结缔组织生长因子盖髓剂对牙髓组织形态学的影响及其意义

目的: 研究大鼠牙髓机械损伤经结缔组织生长因子(CTGF/CCN2)覆盖于损伤牙髓处后不同时间点大鼠牙髓的组织形态学变化,阐明其作用机制。方法: 选择20只Wistar大鼠,平均分为5组,随机选取一组为正常组(不做任何处理),其余4组(3、7、14和28 d组)每只大鼠在双侧上颌第一磨牙备洞,左侧为CCN2盖髓剂的实验组,右侧为PBS对照组。分别于3、7、14和28 d处死大鼠并取其牙齿标本,经固定、脱钙、切片和HE染色,观察各标本中牙髓组织的形态学变化。结果: 对照组大鼠3 和7 d时穿髓孔下方炎症较实验组明显;14 d时炎症反应减轻,有散在的修复性牙本质形成;28 d时形成坏死病灶。实验组大鼠3 d时穿髓孔下方聚集大量炎细胞,血管扩张明显;7 d时炎症减轻,淋巴细胞相对于对照组少;14 d时已无明显炎细胞存在,并形成连续完整的钙化桥;28 d时形成大量修复性牙本质。结论: 牙髓组织损伤后,CCN2参与了组织结构的重建,提示CCN2是一种良好的盖髓剂。

Influence of capping agent CCN2 in morphology of dental pulp tissue

Objective To observe the histomorphological changes of dental pulp of the rats with mechanical injury at different time points after treated with connective tissue growth factor(CTGF/CCN2) and to clarify its mechanism. Methods Tweenty Wistar rats were divided into five groups, one group was randomly selected as normal group, each Wistar rat in the other four groups(groups of 3 d, 7 d, 14 d and 28 d) was prepared with a cavity on the occlusal surface of maxillary first molars on both sides. CCN2 was applied on the left exposed pulp for the PBS experimental group, and PBS was applied on the right exposed pulp for the control group.Four rats, one in each group, were put to death respectively on the 3rd, 7th, 14th and 28th day after operation.The teeth of each rat were fixed, decalcified and made to sections, which were stained with HE.The histomorphological changes of dental pulp tissue in each sample were observed. Results In control group, the inflammation under the amputated site was more obvious than the experimental group at 3 d and 7 d;the inflammatory cells were decreased and scattered reparative dentin was observed in 14 d;necrosis was observed at 28 d.While in experimental group a large number of inflammatory cells gathered under the amputated site at 3 d, as well as the dilatation of blood vessels was observed;7 d after injury the inflammation in experimental group was reduced.Compared with control group, the leukomonocytes were less.After injury for 14 d the calcified bridge was observed and the inflammatory cells disappeared;28 d after injury the reparative dentin was observed. Conclusion CCN2 participates in the reconstruction of the tissue structure after dental pulp injury.It indicates that CCN2 is a good pulp capping agent.