A new strategy conceived by University of Pennsylvania researchers took a more sophisticated approach. Instead of simply applying an antibiotic to the teeth, they took advantage of the pH-sensitive and enzyme-like properties of nanoparticles to catalyse the activity of hydrogen peroxide. The activated hydrogen peroxide produced free radicals that were able to degrade the biofilm matrix and kill the bacteria within, significantly reducing plaque and preventing tooth decay.
“Even using a very low concentration of hydrogen peroxide, the process was incredibly effective at disrupting the biofilm,” said Hyun (Michel) Koo, a professor in the Pennsylvania School of Dental Medicine and senior author of the study: “Adding nanoparticles increased the efficiency of bacterial killing more than 5,000-fold”.
The researchers confirmed that the nanoparticles adhered to the biofilm, were retained even after treatment stopped and could effectively catalyse hydrogen peroxide.
They showed that the nanoparticles’ reaction with a 1% or less hydrogen peroxide solution was remarkably effective at killing bacteria, wiping out more than 99.9% of the it in the biofilm within five minutes, an efficacy more than 5,000 times greater than using hydrogen peroxide alone. Even more promising, they demonstrated that the treatment regimen, involving a 30-second topical treatment of the nanoparticles followed by a 30-second treatment with hydrogen peroxide, could break down the biofilm matrix components, essentially removing it.