Jäger Andreas, Kunert Dominique, Friesen Therese, Zhang Dongliang, Lossdörfer Stefan, Götz Werner
Department of Orthodontics, University of Bonn, Bonn, Germany.
Eur J Orthod. 2008 Aug;30(4):336-45. doi: 10.1093/ejo/cjn012. Epub 2008 Jul 16.
The aim of this study was to investigate the role of extracellular matrix components, such as collagen type I, fibronectin, and osteopontin (OPN) during cementum repair following experimentally induced tooth movement, and to characterize the cells taking part in the regenerative process. The upper right first molars were moved mesially in 21 three-month-old male Wistar rats using a coil spring with a force of 0.5 N. After 9 days, the appliance was removed and the animals were killed in groups of three immediately after withdrawal of the force and 5, 7, 10, 12, 14, and 17 days later. Three rats served as non-experimental control animals. The maxillae were prepared and processed for histological analysis. Together with the disappearance of the multinucleated odontoclasts from the resorption lacunae, signs of repair were visible 5 days after the release of the orthodontic force. The first signs of cementum repair were seen on day 10. The newly produced cementum was of the acellular extrinsic fibre type (AEFC) and reattachment was achieved with the principal periodontal ligament (PDL) fibres orientated almost perpendicular to the root surface. The initial interface formed between the old and new cementum, as well as the new AEFC, was characterized by a strong immunoreaction with OPN and collagen I antibody, but only a weak immunoreaction with the fibronectin antibody. Only a small number of mononuclear cells, which were involved in the repair process, showed a positive immunoreaction with the osteoblastic lineage markers runt-related transcription factor 2 and osteocalcin. These same cells stained sparsely with muscle segment homeobox homologue 2, but not with the E11 antibody. Thus, most of the cells associated with this reparative activity on the surface of the lacunae were differentiated PDL cells of the fibroblastic phenotype. Cells with a defined osteoblastic phenotype seemed to be of minor importance in this repair process.
本研究的目的是调查细胞外基质成分，如I型胶原、纤连蛋白和骨桥蛋白（OPN）在实验性诱导牙齿移动后牙骨质修复过程中的作用，并对参与再生过程的细胞进行特征描述。使用0.5N的螺旋弹簧使21只3个月大的雄性Wistar大鼠的右上第一磨牙向近中移动。9天后，移除矫治器，在撤力后立即将动物按每组3只处死，并在撤力后5、7、10、12、14和17天处死。3只大鼠作为非实验对照动物。制备上颌骨并进行组织学分析。随着多核破牙细胞从吸收陷窝中消失，正畸力释放5天后可见修复迹象。牙骨质修复的最初迹象在第10天出现。新形成的牙骨质为无细胞外源性纤维型（AEFC），重新附着是通过几乎垂直于根面排列的主要牙周膜（PDL）纤维实现的。新旧牙骨质以及新的AEFC之间形成的初始界面，其特征是与OPN和I型胶原抗体有强烈免疫反应，但与纤连蛋白抗体只有微弱免疫反应。只有少数参与修复过程的单核细胞与成骨细胞谱系标志物 runt相关转录因子2和骨钙素呈阳性免疫反应。这些相同的细胞用肌肉节段同源盒同源物2染色稀疏，但用E11抗体染色阴性。因此，与陷窝表面这种修复活性相关的大多数细胞是成纤维细胞表型的分化PDL细胞。具有明确成骨细胞表型的细胞在这个修复过程中似乎不太重要。
