Evaluation of Antibacterial Effect of Silver and Copper Oxide Nanoparticles in Denture Base Material Against Streptococcus mutans and Escherichia coli

Abstract

Objective: Heat cure acrylic is the most common used material for fabrication of dental prosthesis. This in vitro study was undertaken to discover the effect of nanoparticles on antibacterial properties of the dental base.
 Methods: Nanosized Silver and Copper oxide were impregnated at 1%, 3% and 5% by weight to the monomer of methyl methacrylate with the aid of probe sonicator before mixing it with acrylic powder. Seventy samples were prepared to determine the effect of the nanoparticles on Streptococcus mutans and Escherichia coli. 
 Results: The results for Streptococcus mutans revealed a statistically significant difference (p<0.05) for both nanoparticles at the three concentrations except for 1% silver. The most influential concentration on the tested material was 3% copper oxide which caused a 49% decline. Regarding Escherichia coli, only 3% and 5% of silver showed a statistically significant difference.
 Conclusions: Within the limitations of this in vitro study, it can be concluded that the addition of Silver nanoparticles into heat-cure acrylic was more effective against Streptococcus mutans than Escherichia coli. Regarding Copper oxide nanoparticles, it caused a drastic reduction in Streptococcus mutans activity but with no significant effect on Escherichia coli for all of its concentrations. Since denture stomatitis is caused by both bacterial species, Silver nanoparticles might be considered as a suitable additive for reducing denture induced infections.