Magloire H, Joffre A, Bleicher F
Laboratoire du Developpement des Tissus Dentaires, Faculté d'Odontologie, Lyon, France.
J Dent Res. 1996 Dec;75(12):1971-8. doi: 10.1177/00220345960750120901.
Pulp tissue responds to dentin injury by laying down reactionary dentin secreted by existing odontoblasts or reparative dentin elaborated by odontoblast-like cells that differentiated from precursor cells in the absence of inner dental epithelium and basement membrane. Furthermore, growth factors or active dentin matrix components are fundamental signals involved in odontoblast differentiation. In vitro, dental pulp cells cultured under various conditions are able to express typical markers of differentiation, but no culture system can re-create pulp response to dentin drilling. This paper reports the behavior of thick slices from human teeth drilled immediately after extraction and cultured from 3 days to 1 month. Results show that the damaged pulp beneath the cavity is able to develop, in vitro, some typical aspects correlated to tissue healing, evidenced by cell proliferation (BrdU-positive cells), neovascularization (positive with antitype-IV collagen antibodies), and the presence of functional (3H proline-positive) cuboidal cells close to the injured area. After 30 days of culture, elongated spindle-shaped cells can be seen aligned along the edges of the relevant dentin walls, whereas sound functional odontoblasts are well-preserved beneath healthy areas. This tissue recovery leads us to believe that such a culture model will be a useful system for testing factors regulating pulp repair.
牙髓组织通过沉积由现有成牙本质细胞分泌的反应性牙本质或由在无内釉上皮和基底膜情况下从前体细胞分化而来的成牙本质样细胞形成的修复性牙本质来应对牙本质损伤。此外，生长因子或活性牙本质基质成分是参与成牙本质细胞分化的基本信号。在体外，在各种条件下培养的牙髓细胞能够表达典型的分化标志物，但没有培养系统能够重现牙髓对牙本质钻孔的反应。本文报道了人牙在拔除后立即钻孔并培养3天至1个月的厚切片的行为。结果表明，龋洞下方受损的牙髓在体外能够出现一些与组织愈合相关的典型表现，细胞增殖（BrdU阳性细胞）、新血管形成（抗IV型胶原抗体阳性）以及在损伤区域附近存在功能性（3H脯氨酸阳性）立方体细胞可证明这一点。培养30天后，可以看到细长的梭形细胞沿相关牙本质壁的边缘排列，而健康区域下方的健全功能性成牙本质细胞保存良好。这种组织恢复使我们相信，这样的培养模型将是测试调节牙髓修复因子的有用系统。
