Histlogical Examination of Periodontal Regeneration by Implantation of Cultured Periodontal Ligament Cell

以往的研究表明，培养和种植的牙周膜细胞具有牙周膜和牙骨质再生的潜力。但培养和植入的细胞的动力学方面和功能尚不清楚。本研究的目的是评估培养和植入的牙周膜细胞的动力学方面。实验组牙周膜细胞在最低基本培养液(MEM)中培养并标记于牙本质块上，辅以溴脱氧尿苷(BrdU)，植入同种异体大鼠颅骨缺损处。对照组植入未培养细胞的牙本质块。分别于植入后7、14、21、28天取材进行组织学检查。标本用组织树脂Plus制片，抗BrdU单抗免疫染色，碱性磷酸酶(ALP)和抗酒石酸酸性磷酸酶(TRAP)染色。对照组7d可见TRAP阳性细胞，14d可见TRAP阳性细胞和碱性磷酸酶阳性细胞。术后第14天可见关节僵硬，第21、28天强直程度有所加重。实验组第7天的结果与对照组相似。但在第14、21和28天，部分标本的牙本质块上可见细胞牙骨质样组织。BrdU阳性成纤维细胞样细胞、ALP阳性细胞和TRAP阳性细胞也在新形成的细胞牙骨质样组织周围检测到。这些结果表明，培养和植入的牙周膜细胞能够在植入后持续28d，可能与新的牙骨质样组织的形成和抑制强直有关。

In the previous study, it was suggested that the cultured and implanted periodontal ligament cell had the regenerative potential for the periodontal ligament and cementum. But the kinetic aspects and the function of the cultured and implanted cell were not cleared. The purpose of this study is to evaluate the kinetic aspects of cultured and implanted periodontal ligament cells. In the experimental group, periodontal ligament cells were cultured and labeled on the dentin blocks in Minimum Essential Medium (MEM), supplemented with bromodeoxyuridine (BrdU) and implanted on the syngeneic rats calvaria defects. In the control group, dentin blocks without cultured cells were implanted. The samples were prepared for histological examination on 7, 14, 21 and 28 daysafter implantation. Specimens were made with Historesin plus, immunostained with anti-BrdU monoclonal antibody, and stained for alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP). In the control group, on 7 day TRAP-positive cells were detected, and TRAP-positive and ALP -positive cells were observed on 14 day. Ankylosis was also observed on 14 day, which was advanced on 21 and 28 day. In the experimental group, results were similar to those of the control group on the 7 day. But on 14, 21and 28 day, cellular cementum-like tissue was observed on the dentin blocks in some of the specimens. BrdU positive fibroblast-like cells, ALP-positive cells and TRAP-positive cells were also detected around the newly formed cellular cementum-like tissue. These results suggest that the cultured and implanted periodontal ligament cells are able to persist up to 28 days after implantation, and may be concerned with the formation of new cementum-like tissue and inhibit ankylosis.