Department of Dental and Biomedical Material Sciences, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan.
J Endod. 2013 Jul;39(7):883-8. doi: 10.1016/j.joen.2013.03.003. Epub 2013 Apr 3.
CPoint is a polymeric endodontic point that takes advantage of water-induced, non-isotropic radial expansion to adapt to canal irregularities. This study evaluated the effects of CPoint on the viability and mineralization potential of odontoblast-like cells.
The biocompatibility of CPoint and commercially available gutta-percha points was evaluated by using a rat odontoblast-like cell line (MDPC-23). Cell viability was evaluated with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, flow cytometry, and confocal laser scanning microscopy. The mineralization potential of MDPC-23 cells, in the presence of the root-filling materials, was evaluated by examining the changes in osteogenic gene marker expression (quantitative real-time polymerase chain reaction), alkaline phosphatase activity, alizarin red S assay, and transmission electron microscopy.
CPoint showed higher initial cytotoxicity compared with gutta-percha and Teflon (P < .05), which became nonsignificant after 4 immersion cycles. Significant differences were also found between eluents from CPoint and gutta-percha at 1:1 concentration (P < .05) but not at 1:10 or 1:100 concentration. Both materials induced minimal apoptosis-induced alteration in plasma membrane permeability, as evidenced by flow cytometry and confocal laser scanning microscopy. Compared with the Teflon negative control, CPoint and gutta-percha groups showed up-regulation of most osteogenic gene markers except for dentin sialophosphoprotein, which was down-regulated. Alkaline phosphatase activity and alizarin red assay for CPoint and gutta-percha were both significantly higher than for Teflon but not significantly different from each other (P > .05). Transmission electron microscopy showed discrete nodular electron-dense mineralization foci in all 3 groups.
The in vitro biocompatibility of CPoint is comparable to gutta-percha with minimal adverse effects on osteogenesis after elution of potentially toxic components.
CPoint 是一种聚合根管尖端，它利用水诱导的非各向同性径向膨胀来适应根管不规则性。本研究评估了 CPoint 对成牙本质细胞样细胞活力和矿化潜能的影响。
通过使用大鼠成牙本质细胞样细胞系（MDPC-23）评估 CPoint 和市售牙胶尖的生物相容性。通过 3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐法、流式细胞术和共聚焦激光扫描显微镜评估细胞活力。通过检测成骨基因标志物表达（定量实时聚合酶链反应）、碱性磷酸酶活性、茜素红 S 检测和透射电子显微镜的变化，评估 MDPC-23 细胞在根充材料存在下的矿化潜能。
CPoint 与牙胶和聚四氟乙烯（Teflon）相比表现出更高的初始细胞毒性（P <.05），但在 4 次浸泡循环后变得无统计学意义。在 1:1 浓度下，CPoint 和牙胶的洗脱液之间也存在显著差异（P <.05），但在 1:10 或 1:100 浓度下没有差异。两种材料都引起了细胞膜通透性的最小的凋亡诱导改变，这一点通过流式细胞术和共聚焦激光扫描显微镜得到了证实。与 Teflon 阴性对照组相比，CPoint 和牙胶组除牙本质涎磷蛋白下调外，大多数成骨基因标志物均上调。CPoint 和牙胶的碱性磷酸酶活性和茜素红检测均显著高于 Teflon，但彼此之间无显著差异（P >.05）。透射电子显微镜显示，所有 3 组均有离散的结节状电子致密矿化焦点。
CPoint 的体外生物相容性与牙胶相当，在洗脱潜在毒性成分后对成骨的影响最小。
