Introduction: Due to teeth loss, a large proportion of the elderly rely on full or partial dentures for aesthetics, speaking, and eating. A variety of polymers are used for the production of removable prostheses, including poly(methyl) methacrylate. Poly(methyl) methacrylate is a widely used material for making denture bases. However, it is not an ideal material due to its harmful effects on soft tissues, porosity, and surface roughness that allow the accumulation of microbes, especially Candida albicans, on the denture base, which is the main cause of underdenture stomatitis. Purpose: The purpose of the bachelor’s thesis is to determine how the physical properties of the differently treated PMMA surface affect the adhesion of C. albicans. We will also try to find out how the polyelectrolyte multilayer coating of PAA and PAH affects the adhesion of C. albicans. Methods: We prepared samples from cold polymerizing acrylate. All samples were first sandblasted with 50 µm Al2O3. A quarter of the samples were sandblasted, a quarter was polished with pumice stone and polishing paste, and a polyelectrolyte multilayer of polyacrylic acid and polyallylamine hydrochloride was applied to half of the samples. Half of these samples were finished with a PAA layer and half with a PAH layer. This was followed by the measurement of the physical properties of the surfaces. We measured roughness, zeta potential, and hydrophobicity. A pure culture of C. albicans was prepared in the microbiology laboratory. We looked at the adhesion of yeast to differently treated surfaces. In the dental laboratory, we made upper and lower total dentures, the base of which was made of PMMA. Results: The highest roughness was measured for the sandblasted surface (98,8 nm ± 46,6 nm), followed by the surfaces with a polyelectrolyte multilayer, and the least rough was the polished surface (11.1 nm ± 1.3 nm). The surface with PAA had the highest zeta potential (1.53 mV ± 2.09 mV). The sandblasted and polished surface, however, had a negative zeta potential, the latter having the lowest zeta potential (-40.84 mV ± 2.48 mV). The contact angle was greater than 90° for all surfaces, which means that all surfaces were hydrophobic. The sandblasted surface had the largest contact angle (124.74° ± 4.62°), followed by the surface with a polyelectrolyte multilayer, and the smallest contact angle was measured on the polished surface (94.98° ± 7.36°). The greatest yeast adhesion was detected on the polished surface (503 yeasts), followed by a polyelectrolyte multilayer, which ended with a PAA layer (278 yeasts) and sandblasted surface (51 yeasts) while the least amount of C. albicans adhered to the surface with the polyelectrolyte multilayer, which ended with a PAH layer (31 yeasts). Discussion and conclusion: The results of this study show that more yeast adheres to polished surfaces than to sandblasted surfaces. If we compare surfaces with a polyelectrolyte multilayer, however, we can see how more C. albicans adhere to the negatively charged surface (PAA) than to the repulsively charged surface (PAH). The contact angle was similarly large for all surfaces, so it is difficult to determine the influence on the adhesion of C. albicans.
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