeks old (weight 221±18g) were randomly divided into experimental group and control group, n = 20. then according to the observation point, each group was divided into 3d, 7d , 14d, 21d, and 28d’s observation group,n=4. Under the anchorage of rats’maxillary front teeth, established model of experimental tooth movement in rats in order to pull the maxillary first molar move mesial by the force of 40g.After that, the buccal gingival mucosa of the maxillary first molar of the experimental group was injected with 50μl ODN (20μg/ml), and the control group was injected with the same amount of PBS, administered once every 3d. The rats of each observation group of the experimental group and control group were killed on its observation point. The plaster models of rats’upper mandible were made to measure the distance of tooth movement , afer the tooth moving models were erected and before tha rats were killed.Then the maxillary first molar and its periodontium were got from the dead rats.By the way of HE stain and immunohistochemistry stain to observe the changes of periodontium structure, and the expressions of RANKL and typeⅠcollagen which were contained in the periodontal tissue.Results:①Besides the 3rd day , the moving distances of the first molars of the experimental groups were less than the control group, and the difference was statistically significant (P <0.05).②HE staining showed that the absorption of pressure side of the first molar alveolar bone in the the experimental group was less than the control group.Furthermore the number of osteoclasts was also less than the control group,especially the 7 th day (P <0.01). ③The image of immunohistochemistry staining revealed that expression of typeⅠcollagen , which was contained in the periodontal tissue of rats ,gradually increased to peak in the 14 th day, then decreased.The collagen typeⅠin the experimental group was greater than the control group, especially the day of 7 th,14 th and 21th(p <0.05).But the expression of RANKL in periodontium of both the experimental group and control group had its peak in the 7 th day,and then gradually decreased. Moreover the expression of RANKL of the experimental group were less than the control group, especially the day of 7 th,14 th and 21th (p <0.01),But in the day of 21 th and 28 th the the difference between the two groups had not statistically significant.Conclusion:In rats model of experimental tooth movement, the specific ODN can reduce the number of osteoclasts on the pressure side of the alveolar bone surface and inhibit experimental tooth movement. After that this specific ODN can also enhance the expression of typeⅠcollagen and reduce the expression of RANKL, which were contained by periodontal tissue. All of these show that the specific ODN can affect on the control of tooth movement and alveolar bone remodeling.更多还原