Sugar-loving bacteria cause cavities, but killing all bacteria in the mouth isn’t healthy because some of them have beneficial effects, including aiding digestion. A University of Illinois at Chicago (UIC) team has discovered that a nanoparticle coating could prevent cavities without harming good bacteria.
When harmful bacteria such as Streptococcus mutans feast on sugars, they reproduce to form biofilms, commonly known as plaque, on the teeth. This is how cavities form. As the plaque builds up, they produce acids that dissolve tooth enamel. Scientists have previously used silver, copper oxide, and zinc oxide to remove such microbes, which worked, but unfortunately, those compounds also eradicated beneficial bacteria.
Instead, the UIC team led by Dr. Russell Pesavento focused on stopping the microbes from forming the biofilms, without harming them.
The researchers investigated the effects of nanoparticles made from cerium oxide. Earlier studies promoted such particles, while others suggested that it didn’t prevent the formation of biofilm at all. However, the UIC scientists knew that the qualities of cerium oxide nanoparticles are determined primarily by how they’re developed. Therefore, their particles were made differently than the others, by dissolving sulfate salts or ceric ammonium nitrate in water.
In the laboratory, the team seeded polystyrene plates with a growth medium consisting of S. mutans bacteria, which were fed the sugars that they use to build plaque. When the new cerium oxide nanoparticles solution was added to those plates, the plaque reduced by 40% and was shown to be less toxic to human oral cells overall.
Dr. Pesavento plans to combine the nanoparticles with enamel-strengthening fluoride, in a coating paste that dentists could paint onto patients’ teeth. However, much work needs to be completed before it can be distributed to dentists around the world.
On Aug 18, a virtual meeting on this topic was presented online at the American Chemical Society.
