Annotation. The aim of the study was to investigate and compare the primary and residual adhesion of microorganisms to the surface of dental prostheses made of Russian palladium-based alloys “Palladent” and “Palladent-UNI”. Samples of ceramic-coated and uncoated alloys were used. As a result of the study, the data were obtained that the ceramic-coated “Palladent-UNI” alloy samples showed a better statistically reliable result than the “Palladent” alloy samples. It was found that the zone of alloys and ceramic coating connection creates additional conditions for microorganisms fixation and increases the level of adhesion of some strains by 1.25—1.5 times. The obtained results showed low indices of primary adhesion of aggressive microbiota to the studied alloys. © 2025 Elsevier B.V., All rights reserved.