Colonization of silicone-based soft lining materials by pathogenic yeast-type fungi is a common problem associated with the use of dentures. In this study, silver sodium hydrogen zirconium phosphate (SSHZP) was introduced into polydimethylsiloxane-based material as an antimicrobial filler at concentrations of 0.25, 0.5, 1, 2, 4, 6, 8, 10, 12, and 14% (w/w). The in vitro antimicrobial efficacy was investigated. Candida albicans was used as a characteristic representative of pathogenic oral microflora. Staphylococcus aureus and Escherichia coli were used as the typical Gram-positive and Gram-negative bacterial strains, respectively. The effect of filler addition on the Shore A hardness, tensile strength, tensile bond strength, sorption, and solubility was investigated. An increase in the filler concentration resulted in an increase in hardness, sorption, and solubility, and for the highest concentration, a decrease in bond strength. The favorable combination of antimicrobial efficacy with other properties was achieved at filler concentrations ranging from 2% to 10%. These composites exhibited mechanical properties similar to the material without the antimicrobial filler and enhanced in vitro antimicrobial efficiency.

The silicone based room temperature vulcanized (RTV) polymers are commonly used materials for medicine, especially for dentures and maxillofacial prostheses. Unfortunately, the colonization of those materials by pathogenic microorganisms is wellknown problem related with their applications. The aim of presented study was to examine antibacterial properties of RTV silicone for dentistry modified with silver nanoparticles. Design/methodology/approach: The silver nanoparticles were introduced into twocomponent system silicone based materials. The presence of silver nanoparticles was investigated with scanning electron microscope (SEM). The antibacterial activity against Streptococcus mutans was determined. The result were statistically analysed with a Statistica 12.5 software and non-parametric Kruskal-Wallis test (α = 0.05). Findings: The silver nanoparticles introduction into RTV-silicone allowed to enhance the antimicrobial resistance against standard strain of Streptococcus mutans. Research limitations/implications: In this research only Streptococcus mutans

Purpose: Silicone materials crosslinked during the hydrosilylation reaction are common in dental prosthetics and dentistry. These materials are characterized by a relatively very good properties. However, one of the fundamental problems associated with the use of such polymers is a low resistance to microbial colonization. Numerus fillers with antimicrobial potential have been used experimentally for a decade. Anyway point of concern in this type of work is the use of commercially available materials as the matrix. However, the composition of the matrix for this materials is not clearly known. Therefore, the aim of this study was to obtain a two-component silicone material, crosslinking at room temperature, with properties corresponding to the needs of dental prosthetics, in particular as denture soft linings. Such material would be a starting point to obtain more sophisticated compositions, however, of known composition in full. Design/methodology/approach: As the matrix the mixtures of polymers were prepared. As the "catalyst" component a vinyl polydimethylsiloxane with platinum catalyst in xylene was prepared. As the "base" component a mixture of vinyl polydimethylsiloxane with methylhydrosiloxane -dimethylsiloxane copolymer was made. One of the two fillers differing in the functionalizing was added into prepared substrates (10 or 15% by weight) and ultrasonically homogenized. The Shore A hardness, tensile strength, bond strength to denture base material, water sorption and solubility were investigated. Measurements were made after different aging periods in distilled water at 37±1°C. Findings: The study showed an increase in mechanical properties with increasing concentrations of fillers. The type of filler significantly affects the test results. Increasing the aging time effects on increasing the hardness of materials. Water absorption and solubility were within the desired range. Research limitations/implications: Research limitations/implicationsThe results of the presented research may be generally dependent on technology of fillers introduction into polymers matrix. 23READING DIRECT: www.archivesmse.org Practical implications:The results show promising properties of the tested materials. It can be used as starting material for further studies on soft or super soft denture lining and other materials characterized by similar requirements. Originality/value: The method of receiving silicone -based composites with properties required for the selected prosthetic materials, especially denture soft linings was presented. Their properties were similar to commercially available products.

The paper analyses the influence of chemical composition of silicone-based composites on their properties in the aspect of using them as long-term soft denture lining materials. Different concentrations of filler and methylhydrosiloxane-dimethylsiloxane copolymer were used. The filler was introduced into the composite with mechanical mixing combined with ultrasonic homogenization. Scanning electron microscopy was used to investigate the quality of filler dispersion. Shore A hardness, tensile strength, sorption, solubility and tensile bond strength to poly(methyl methacrylate) were measured. Tests show satisfactory results for some experimental composites, which met all the requirements for such materials.