Evaluating the buffering and acid-resistant properties of eggshell–titanium dioxide composite against erosive acids

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-TiO ₂ 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-TiO ₂ . 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-TiO ₂ . Enamel models were simulated by dissolving each brand of toothpaste with eggshell (control) and EB-TiO ₂ . 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-TiO ₂ . The TEM image revealed spherical-shaped particles in EB-TiO ₂ . The pH test results showed that the buffering properties of eggshell and EB-TiO ₂ 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-TiO ₂ 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-TiO ₂ effectively reduces erosive attacks when added to toothpaste.