Nassar Mohannad, Dargham Ahmad, Jamleh Ahmed, Tamura Yukihiko, Hiraishi Noriko, Tagami Junji
Department of Preventive and Restorative Dentistry, College of Dental Medicine, University of Sharjah, Sharjah, United Arab Emirates.
Ras Al Khaimah College of Dental Sciences, Ras Al Khaimah Medical and Health Sciences University, Ras Al Khaimah, United Arab Emirates.
Eur J Dent. 2021 May;15(2):222-227. doi: 10.1055/s-0040-1718637. Epub 2020 Oct 30.
Despite the agreement that there is no longer any indication for arsenic use in modern endodontics, some concerns are surfacing about the minute amount of arsenic trioxide (AsO) released from Portland cement-based materials. The present study investigated the effect of different concentrations of AsO on rat pulpal cells and the efficacy of -acetylcysteine (NAC) in preventing AsO-mediated toxicity.
Cytotoxicities of 50, 10, or 5 µm AsO and the effect of cells co-treatment with 50 µm AsO and 5,000 µm NAC or 500 µm NAC were tested at 24 hours or 3 days. Cell viability was assessed by means of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and cellular morphological changes were observed under phase contrast microscope.
Two-way analysis of variance with Tukey's post-hoc test was used to evaluate differences between the groups (α = 0.05).
At both exposure times, 50 µm AsO resulted in lower optical density (OD) values when compared with 10 or 5 µm AsO. At 24 hours, 10 µm AsO resulted in a higher OD value compared with the control; however, at 3 days the difference was statistically insignificant. At each exposure time, the OD value of 5 µm AsO group was comparable to the control and 10 µm AsO group. There were no significant differences between 50 µm AsO group and 500 μm NAC+50 μm AsO group; however, these two groups had lower OD values when compared with 5,000 μm NAC+50 μm AsO group at 24 hours and 3 days. The latter group showed significantly lower OD value in comparison with the control at 24 hours and 3 days. Control cells were polygonal-shaped while 50 µm AsO-treated cells exhibited contracted and spherical morphology with increased intercellular spaces. At 24 hours, 10 μm and 5 µm AsO-treated cells were slightly hypertrophic. Cells co-treated with NAC and AsO showed increased intercellular spaces and lower cellular density compared with the control.
AsO displayed a hormetic effect on pulpal cells; however, the proliferative effect induced by low AsO concentrations should be interpreted with caution. NAC did not prevent AsO-mediated toxicity; however, it demonstrated potential for ameliorating this toxicity.
尽管人们一致认为现代牙髓病学中已不再有使用砷的指征，但对于波特兰水泥基材料释放的微量三氧化二砷（AsO）仍存在一些担忧。本研究调查了不同浓度的AsO对大鼠牙髓细胞的影响以及N - 乙酰半胱氨酸（NAC）预防AsO介导毒性的效果。
在24小时或3天时测试50、10或5μm AsO的细胞毒性以及50μm AsO与5000μm NAC或500μm NAC联合处理细胞的效果。通过MTT（3 -（4,5 - 二甲基噻唑 - 2 - 基）- 2,5 - 二苯基四氮唑溴盐）法评估细胞活力，并在相差显微镜下观察细胞形态变化。
采用双向方差分析及Tukey事后检验评估组间差异（α = 0.05）。
在两个暴露时间点，与10或5μm AsO相比，50μm AsO导致较低的光密度（OD）值 24小时时，与对照组相比，10μm AsO导致较高的OD值；然而，在3天时差异无统计学意义。在每个暴露时间点，5μm AsO组的OD值与对照组和10μm AsO组相当。50μm AsO组与500μm NAC + 50μm AsO组之间无显著差异；然而,在24小时和3天时，这两组与5000μm NAC + 50μm AsO组相比OD值较低。后一组在24小时和3天时与对照组相比OD值显著降低。对照细胞呈多边形，而50μm AsO处理的细胞表现出收缩的球形形态，细胞间隙增加。24小时时，10μm和5μm AsO处理的细胞略有肥大。与NAC和AsO联合处理的细胞与对照组相比，细胞间隙增加，细胞密度降低。
AsO对牙髓细胞显示出 hormetic效应；然而，低浓度AsO诱导的增殖效应应谨慎解读。NAC不能预防AsO介导的毒性；然而，它显示出改善这种毒性的潜力。
