Inoue T, Shimono M
Department of Pathology, Tokyo Dental College, Chiba, Japan.
Proc Finn Dent Soc. 1992;88 Suppl 1:183-94.
The purpose of this study was to investigate the dentinogenesis of dental pulp tissue following transplantation and during regeneration in normal and germ free animals, as well as in vitro experiments.
(1) Partial and complete exposure of dental pulp in germ free rats by removing the enamel and dentin of molars. (2) The central portion of rat incisor which consisted of pulp and pulp chamber were autografted into various tissues. (3) Explants of rat pulp tissue were cultured on dentin matrix. (4) Resin bonding agent, 4-META/MMA-TBB-O (Superbond), was placed directly on surgically-exposed dental pulp.
(1) Dentin bridge formation was recognized at 5 days after operation in germ free rat. (2) The cut surface of the transplant exhibited dentin bridge at 7 days after implantation, and the thickness of the newly formed dentin increased gradually thereafter up to 30 days. (3) Cultured pulp cells had high alkaline phosphatase activity and bone- or dentin-like hard tissue was synthesized on the dentin matrix in vitro. (4) Dentin bridge formation was evident on the surgically-exposed dental pulp even after application of Superbond. From these results, it is suggested that pulp tissue has a high activity of dentinogenesis both in vivo and in vitro and 3 days is enough for pulp cells to express the odontoblast phenotype when inflammatory factors are not present.
本研究的目的是调查正常动物和无菌动物移植及再生过程中牙髓组织的牙本质形成情况，以及进行体外实验。
（1）通过去除无菌大鼠磨牙的釉质和牙本质，使牙髓部分和完全暴露。（2）将大鼠切牙由牙髓和髓腔组成的中央部分自体移植到各种组织中。（3）将大鼠牙髓组织外植体培养在牙本质基质上。（4）将树脂粘结剂4-META/MMA-TBB-O（超级粘结剂）直接放置在手术暴露的牙髓上。
（1）无菌大鼠术后5天可见牙本质桥形成。（2）移植组织的切面在植入后7天出现牙本质桥，此后新形成的牙本质厚度逐渐增加，直至30天。（3）培养的牙髓细胞具有高碱性磷酸酶活性，并且在体外牙本质基质上合成了骨样或牙本质样硬组织。（4）即使应用了超级粘结剂，手术暴露的牙髓上也明显形成了牙本质桥。从这些结果表明，牙髓组织在体内和体外均具有较高的牙本质形成活性，并且在不存在炎症因子时，牙髓细胞表达成牙本质细胞表型3天就足够了。
