Physicochemical characterization of a dental eggshell powder abrasive material

Background: This study aimed to determine the physicochemical characteristics of an eggshell-based dental abrasive material. Methods: The eggshell powder abrasive material (EPAM) was synthesized by ball milling eggshell powder and surfactants. Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM) and a laser diffraction particle size analyzer (PSA) were used to characterize EPAM. In addition, the abrasive characteristics of EPAM were evaluated by comparison using poly(methyl methacrylate) (PMMA) resins. Surface roughness (R-a) was measured using a profilometer. Results: The FTIR spectroscopy and XRD analysis confirmed that the carbonate product was primarily calcite (97.3%) with traces of graphite 2H (1.3%) and thenardite (1.4%). The TEM imagery revealed irregular particles in EPAM. The PSA analysis of the particle size distribution showed EPAM to be a superfine powder (0.3 mu m to 50 nm). In addition, the 50-nm EPAM (R-a = 0.04 mu m) measured the lowest R-a value when compared with pumice (R-a = 0.08 mu m). Conclusions: The salient features of this study indicate that EPAM can naturally replace calcite, which is generally mined and used as a dental abrasive material. In addition, and regarding the abrasive characteristics of EPAM in reducing the surface roughness of PMMA resin specimens, this study conclusively showed that EPAM effectively reduces the surface roughness below the threshold limit value of 0.2 mu m. Potentially, EPAM could reduce waste disposal problems while enabling an economic benefit from using eggshell waste material.