Background:
Reconstruction of damaged or missing tooth parts primarily involves the use of prosthetic restorations. Various polymers are used in dental prosthetics, most frequently acrylate materials such as polymethyl methacrylate (PMMA). This material is characterized by exceptionally low water absorption and high mechanical strength. The disadvantage of this material is its susceptibility to microbial colonization, which can provoke local and systemic infections. In laboratory conditions, nanoparticles are increasingly being used to improve the mechanical properties of acrylate materials, which typically exhibit more favourable physical, chemical and biological properties.

Aim of the study:
To evaluate the effect of nanosilver addition on the mechanical properties of acrylate material.

Material and methods:
The study was conducted using Vertex Trayplast, a self-curing acrylate material. Five study groups were prepared for each test: a control group and four study groups modified with Sigma-Aldrich silver nanoparticles at concentrations of 0.05%, 0.5%, 1.5%, and 2.5% by weight. Hardness, impact strength, three-point bending strength and wettability angle were measured, and surface free energy was determined. The Fisher test for a normal distribution was used for statistical analysis, with a Tukey post-hoc test. When normality was not assumed, the Kruskal-Wallis test was used.

Results:
The studies have shown that the addition of silver nanoparticles to PMMA acrylic material has no effect on its mechanical properties. Vickers hardness varied slightly depending on the nanoAg concentration. Impact strength in most cases did not differ significantly from the control group, and bending strength showed only minor changes, at the same time, statistical analysis did not show any statistically significant differences. The addition of nanoAg did, however, affect surface properties: an increase in wetting angles and a decrease in surface free energy were observed, indicating increased hydrophobicity of the material.

Conclusions:
Within the tested concentration range, nanosilver does not adversely affect the mechanical properties of the self-cured acrylate material. Adding nanosilver at higher concentrations results in mechanical properties closer to those of the unmodified acrylate material. Nanosilver can be used in the production of customized trays due to its antibacterial and antifungal properties.