小鼠下颌第一磨牙根尖周炎及牙髓血运重建模型的建立

摘要

目的：建立小鼠下颌第一磨牙根尖周炎及去髓后血运重建模型。方法：20只小鼠左侧下颌第一磨牙行牙髓摘除术后进行牙髓血运重建处理；右侧下颌第一磨牙髓腔开放形成实验性根尖周炎；另取10只小鼠未处理磨牙作为空白对照。术后3周进行影像学、组织学及 qRT －PCR 分析。结果：牙髓血运重建组表现为根管腔缩窄，根尖部膨大，管腔内有血管化的新生组织长入，根尖部有骨样和软骨样组织沉积，血管内皮生长因子（VEGF）的表达显著高于对照组（P ＜0．05）。根尖周炎组可观察到根尖周骨质破坏，根管内含大量坏死物质，根尖周慢性炎症细胞浸润，IL －1β、IL －6、TNF －α的表达显著高于对照组（P ＜0．05）。结论：成功建立小鼠下颌第一磨牙根尖周炎及去髓后血运重建模型。%AIM:To establish an experimental animal model of apical periodontitis and pulp revasculariza-tion in mice.METHODS:The left first mandibular molars of 3 -week C57BL/6 mice underwent pulpectomy,then received pulp revascularization treatment(group PR).While the dental pulp cavity of the right first mandibular molars were exposed to the oral environment(group AP).Untreated normal teeth were served as the blank controls.Animals were killed 3 weeks after surgery for radiographical,histological and qRT -PCR examination.RESULTS:In PR group canal space was narrowed and hard tissue was found in root canal observed by Micro-CT.Histologic evaluation showed that in PR group the canal space was filled with connective tissue containing numerous blood vessels,and the apical portion of the root was full of calcification tissue and bone like tissues.VEGF expression was higher in PR group than that in the blank control group(P <0.05).In AP group,the root canal was filled with necrotic tissues.Apical le-sion was present and periapical portion had inflammatory cell infiltration,apical bone resorption was observed by Micro-CT.IL-1 β,IL-6,and TNF-αexpression was higher than that of the blank control group(P <0.05).CON-CLUSION:In this study,the animal models of experimental apical periodontitis and pulp revascularization in mice were established.