Department of Preventive and Restorative Dentistry, College of Dental Medicine, University of Sharjah, Sharjah, United Arab Emirates.
RAK College of Dental Sciences (RAKCODS), RAK Medical and Health Sciences University (RAKMHSU), Ras Al Khaimah, United Arab Emirates.
Eur Endod J. 2020 Dec;5(3):277-281. doi: 10.14744/eej.2020.26878.
Despite the controversial results regarding the amount of arsenic (As) in mineral trioxide aggregate (MTA) and MTA-like cements, it is prudent to assess the effect of this heavy metal on pulpal cells and search for methods to attenuate its toxicity. This study investigated the toxic effect of As on pulpal-like cells and evaluated the influence of reduced glutathione (GSH) on As-induced toxicity.
The cytotoxicity of 50 µm As, 50 µm As+50 µM GSH, 50µm As+500 µM GSH or 50 µm As+5000 µM GSH on rat pulpal cells (RPC-C2A) was evaluated at 24 hours and 72 hours. Cell culture in fresh medium without experimental solution served as the control. Cell viability was measured by means of 3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide (MTT) assay and the optical density was measured with microplate reader. The morphology of the cultured cells was observed under phase contrast microscope. Cytotoxicity data were analyzed by two-way ANOVA and Tukey post hoc tests (P<0.05).
There were statistically significant differences in cell viability amongst the tested groups (P<0.05). As elicited remarkable toxic effect on pulpal cells, while 5000 µM GSH protected the cells from As-induced damage at 24-hour exposure time. The cultured control cells were polygonal-shaped; however, As-treated cells exhibited contracted and spherical morphology with increased intercellular spaces indicative of cellular death and decreased proliferation.
As negatively affected the viability of pulpal cells; however, controlled concentration of GSH had a short-term protective effect against As-induced toxicity. Future research is warranted on the clinical use of GSH with MTA and MTA-like cements to minimize initial inflammation resulting from As release during the setting of the aforementioned cements thus enhancing the success of procedures where these cements are placed in direct contact with vital pulp tissues.
尽管关于矿化三氧化物凝聚体（MTA）和 MTA 类水泥中砷（As）含量存在争议，但评估这种重金属对牙髓细胞的影响并寻找减轻其毒性的方法是谨慎的。本研究调查了 As 对牙髓样细胞的毒性作用，并评估了还原型谷胱甘肽（GSH）对 As 诱导毒性的影响。
在 24 小时和 72 小时时，评估 50µm As、50µm As+50µM GSH、50µm As+500µM GSH 或 50µm As+5000µM GSH 对大鼠牙髓细胞（RPC-C2A）的细胞毒性。不含实验溶液的新鲜培养基中的细胞培养作为对照。通过 3-(4.5-二甲基噻唑-2-基)-2.5-二苯基四氮唑溴盐（MTT）测定法测量细胞活力，并使用微孔板阅读器测量吸光度。在相差显微镜下观察培养细胞的形态。通过双因素方差分析和 Tukey 事后检验（P<0.05）分析细胞毒性数据。
在测试组之间，细胞活力存在统计学上的显著差异（P<0.05）。As 对牙髓细胞产生了显著的毒性作用，而在 24 小时暴露时间内，5000µM GSH 保护细胞免受 As 诱导的损伤。培养的对照细胞呈多边形；然而，As 处理的细胞表现出收缩和球形形态，细胞间空间增加，表明细胞死亡和增殖减少。
As 对牙髓细胞的活力产生了负面影响；然而，控制浓度的 GSH 对 As 诱导的毒性具有短期保护作用。需要对 GSH 与 MTA 和 MTA 类水泥的临床应用进行进一步研究，以最大限度地减少上述水泥凝固过程中 As 释放引起的初始炎症，从而提高这些水泥直接接触活髓组织的手术成功率。
