Gingivitis Prevention: Integration of Iron (II, III) Oxide Nanoparticles into Commercial Mouthwash

Gingivitis Prevention: Integration of Iron (II, III) Oxide Nanoparticles into Commercial Mouthwash

J. Nguyen, M. Osinski

University of New Mexico, Albuquerque, New Mexico 87120

2010 Data from the Center for Disease Control and Prevention estimated that 64.7 million of American adults are victims of periodontitis, a dangerous and irreversible periodontal disease. The early form of periodontitis is gingivitis, a reversible, yet widespread disease that is commonly overlooked. Therefore, experimentation is taking place to incorporate nanoparticles into dental care. Metal oxide nanoparticles have outstanding antimicrobial abilities, but may cause cytotoxicity within the human body. The high number of periodontitis patients and the biomedical limitations of nanoparticles have led to the need for non-toxic antimicrobial substances that are safe to be used in dental care products. A solution to this need may be found in the incorporation of iron (II, III) oxide nanoparticle in commercial mouthwash.

Iron (II, III) oxide (Fe₃O­₄) nanoparticles are of great interest due to their size and their effectiveness towards eliminating bacterial biofilm. Using iron acetylacetonate (Fe(acac)₃) as our precursor, the Fe(acac)₃ was dissolved in triethylene glycol (TREG), which does not stimulate the immune system and made the nanoparticles water-soluble. After the nanoparticle synthesis, the behavior of these particle was then analyzed in water and Listerine Coolmint mouthwash.

The results showed that the nanoparticle synthesis was very efficient as it produced a 93% yield. Three characterization methods using dynamic light scattering, zeta potential, and transmission electron microscopy (TEM) were utilized. The analysis from the characterization methods confirmed that the average radius of one nanoparticle spanned approximately 5 nm, which is small enough to penetrate bacterial biofilm, and that all the particles displayed uniform size and shape distribution. The nanoparticles also displayed high colloidal stability in water. The same colloidal stability is predicted to be present within the nanoparticles dispersed in Listerine Coolmint mouthwash.

Further progress in our methods will require us to receive approval from the Institutional Review Board to obtain gingival swabs from gingivitis patients. The mixed culture bacteria from these swabs will further be propagated using agar on disks of hydroxyapatite (a prominent mineral found in human teeth). A series of matrix studies will be conducted with two control groups and an experimental group. All groups will be subject to the same environment on an orbital shaker in an incubator at human body temperature. The first control group will contain gingival bacteria subject to no treatment, the second control group will involve exposing gingival bacteria to plain Listerine Coolmint mouthwash, and the experimental group will include various concentrations of nanoparticles in mouthwash applied to gingival bacteria. Each group will be examined after increments of 10, 30, and 60 seconds. The viability of the gingival biofilm will be examined using the LIVE/DEAD BacLight Bacterial Viability Kit and cell culture size counting.

The characterization data from the Fe₃O­₄ nanoparticles suggest that the nanoparticles may be highly effective as a biomedically innocuous antimicrobial that, when combined with Listerine Coolmint Mouthwash, can increase the potency of the mouthwash. This creates a promising dental care treatment that can be easily incorporated into routine dental hygiene practices to effectively prevent the onset of gingivitis and periodontitis.