Although cavities are caused by bacteria, simply killing all of the bacteria in the mouth isn’t a good idea, as some of them aid in digestion or have other beneficial effects. A nanoparticle coating, however, could someday prevent cavities without harming bacteria.
Cavities occur when harmful bacteria such as Streptococcus mutans reproduce to form biofilms (aka plaque) on the teeth – as they do so, they produce acids that dissolve tooth enamel. Previously, scientists have used substances like zinc oxide, copper oxide and silver to eradicate such microbes, but unfortunately those compounds also kill beneficial bacteria.
Instead, a University of Illinois at Chicago team recently focused on stopping the microbes from forming the biofilms, without harming them.
Led by Dr. Russell Pesavento, the researchers studied the effects of nanoparticles made of cerium oxide. While earlier studies suggested that such particles didn’t prevent biofilm formation (and in some cases even promoted it), the U Illinois scientists knew that the qualities of cerium oxide nanoparticles are determined largely by the manner in which they’re made – and their particles were created differently than the others, by dissolving ceric ammonium nitrate or sulfate salts in water.