人牙髓中MMP-2与MMP-9受正畸力作用影响的初步分析

目的：采用免疫组织化学方法,研究接受正畸力作用影响的人牙髓中MMP-2和MMP-9的表达。方法：选取接受正畸治疗的患者10名,于正畸治疗前确定应拔除的正畸牙,对其一侧选用常规正畸加力,另一侧健康同名牙不施加任何正畸力,作为同源对照,加力1d后至7d内拔除该正畸牙,各20颗,共40颗,分为加力组和对照组;选取临床诊断有牙髓炎症且无保留价值的第3磨牙20例,分为炎症组;对标本进行处理后制成切片,采用SP法,对其中MMP-2和MMP-9的表达进行图像分析和半定量分析。结果：对照组、加力组和炎症组牙髓均可见MMP-2和MMP-9的表达;在接受正畸力的牙髓组织,成牙本质细胞和牙髓成纤维细胞可见MMP-2和MMP-9表达,加力组牙髓中两者为表达增强,并且其表达强于同源对照正常的牙髓,但弱于炎症牙髓,三组差异具有统计学意义（P〈0.05）。结论：MMP-2和MMP-9在人牙髓中主要表达于成牙本质细胞和牙髓成纤维细胞的胞质中;生理条件下两者的水平较低,在接受正畸治疗时,由于受正畸力影响,牙髓处于应激状态,两者表达增强,应引起口腔医师的高度重视。

The expressions of MMP-2 and MMP-9 in human dental pulps under the effects of orthodontic Forces

Objective：To Study the expressions of MMP-2 and MMP-9 in human dental pulps in patients under the effects of orthodontic forces.Methods：10 orthodontic patients were selected,the orthodontic teeth to be extracted were decided before orthodontic treatments had started.One side of the orthoodontic tooth underwent routine orthodontic forces.The teeth were extracted within 1 to 7days after orthodontic forces had been used.There were 20 teeth as under-forces group.The other side of the pre-extracted teeth did not receive any orthodontic forces.There are also 20 teeth as homologized control group.20 third molares clinically diagnosed with endodontitis and without worth of remaining were as inflamed group.Iimmunohistochemical streptavidin peroxidase method（SP method）was used.The expressions of MMP-2 and MMP-9 were analyzed by analysing images and half-quantitative analysis.Results：There were expressions of MMP-2 and MMP-9 in control,under-forces and inflamed groups.In under-forces pulpal tissues,MMP-2 and MMP-9 were mainly expressed in odontoblasts and fibroblasts.In under-forces pulps,the expression of MMP-2 and MMP-9 were manifestly stronger than that of controls,but weaker than that of the inflamed one.The differences among the three groups had statistical significance（P〈0.05）.Conclusions：MMP-2 and MMP-9 are mainly expressed in cytoplasts of odontoblasts and fibroblasts in human dental pulps.In physiological conditions,the expression levels of MMP-2 and MMP-9 are low.During orthodontic treatments,effected by the orthodontic forces,the dental pulps are in stringent state.The expressions of MMP-2 and MMP-9 are strengthened which should arouse the attention of the dentists.