Egyptian Russian University, Faculty of Dentistry, Dental Biomaterials Department. Cairo, Egypt.
Ain Shams University, Faculty of Dentistry, Biomaterials Department. Cairo, Egypt.
J Mech Behav Biomed Mater. 2023 Oct;146:106078. doi: 10.1016/j.jmbbm.2023.106078. Epub 2023 Aug 15.
Evaluation of setting time, compressive strength, pH, calcium ion release, and antibacterial activity of mineral trioxide aggregate (MTA) after modification with three different concentrations of nano-graphene oxide (GO) powder compared to unmodified Biodentine as a commercial control.
GO powder, unhydrated and hydrated cements were characterized using Environmental Scanning Electron Microscope (ESEM) with Energy Dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Raman Spectroscopy, and Fourier Transform Infrared spectroscopy (FTIR). GO was also analyzed using Scanning Transmission Electron Microscope (STEM) to determine average lateral dimensions. Specimens were prepared and grouped according to the concentration of GO added to Rootdent MTA (control, 1, 3, and 5 wt%) and the material used (MTA and unmodified Biodentine) into five groups. Setting time was evaluated using Gillmore penetrometer (n = 5). Compressive strength was evaluated using universal testing machine (n = 7). pH and calcium ion release were assessed using pH meter and Induced Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) at 1, 7, 14, and 28 days (n = 7). Antibacterial activity was evaluated against Streptococcus mutans using direct contact test (n = 7). One-way and repeated measures ANOVA followed by Tukey's post hoc test were used for data analysis with significance level set at p ≤ 0.05.
Addition of GO to MTA reduced both initial and final setting time. GO modified MTA groups and unmodified Biodentine showed significantly increased calcium ion release at 14 and 28 days. All cements showed alkaline pH of the storage media at all tested time intervals. 1 wt% GO recorded the highest compressive strength values in MTA modified groups. The increased concentration of GO from 1 to 5 wt% successively increased antibacterial activity of MTA, with Biodentine showing the lowest significant value.
Addition of 1 wt% GO can significantly improve the tested properties of tricalcium silicate-based cements without compromising their compressive strength.
GO is a promising modification for tricalcium silicate cements to improve setting time, compressive strength, and antibacterial activity to provide a variety of materials for different clinical situations. This in turn can reduce the risk of reinfection and allow placement of the final restoration in a single visit.
评价纳米氧化石墨烯（GO）粉末改性矿物三氧化物聚合体（MTA）与未改性 Biodentine 商业对照相比的凝固时间、抗压强度、pH 值、钙离子释放和抗菌活性，GO 粉末、未水化和水化水泥使用环境扫描电子显微镜（ESEM）与能量色散 X 射线光谱（EDX）、X 射线衍射（XRD）、拉曼光谱和傅里叶变换红外光谱（FTIR）进行了表征。还使用扫描透射电子显微镜（STEM）分析了 GO，以确定平均横向尺寸。根据添加到 Rootdent MTA（对照组、1%、3%和 5%wt%）中的 GO 浓度和使用的材料（MTA 和未改性 Biodentine）制备和分组试件，分为五组。凝固时间使用吉尔莫尔渗透计评估（n=5）。抗压强度使用万能试验机评估（n=7）。pH 值和钙离子释放使用 pH 计和电感耦合等离子体-光学发射光谱（ICP-OES）在 1、7、14 和 28 天评估（n=7）。使用直接接触试验评估对变形链球菌的抗菌活性（n=7）。使用单向和重复测量方差分析，然后使用 Tukey 事后检验进行数据分析，显著性水平设置为 p≤0.05。
GO 加入 MTA 可同时降低初始和最终凝固时间。GO 改性 MTA 组和未改性 Biodentine 在 14 和 28 天显示出显著增加的钙离子释放。所有水泥在所有测试时间间隔均显示出存储介质的碱性 pH 值。1%wt%GO 在改性 MTA 组中记录的抗压强度值最高。GO 浓度从 1%增加到 5%wt%，MTA 的抗菌活性依次增加，而 Biodentine 的抗菌活性最低。
添加 1%wt%GO 可以显著改善硅酸三钙基水泥的测试性能，而不会降低其抗压强度。
GO 是硅酸三钙水泥的一种有前途的改性剂，可改善凝固时间、抗压强度和抗菌活性，为不同的临床情况提供多种材料。这反过来又可以降低再感染的风险，并允许在一次就诊中放置最终修复体。
