牙周再生后正畸牙移动过程中成骨三种因子的表达

Expression of osteogenetic factors during tooth movement after periodontal regeneration

关键词:  双相磷酸钙  牙周再生  骨改建  Cbfα1  Osterix  Smad4

Key words:  biaphasic calcium phosphate  periodontal regeneration  bone remodling  Cbfαl  Osterix  Smad4

摘要:

目的研究以骨髓基质干细胞（bone mesenchymal stem cells，BMSCs）作为种子细胞，改良的双相磷酸钙（biaphasic calcium phosphate，BCP）作为支架材料，应用组织工程学方法再生的牙周组织在施以正畸力后发生骨改建的变化过程中成长因子的表达情况。方法选用雄性成年比格犬6只，体外培养其BMSCs并接种于改良的BCP，随后拔除其双侧上下颌第一前磨牙，实验组于第二前磨牙近中根颊侧制造牙周组织缺损，将体外共培物植入缺损部位，以自身为对照组，不予任何手术处理。牙周再生20周后施以正畸力，以尖牙为支抗，拉第二前磨牙向近中移动，控制正畸力为150g，于加力后1、2、4周分别处死2只犬，取材。Real-TimePCR及Western印迹法检测再生的牙周组织中Cbfα1、Osterix及Smad4的表达。结果实验组与对照组Cbfα1、Osterix及Smad4表达趋势相同，程度相似：加力l周时呈阳性表达，2周时达高峰，第4周时阳性表达均减弱但仍高于1周时的表达量，Cbfα1、Osterix及Smad4的阳性表达情况与正常牙周组织相比，差异无统计学意义。结论应用改良的BCP再生的牙周组织在被施以正畸力后发生牙周组织改建，其变化过程与趋势与正常牙周组织相似。

Abstract:

Objective To investigate the expression of osteogenetic factors during tooth movement after periodontal regeneration with bone mesenchymal stem cells（BMSCs） as seed cells and improved biaphasic calcium phosphate （BCP） as scaffold. Methods Premolars were extracted and alveolar defects were made in huccal aspect of mesial root of the second premolar in six male and healthy beagle dogs. The BMSCs from the dog were cultured as seed cells and inoculated in improved BCP. The BMSC-improved BCP scaffold was implanted into alveolar defects; the contralateral side with no surgery was used as control. Orthodontic movement was initiated 20 weeks after surgical operation with 150 g force, and then two dogs were sacrificed randomly after 1, 2 and 4 weeks, the expressions of Cbfαl, Osterix and Smad4 in periodontal tissues were detected by Real-Time PCR and Western blotting. Results The expression of Cbfα1, Osterix and Smad4 in periodontal tissues were increased with the time and reached to the peak at 2 weeks after operation. There were no significant differences in expression of these osteogenetic factors between two groups. Conclusion During the orthodontic movement the expression of osteogenetic factors in regenerated periodontal tissue is not different from that in normal periodontal tissue.