目的

通过观察大鼠正畸牙移动过程中牙周组织内的核因子κB（NF-κB）表达变化，探讨其在正畸牙移动过程中的作用机制。

方法

将56 只8 周龄体重（220 ± 25） g 雄性SD 大鼠根据正畸力加载时间不同（6 h、12 h、24 h、3 d、7 d、14 d、21 d）分为7 组，每组8 只。 随机选择一侧上颌第一磨牙作为实验牙，对侧第一磨牙作为自身对照牙，采用NiTi 拉簧建立大鼠正畸牙移动模型，力值为50 g，分别于相应时间点取正畸牙牙周组织，行免疫组织化学染色检测NF-κB 的表达。

结果

NF-κB 在对照侧大鼠牙周组织中弱表达；在正畸移动模型中，NF-κB 表达量从加力6 h 开始上升，至加力3、7 d 后达到峰值，之后逐渐下调，至加力21 d 仍稍高于对照牙，压力侧表达大于张力侧。

结论

NF-κB 参与正畸力作用下牙周组织早期的炎症反应和后期的组织改建过程，并且可能更多地参与了牙周改建的骨吸收过程，而对于成骨细胞的作用可能具有一定的相关性，但其具体机制有待进一步研究。

Objective

To explore the mechanism of periodontal remodeling by observing the expression of nuclear factor-kappa B （NF-κB） in the periodontium of rat molars during orthodontic tooth movement.

Methods

56 male SD rats， 8 weeks old and （220±25） g in weight were randomly divided into 6 h， 12 h， 24 h， 3 d， 7 d， 14 d， 21 d， and were loaded with 50 gram orthodontic force on one side of the maxillary first molar to detect the expression NF-κB immunohistochemically， the first molar on the other side were used as the nonappliance control.

Results

A weakly positive expression can be detected in the controlled groups； in the experimental groups， the concentration increased from 6 h，reaching to the peak at the 3rd day and 7th d， and then decreased until the 21st d， at that time， the positive expressions is still higher than that of the controlled side. The expression of the NF-κB in the pressed zone was higher than that that in the tension zone.

Conclusions

NF-κB may participate in the inflammatory reaction in the early stage and the reconstruction of the periodontal tissue in the late stage during orthodontic tooth movement of the rat molars. NF-κB may also plays a more important role in osteoclasts， while its role in bone formation needs further exploration.