Nanoparticles may help prevent tooth decay

                Scientists have found a way to use nano-particles to effectively break down plaque and wipe out more than 99.9% of cavity-causing bacteria within minutes, an advance that may help better prevent tooth decay. The bacteria that live in dental plaque and contribute to tooth decay often resist traditional antimicrobial treatment, as they can “hide” within a sticky bio-film matrix, a glue-like polymer scaffold.

                Researchers at University of Pennsylvania took a more sophisticated approach. Instead of applying an antimicrobial to the teeth, they took advantage of the pH-sensitive and enzyme-like properties of iron-containing nano-particles to catalyse the activity of hydrogen peroxide, a commonly used natural antiseptic.

                The activity hydrogen peroxide produced free radicals that were able to degrade the bio-film matrix and kill the bacteria within, significantly reducing plaque and preventing the tooth decay, or cavities, in an animal model. “Even using a very low concentration of hydrogen peroxide, the process was incredibly effective at disrupting the bio-film,” said Hyun Koo, from the University of Pennsylvania. “Adding nano-particles increased the efficiency of bacterial killing more than 5,000 fold,” said Koo.

                Previous research showed that iron oxide nano-particles behave similarly to a peroxidase, an enzyme found naturally that catalyses oxidative reactions, often using hydrogen peroxide.