Yang J, Wang W J, Jia W Q, Zhao Y M, Ge L H
Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology & National Clinical Research Center for Oral Diseases & National Engineering Laboratory for Digital and Material Technology of Stomatology & Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China.
Zhonghua Kou Qiang Yi Xue Za Zhi. 2018 Jul 9;53(7):459-465. doi: 10.3760/cma.j.issn.1002-0098.2018.07.006.
To evaluate the effect of exogenous stem cells from apical papillae (SCAP) in the pulp revascularization treatment for the immature permanent tooth with periapical periodontitis in animal model. After the SCAP were isolated and cultured from the Beagle dogs, stem cell properties of these cells were characterized by analyzing their colony-forming ability, the expression of mesenchymal stem cell markers and the multidifferentiation characteristics including osteogenic, adipogenic, and chondrogenic potentials. Models of young permanent tooth with periapical periodontitis were established in dogs and the infection in each of the model tooth was eliminated by root canal irrigation and intracanal medication. After that, all of the model teeth were randomly divided into 4 groups: Group 1: normal developing teeth with no treatment applied;Group 2: teeth that periapical tissues were irritated to induce blood flowing into the root canals;Group 3: teeth that peripheral blood was delivered into the root canals;Group 4: teeth that SCAP were resuspended in peripheral blood and delivered into the root canals. In Group 2-4, firm coronal seal was performed after revascularization procedure and radiographs were taken periodically in order to observe the development of roots. After a 12-week-period, alveolar samples were collected and observed histologically. The isolated SCAP showed clonogenic ability and multilineage differentiation ability including osteogenic, adipogenic and chondrogenic potentials. These cells also expressed the mesenchymal stem cell markers such as STRO-1 and CD146, while no cytokeratin was detected. The thickening of canal wall was observed radiographically 12 weeks after procedures of infection control and revascularization. Histologically, the newly formed tissues on the inner canal wall were found bone lacuna like structure in Group 2 and 3, and the new tissue formed in the Group 3 seemed easy to separate from the canal wall. The newly formed tissues in Group 4 were much thicker compare to those in the Group 2 and 3, and the dentine tubule like structure instead of bone lacuna was noticed although the orientation of these tubules were various. SCAP seem to play an important role in the tissue regeneration procedure when infection is well controlled in young permanent teeth with periapical periodontitis. It is difficult to achieve real tissue regeneration due to the lack of endogenous SCAP in apical area, therefore delivering adequate exogenous SCAP isolated and cultured in vitro could be a promising approach to overcome the challenge.
评估根尖乳头外源性干细胞（SCAP）在动物模型中对患有根尖周炎的未成熟恒牙进行牙髓血运重建治疗的效果。从小猎犬中分离并培养SCAP后，通过分析其集落形成能力、间充质干细胞标志物的表达以及包括成骨、成脂和成软骨潜能在内的多分化特性来表征这些细胞的干细胞特性。在犬类中建立年轻恒牙根尖周炎模型，并通过根管冲洗和根管内用药消除每个模型牙中的感染。之后，将所有模型牙随机分为4组：第1组：未进行治疗的正常发育牙齿；第2组：刺激根尖周组织以诱导血液流入根管的牙齿；第3组：将外周血注入根管的牙齿；第4组：将悬浮在外周血中的SCAP注入根管的牙齿。在第2 - 4组中，血运重建术后进行牢固的冠部封闭，并定期拍摄X线片以观察牙根的发育情况。12周后，收集牙槽骨样本并进行组织学观察。分离出的SCAP表现出克隆形成能力和多谱系分化能力，包括成骨、成脂和成软骨潜能。这些细胞还表达了间充质干细胞标志物，如STRO - 1和CD146，而未检测到细胞角蛋白。在感染控制和血运重建术后12周，X线片观察到根管壁增厚。组织学上，第2组和第3组在内根管壁上发现新形成的组织有骨陷窝样结构，第3组中形成的新组织似乎易于与根管壁分离。第4组中形成的新组织比第2组和第3组厚得多，尽管这些小管的方向各不相同，但观察到的是牙本质小管样结构而非骨陷窝。当患有根尖周炎的年轻恒牙感染得到良好控制时，SCAP似乎在组织再生过程中发挥重要作用。由于根尖区域缺乏内源性SCAP，难以实现真正的组织再生，因此输送体外分离和培养的足够外源性SCAP可能是克服这一挑战的一种有前景的方法。
