Effects of a Novel Magnetic Nanomaterial on Oral Biofilms.

Dental caries is one of the most common oral chronic infectious diseases, and novel antibacterial materials must be developed to control plaque and inhibit formation of dental caries. Combining magnetic nanomaterials with antibacterial agents to decrease the formation of bacterial biofilm has been a hot topic in the biomedical field. The present study developed a novel magnetic nanomaterial chemically combined with dimethylaminododecyl methacrylate (DMADDM) and initially investigated its inhibiting effects on biofilms by using traditional caries-related bacteria and saliva flora models. The novel magnetic nanomaterials successfully loaded DMADDM according to thermogravimetric analysis, Fourier transform infrared spectroscopy, x-ray diffraction, vibrating sample magnetometry, scanning electron microscopy, and transmission electron microscopy results. Further, the novel nanoparticle Fe₃O₄@SiO₂@DMADDM with concentration of 8 mg/mL could effectively reduce Streptococcus mutans biofilm and decrease the production of lactic acid. The 16S rDNA sequencing revealed that Fe₃O₄@SiO₂@DMADDM could depress the proportion of caries-related bacteria in saliva-derived biofilm, such as Streptococcus, Veillonella, and Neisseria. Therefore, Fe₃O₄@SiO₂@DMADDM is a novel effective antibacterial magnetic nanomaterial and has clinical potential in plaque control and dental caries prevention.