Effect of Superparamagnetic Iron Oxide Nanoparticles on Dental BiofilmFormed on Polymethyl Methacrylate Surface

Background and Objective: Considering the direct relationship between dental plaques and primarytooth decay, gum infections (such as gingivitis and periodontitis), and chronic cardiovascular diseases,different strategies have been presented to deal with biofilms in the oral cavity. Among these strategies,metal nanoparticles, especially superparamagnetic iron oxide nanoparticles, are very important due totheir anti-biofilm properties and ability to respond to an external magnetic field. Superparamagnetic ironoxide nanoparticles have different antibacterial mechanisms to remove dental plaques, including physicaldamage and increasing the permeability of the bacterial membrane, morphological change, intracellularaccumulation, disruption of protein synthesis, and ultimately bacterial death. . Therefore, the aim of thisresearch is to investigate the anti-biofilm effect of superparamagnetic iron oxide nanoparticles on thedental biofilm formed on the surface of polymethyl methacrylate.Methods: In this study, Streptococcus mutans bacteria, which is the main cause of primary tooth decay,was used to form biofilm on the surface of polymethyl methacrylate which was treated with plasma andcovered with protein. Therefore three modes, including, integration of biofilm with nanoparticles with amechanical stirrer, integration of biofilm with nanoparticles with the application of a magnetic field, andintegration of biofilm with superparamagnetic iron oxide nanoparticles without using a magnetic field ormechanical stirrer, were compared. Then, they were examined by calorimetric method with crystal violetat the wavelength of ۵۷۰ nm and MTT test in terms of viability (۱% concentration of nanoparticles wasused during the test).Findings: The obtained results showed that the use of a ۱% suspension of superparamagnetic iron oxidenanoparticles in the presence of a mechanical stirrer or in the presence of an external magnetic field couldsignificantly (P-value ≤ ۰.۰۵) reduce the mass of Streptococcus mutans biofilm. The application ofmagnetic nanoparticles without any magnetic field or mechanical stirrer had no significant effect onbiofilm reduction.Conclusion: Superparamagnetic iron oxide nanoparticles alone had no effect on bacterial viability, but inthe presence of a mechanical stirrer or an external magnetic field, the biofilm mass was reduced.

کلیدواژه ها:

Dental biofilm ، Polymethyl methacrylate surface ، Streptococcus mutans ، Superparamagneticiron oxide nanoparticles