Objective: This paper reports on the buffering and acid-resistant properties of a modified eggshell–titanium composite against citric acid attack. Materials and Methods: Eggshell–titanium EB-TiO2 was prepared by ball-milling eggshell powder and titanium dioxide. Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Transmission Electron Microscopy (TEM) were used to characterize EB-TiO2. The buffering property against citric acid at pH values of 2, 4, and 5 was measured using a pH meter. Five brands of toothpaste (Colgate, Colgate Sensitive, Aquafresh, Oralwise, and Sensodyne) were used to assess the acid-resistant properties of EB-TiO2. Enamel models were simulated by dissolving each brand of toothpaste with eggshell (control) and EB-TiO2. The samples were exposed to citric acid of pH 2. The average slope (kPa/s) was measured using a pressure sensor. An analysis of variance was used to analyze the kPa/s values (α =.05). Results: The FTIR and XRD analyses suggest the surface modification of EB-TiO2. The TEM image revealed spherical-shaped particles in EB-TiO2. The pH test results showed that the buffering properties of eggshell and EB-TiO2 were comparable. Significant differences were observed in the acid resistance properties of the samples exposed to citric acids (P < .05). The Colgate toothpaste infused with eggshell powder had the highest mean kPa/s values, whereas Sensodyne infused with EB-TiO2 had the lowest kPa/s values. Conclusion: The salient features of this study indicate that modification of eggshell with titanium dioxide does not affect its carbonate buffering properties. Connecting the kPa/s values to acid-resistant properties, EB-TiO2 effectively reduces erosive attacks when added to toothpaste.

中文翻译：

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评估蛋壳-二氧化钛复合材料对腐蚀性酸的缓冲和耐酸性能

目的：本文报告了改性蛋壳钛复合材料抗柠檬酸侵蚀的缓冲和耐酸性能。材料和方法：通过球磨蛋壳粉和二氧化钛制备蛋壳钛 EB-TiO2。傅里叶变换红外光谱 (FTIR)、X 射线衍射 (XRD) 和透射电子显微镜 (TEM) 用于表征 EB-TiO2。使用 pH 计测量 pH 值为 2、4 和 5 时对柠檬酸的缓冲性能。五个品牌的牙膏（Colgate、Colgate Sensitive、Aquafresh、Oralwise 和 Sensodyne）用于评估 EB-TiO2 的耐酸特性。通过用蛋壳（对照）和 EB-TiO2 溶解每种品牌的牙膏来模拟牙釉质模型。将样品暴露于 pH 为 2 的柠檬酸中。使用压力传感器测量平均斜率 (kPa/s)。方差分析用于分析 kPa/s 值 (α =.05)。结果：FTIR 和 XRD 分析表明 EB-TiO2 发生了表面改性。TEM 图像显示 EB-TiO2 中的球形颗粒。pH 测试结果表明，蛋壳和 EB-TiO2 的缓冲性能相当。暴露于柠檬酸的样品的耐酸性特性有显着差异（P < .05）。注入蛋壳粉的高露洁牙膏具有最高的平均 kPa/s 值，而注入 EB-TiO2 的舒适达具有最低的 kPa/s 值。结论：本研究的显着特征表明用二氧化钛改性蛋壳不会影响其碳酸盐缓冲特性。