Evaluation of the morphology of fillers of modern dental nanocomposite materials

In the course of the research work, the morphological characteristics of the inorganic filler of five commercial and one experimental dental restorative composite materials containing nanosized particles were assessed using a Tescan Vega 3 LMH scanning electron microscope (Tescan, Brno, Czech Republic). Scanning electron microscopy revealed that the studied samples of imported paste-like composite materials contained fillers similar in shape and size: prepolarized conglomerates of irregular shapes ranging from 3 to 40 µm, consisting of nanoscale spheres less than 200 nm in size, and individual spherical particles up to 200 nm in size. The prepolarized filler in the low-modulus (flowable) imported composite had a smaller diameter of 3 to 30 µm and a more regular spherical shape. The fillers in the Russian-produced composite materials had fragmented particles, with some of the filler consisting of micron-sized clusters ranging from 5 to 30 µm, formed by nanoscale spherical particles less than 100 nm in size. The experimental composite material contained microspheres ranging in size from 5 to 20 µm, consisting of nanoscale spherical particles up to 450 nm in size. In terms of morphological structure, the experimental composite is comparable to fillers of modern imported commercial dental composite materials.