Characterization of morphology and composition of inorganic fillers in dental alginates

Abstract

Energy dispersive X-ray spectroscopy microanalysis (EDX), scanning electron microscopy (SEM), and Archimedes' Principle were used to determine the characteristics of inorganic filler particles in five dental alginates, including Cavex ColorChange (C), Hydrogum 5 (H5), Hydrogum (H), Orthoprint (O), and Jeltrate Plus (JP). The different alginate powders (0.5 mg) were fixed on plastic stubs (n = 5) and sputter coated with carbon for EDX analysis, then coated with gold, and observed using SEM. Volume fractions were determined by weighing a sample of each material in water before and after calcining at 450°C for 3 h. The alginate materials were mainly composed of silicon (Si) by weight (C - 81.59%, H - 79.89%, O - 78.87%, H5 - 77.95%, JP - 66.88%, wt). The filler fractions in volume (vt) were as follows: H5 - 84.85%, JP - 74.76%, H - 70.03%, O - 68.31%, and C - 56.10%. The tested materials demonstrated important differences in the inorganic elemental composition, filler fraction, and particle morphology.