Iron-oxide "nanozymes" could help fight cavities
For people with particularly cavity-prone teeth, daily brushing and flossing aren't always enough. A new treatment could help, as it uses tiny particles known as nanozymes to break down plaque and kill cavity-causing bacteria.
Currently being developed by scientists from the University of Pennsylvania and Indiana University, the experimental technique incorporates two main components: a solution which is applied to the teeth, and a hydrogen peroxide rinse that is subsequently swished in the mouth then spat out.
The solution is called ferumoxytol, and it's already FDA-approved for the treatment of iron-deficiency anemia. It contains iron-oxide nanoparticles that have enzyme-like qualities, and are thus referred to as nanozymes.
Once the ferumoxytol has been applied to the teeth, the nanozymes bind to receptors on the cell membranes of cavity-causing Streptococcus mutans bacteria. When the hydrogen peroxide rinse is subsequently introduced, the iron oxide serves as a catalyst that converts the hydrogen peroxide into oxidants. Those oxidants kill the bacteria by rupturing their membranes, plus they break up the plaque biofilms produced by the bacteria, for easier removal.
The process reportedly doesn't damage the teeth or oral tissues. It also doesn't harm non-target bacteria, due to the fact that the hydrogen peroxide conversion only takes place in highly acidic conditions, such as those that occur when S. mutans bacteria are present and active.
In a test of the treatment, 15 volunteers wore a denture-like appliance that incorporated real tooth enamel, for a 14-day period. Four times each day, they simulated the consumption of sugary foods by applying a sugar-containing solution to the device.
Additionally, twice each day, five of the participants performed the ferumoxytol/hydrogen peroxide therapy, five others performed a variation in which only the inactive (non-nanozyme) ingredients of the ferumoxytol were present, and five others simply rinsed with water. After the two-week period was up, it was found that the tooth-enamel devices worn by the first group contained much less plaque and S. mutans bacteria than those of the other two groups.
A paper on the research, which is being led by the University of Pennsylvania's Prof. Hyun (Michel) Koo, was recently published in the journal Nano Letters.
Source: University of Pennsylvania