Effect of silver-supported materials on the mechanical and antibacterial properties of reinforced acrylic resin composites

Abstract

The aim of this study was to investigate the effect of silver-supported material (Novaron (N)) in acrylic resin (poly(methyl methacrylate) (PMMA)) composites, which reinforced with zirconium dioxide nanoparticles (nano-ZrO2) and aluminum borate whiskers (ABWs), on the mechanical behavior, antibacterial properties and cytotoxicity. Silanized ABWs (4wt%) and nano-ZrO2 (2wt%) were mixed with PMMA powder to obtain nano-ZrO2–ABW/PMMA matrices. Various amounts of Novaron particles were incorporated into the matrices and the pure PMMA to test the flexural strength. In addition, Streptococcus mutans (S. mutans) and Canidia albicans (C. albicans) biofilms on the specimen surface and in the culture medium were investigated for metabolic activity and colony-forming units (CFUs). Extracts taken in the cell culture medium of the specimens were used to evaluate cell viability. Results showed that the silanized nano-ZrO2 and ABWs could improve the flexural strength of composites compared with the pure PMMA. Novaron itself had no mechanical function for composites while it had synergistic effect when it mixed with silanized nano-ZrO2 and ABWs. And when 4wt% (N-4) Novaron mixed in nano-ZrO2–ABW/PMMA composites, flexural strength achieved an increase of 44%, getting the maximum value. For the antibacterial properties, the values of MTT and CFUs of S. mutans and C. albicans biofilms on the composites surface were greatly reduced (p<0.05) with the higher proportion of Novaron, and no significant difference was found in the culture medium. The composites did not have an adverse affect on fibroblast growth in this study (p>0.05).