Department of Pathology, Tokyo Dental College, Mihama-ku, Chiba, Japan.
Oral Dis. 2010 Apr;16(3):263-8. doi: 10.1111/j.1601-0825.2009.01594.x. Epub 2009 Oct 29.
The aim of this study was to investigate the proliferation, migration and death of periodontal ligament (PDL) cells after tooth replantation.
Maxillary first molars were extracted from 4-week-old male (n = 28) Sprague-Dawley rats and immediately replanted, after which, proliferation, migration and death of PDL cells were investigated.
At 3 days after tooth replantation, many proliferative cell nuclear antigen (PCNA)-positive PDL cells were observed on the alveolar bone side, but fewer on the root side. However, while a gradual decrease was observed in number of PCNA-positive PDL cells on the alveolar bone side until 7 days, an increase was seen on the root side. At 3 weeks, cells labeled with PKH26 (fluorescent dye into plasma membrane) were located in the middle of the PDL space. However, these PKH26-labeled cells did not spread to the surface of the cementum or the alveolar bone. TUNEL-positive cells were observed on both the bone and root sides at 3 days. Number of apoptotic cells increased until 7 days on the bone sides, but decreased on root sides.
These results suggest that both cell proliferation and apoptosis occur in different patterns and at different times to maintain regular spacing of the PDL after tooth replantation.
本研究旨在探讨牙再植后牙周膜（PDL）细胞的增殖、迁移和死亡。
从 4 周龄雄性 Sprague-Dawley 大鼠中提取上颌第一磨牙并立即进行再植，然后研究 PDL 细胞的增殖、迁移和死亡。
牙再植后 3 天，在牙槽骨侧观察到许多增殖细胞核抗原（PCNA）阳性的 PDL 细胞，但在根侧则较少。然而，虽然牙槽骨侧的 PCNA 阳性 PDL 细胞数量逐渐减少直到第 7 天，但在根侧则增加。3 周时，PKH26（荧光染料进入质膜）标记的细胞位于 PDL 空间的中间。然而，这些 PKH26 标记的细胞并未扩散到牙骨质或牙槽骨表面。3 天时在骨侧和根侧均观察到 TUNEL 阳性细胞。骨侧的凋亡细胞数量增加到第 7 天，但根侧减少。
这些结果表明，在牙再植后，为了维持 PDL 的正常间隔，细胞增殖和凋亡以不同的模式和时间发生。
