On Strategy to Inhibit a Biofilm in Provisional Restoration Materials with Silver Nanoparticles

Objectives: The objective of this study was to form a polymeric nanocomposite based on polymethyl-methacrylate and silver nanoparticles to inhibit the formation of a biofilm
Methods: Silver nanoparticles (AgNps) were deposited by in-situ polymerization and spray coating method on the surface of polymethyl-methacrylate (Alike®) with concentrations of 0.01% and 0.03% wt. The AgNps used had an average size of 25 nm. The pure polymer was used as a positive control. The antimicrobial activity was evaluated on a biofilm formed with a dynamic method by the bacterial species Streptoccocus sanguinis and Actimomyces naeslundii, incubated for a period of 7 days in an anaerobic environment. The results were observed in a confocal laser microscope and the biofilm biomass was observed and quantified by the arbitrary fluorescence units
Results: Both experimental groups of the nanocomposite showed an evident difference in the growth of the biofilm with the control group. The nanocomposite formed at 0.03% wt showed a greater inhibitory effect on biofilm formation than the 0.01% wt group, identifying red spots and agglomerates of bacteria, although the statistical difference was not significant using a value of p <.01.
Conclusions: The nanocomposite synthesized based on polymethyl-methacrylate and low concentration of AgNps showed antimicrobial activity on a biofilm formed by A. naeslundii and S. sanguinis