When working in dental laboratories, dust particles are formed, which in most cases have a negative effect on the health of those who are exposed to them. The degree of health risk depends on the composition and concentration of the dust particles and the duration of exposure. Dust consists of solid particles smaller than 1 μm to 100 μm in size that may be present in the air. Exposure to inhaled dust fractions, the smallest particles of which do not stop in the nose or airways but penetrate even the smallest alveoli, can lead to a risk of developing occupational pulmonary diseases. This diploma thesis presents the procedures and materials used by dental technicians, basic characteristics of powders and methods of image analysis, including Feret diameter, circle equivalent diameter, convexity, elongation, circularity and particle shapes. As part of the experimental work, sampling of dust particles was performed between processes of manufacturing various dental replacements with a personal sampler EGO PLUS TT. The first sampling was performed using a ventilation device and the second without the use of a ventilation device. The analysis of the dust particle composition was performed according to ISO 13322-1: 2014 with a field emission gun scanning electron microscope Thermo Fischer Scientific Quattro S. The analysis has shown that the most common dust particles were of alloy origin, most of which oxidized.