In Vitro Cytotoxicity of White MTA, MTA Fillapex® and Portland Cement on Human Periodontal Ligament Fibroblasts

The aim of this study was to compare the in vitro cytotoxicity of white mineral trioxide aggregate (MTA), MTA Fillapex® and Portland cement (PC) on human cultured periodontal ligament fibroblasts. Periodontal ligament fibroblast culture was established and the cells were used for cytotoxic tests after the fourth passage. Cell density was set at 1.25 X10 4 cells/well in 96-well plates. Endodontic material extracts were prepared by placing sealer/cement specimens (5X3mm) in 1mL of culture medium for 72 h. The extracts were then serially two-fold diluted and inserted into the cell-seeded wells for 24, 48 and 72 h. MTT assay was employed for analysis of cell viability. Cell supernatants were tested for nitric oxide using the Griess reagent system. MTA presented cytotoxic effect in undiluted extracts at 24 and 72 h. MTA Fillapex® presented the highest cytotoxic levels with important cell viability reduction for pure extracts and at ½ and ¼ dilutions. In this study, PC did not induce alterations in fibroblast viability. Nitric oxide was detected in extract-treated cell supernatants and also in the extracts only, suggesting presence of nitrite in the soluble content of the tested materials. In the present study, MTA Fillapex displayed the highest cytotoxic effect on periodontal ligament fibroblasts followed by white MTA and PC.

本研究旨在比较白色三氧化矿物凝聚体（white mineral trioxide aggregate, MTA）、MTA Fillapex®与硅酸盐水泥（Portland cement, PC）对人类体外培养牙周膜成纤维细胞的体外细胞毒性。本研究建立了牙周膜成纤维细胞培养体系，于第4代传代后将细胞用于细胞毒性实验。以1.25×10⁴ 个细胞/孔的密度将细胞接种于96孔板中。牙髓材料浸提液的制备方法为：将封闭剂/水门汀试件（5mm×3mm）置于1mL培养液中浸泡72小时。随后将浸提液进行连续两倍稀释，加入铺有细胞的培养孔中，分别孵育24、48及72小时。采用MTT法检测细胞活力。使用格里斯试剂系统检测细胞上清液中的一氧化氮含量。结果显示，MTA在未稀释浸提液中于24小时和72小时时表现出细胞毒性。MTA Fillapex®的细胞毒性水平最高，纯浸提液以及1/2、1/4稀释液均可显著降低细胞活力。本研究中，硅酸盐水泥未对成纤维细胞活力产生显著影响。在经浸提液处理的细胞上清液及单独的浸提液中均检测到一氧化氮，提示受试材料的可溶性成分中含有亚硝酸盐。综上，本研究中MTA Fillapex对牙周膜成纤维细胞的细胞毒性最强，其次为白色MTA与硅酸盐水泥。