【作者】 于洪友；

【导师】 白丁；

【作者基本信息】 四川大学 ， 口腔临床医学， 2006， 硕士

【摘要】 牙根的吸收和修复经常存在于正畸牙移动过程中。成牙骨质细胞在牙根修复过程中具有重要的意义。位于牙根表面的成牙骨质细胞可以抵抗破骨细胞的附着，从而避免牙根吸收；在已吸收的牙根表面，成牙骨质细胞分泌形成新生的牙骨质样组织对其进行修复。当牙根吸收与修复平衡被打破后，牙根吸收形成。正畸牙移动过程中，机械张应力对成牙骨质细胞矿化功能的影响尚不清楚，国内外尚未见报导。 本研究目的是建立一种新的体外培养成牙骨质细胞方法，采用四点弯曲加力系统，以成牙骨质细胞为研究对象建立细胞应力刺激体外模型，检测在不同刺激强度、不同作用时间的张应力刺激下，成牙骨质细胞矿化相关基因BSP mRNA的表达，在分子生物学水平上研究张应力刺激对成牙骨质细胞矿化功能表达的影响，探讨在正畸牙移动过程中，机械张应力对成牙骨质细胞矿化功能的影响。 结果显示： 1、体外分离培养牛来源的成牙骨质细胞表达牙骨质黏附蛋白、碱性磷酸酶、骨桥蛋白及骨钙素。 2、体外培养的成牙骨质细胞可在体外形成矿化组织，具有矿化功能。 3、张应力刺激可促进成牙骨质细胞的BSP mRNA的表达，2000με表达BSP mRNA较4000με应力强。更多还原

【Abstract】 Background and objective: Root Resorption is a common consequence of orthodontic teeth movement. Cementoblast plays important roles in the progress of root resorption and repair. Cementoblast is located on the surface of the root cementum to inhibit the attachment of the osteoclasts and form the new cementum-like tissue in the lacuna on the resorpted root surface. The pathologic resorption is formed when the balance of the resorption and repair is disturbed. The development of the strain apparatuses in vitro has allowed investigate the effects of the mechanical stimuli on cementoblasts functions. To understand and control effects of strain on cementum forming, It is essential to learn the effects of mechanical strains on the cementoblasts. The goal of this research is to determine the effects of the mechanical strain on the expression of the mineral associated gene in cementoblasts in vitro.Methods: Cementoblasts was isolated from the cementum of the bovine root surface. The expression of cementum-derived attachment proteins, bone sialoproteins, osteopotin was examined by cell immunochemistry. The cementoblasts was cultured with the osteogenic medium for 13 days; the deposit of the calcium was evaluated by Von Kossa stain. The cementoblasts was loaded mechanical strain by four points bending system for 3,6,12,24 and 36 hours, the static mechanical strain magnitude was 2000με and 4000με, strain cycle was set to lcycle/sec(0.5Hz). After loading the mechanical strain,更多还原