CU Dental Innovation Center, Faculty of Dentistry, Chulalongkorn University, Henri-Dunant 34, 10330 Bangkok, Thailand.
Department of Operative/Restorative Dentistry, Periodontology and Pedodontics, Ludwig-Maximilians-University of Munich, Goethestr 70, 80336 Munich, Germany; Walther-Straub-Institute of Pharmacology and Toxicology, Ludwig-Maximilians-University of Munich, Nussbaumstr 26, 80336 Munich, Germany.
Dent Mater. 2018 Feb;34(2):282-287. doi: 10.1016/j.dental.2017.11.011. Epub 2017 Nov 27.
(1) To investigate the genotoxicity of a glass ionomer cement (GIC) and GIC incorporated with titanium dioxide nanopoarticle (TiONPs) and with microparticle (TiOMPs) on DNA double-strand breaks of human gingival fibroblast cells (HGFs). (2) To compare the genotoxic differences between GIC and two modified cements.
TiONPsGIC and TiOMPsGIC were prepared by adding 10% w/w of TiONPs and TiOMPs to the GIC powder and hand-mixed followed the manufacturer instruction. Dulbecco's Minimum Essential Medium (DMEM) was used as a culture medium for HGFs and eluate preparation. Eluates from all groups were collected for XTT cell viability assay to obtain EC values. γ-H2AX immunofluorescence assay was performed to detect DNA double-strand breaks (DSBs) of HGFs.
EC values were from 38% to 60% and eluate concentrations at 20% and 5% were selected for γ-H2AX immunofluorescence assay. At both concentrations, HGFs exposed to eluates from all cements groups had fewer mean foci per cell and higher percentage of free foci cells than HO (p<0.05). At 20% concentration, cells exposed to eluates from both TiONPsGIC and TiOMPsGIC groups had fewer mean foci per cell and higher percentage of free foci cell than GIC and culture medium (p<0.05).
Neither GIC nor 10% TiO-modified GICs had a genotoxic effect on HGFs. Both TiONPsGIC and TiOMPsGIC demonstrated less genotoxic effect than GIC. When comparing between the two modified cements, there was no genotoxic difference between the modified cements from different particle sizes (nanoparticle and micro-particle) of TiO.
(1) 研究玻璃离子水门汀（GIC）以及掺入二氧化钛纳米粒子（TiONPs）和微米粒子（TiOMPs）的 GIC 对人牙龈成纤维细胞（HGFs）DNA 双链断裂的遗传毒性。(2) 比较 GIC 与两种改良水门汀之间的遗传毒性差异。
通过将 10wt%的 TiONPs 和 TiOMPs 加入到 GIC 粉末中并按照制造商的说明进行手工混合，制备 TiONPsGIC 和 TiOMPsGIC。 Dulbecco's 最低必需培养基（DMEM）用作 HGFs 的培养基和浸提液制备。收集所有组别的浸提液进行 XTT 细胞活力测定以获得 EC 值。通过γ-H2AX 免疫荧光法检测 HGFs 的 DNA 双链断裂（DSBs）。
EC 值在 38%至 60%之间，选择 20%和 5%的浸提液浓度进行γ-H2AX 免疫荧光法。在这两个浓度下，与 HO 相比，暴露于所有水门汀组浸提液的 HGFs 每个细胞的平均焦点数量更少，游离焦点细胞的比例更高（p<0.05）。在 20%的浓度下，暴露于 TiONPsGIC 和 TiOMPsGIC 组浸提液的细胞每个细胞的平均焦点数量更少，游离焦点细胞的比例更高，与 GIC 和培养基相比（p<0.05）。
GIC 或 10%TiO 改性 GIC 对 HGFs 均无遗传毒性。TiONPsGIC 和 TiOMPsGIC 均表现出比 GIC 更小的遗传毒性作用。在比较两种改性水门汀时，TiO 的两种不同粒径（纳米粒子和微米粒子）的改性水门汀之间没有遗传毒性差异。
