Researchers at the University of Birmingham have shown how the development of coated silica nanoparticles could be used in restorative treatment of sensitive teeth and preventing the onset of tooth decay. The study, published in the Journal of Dentistry, shows how sub-micron silica particles can be prepared to deliver important compounds into damaged teeth through tubules in the dentine.

The tiny particles can be bound to compounds ranging from calcium tooth-building materials to antimicrobials that prevent infection.

“The dentine of our teeth has numerous microscopic holes, which are the entrances to tubules that run through to the nerve,” said Professor Damien Walmsley. “When your outer enamel is breached, the exposure of these tubules is really noticeable. If you drink something cold, you can feel the sensitivity in your teeth because these tubules run directly through to the nerve and the soft tissue of the tooth. Our plan was to target those same tubules with a multifunctional agent that can help repair and restore the tooth, while protecting it against further infection that could penetrate the pulp and cause irreversible damage.”

The aim of restorative agents is to increase the mineral content of both the enamel and dentine, with the particles acting like seeds for further growth that would close the tubules. Previous attempts have used compounds of calcium fluoride, combinations of carbonate-hydroxypatite nano-crystals and bioactive glass, but all have seen limited success as they are liable to aggregate on delivery to the tubules. This prevents them from being able to enter the opening, which is only 1-4 microns in width. However, the Birmingham team turned to sub-micron silica particles that had been prepared with a surface coating to reduce the chance of aggregation. When observed using high-definition scanning electron microsopy (SEM), the researchers saw promising signs that suggested that the aggregation obstacle had been overcome.

 For more information, visit www.birmingham.ac.uk.