dental filling of the future

The new filling contains calcium phosphate nanoparticles that rebuild tooth minerals.

Thanks to a new dental breakthrough, the dreaded trip to the dentist to replace a worn-out filling could soon be a thing of the past.  Scientists have used nanotechnology to create the first cavity-filling composite that kills harmful bacteria and regenerates tooth structure lost to decay.

Rather than just limiting decay with conventional fillings, the new material controls harmful bacteria, which co-exist in the natural colony of microorganisms in the mouth.

It also works to remineralize the tooth, said study leader Professor Huakun Xu from Maryland University School of Dentistry.

He said: ‘Tooth decay means that the mineral content in the tooth has been dissolved by the organic acids secreted by bacteria residing in biofilms or plaques on the tooth surface.

‘These organisms convert carbohydrates to acids that decrease the minerals in the tooth structure.’

After a dentist drills out a decayed tooth, the cavity still contains residual bacteria, which it’s not possible for a dentist to remove.

The researchers added antibacterial agents containing silver nanoparticles into primer used to prepare a drilled-out cavity and into adhesives that dentists spread into the cavity to make a filling stick tight to the tissue of the tooth.

Prof Xu said: ‘The reason we want to get the antibacterial agents also into primers and adhesives is that these are the first things that cover the internal surfaces of the tooth cavity and flow into tiny dental tubules inside the tooth.’

The main reason for failures in tooth restorations, says Xu, is secondary caries or decay at the restoration margins. Applying the new primer and adhesive will kill the residual bacteria. The antibacterial agent also has a high pH to limit acid production.

The prepared tooth would be filled with a nanocomposite containing calcium phosphate nanoparticles that regenerate tooth minerals.

Fillings made from the School of Dentistry’s new nanocomposite, with antibacterial primer and antibacterial adhesive, should last far longer than the typical five to 10 years, though the scientists have not thoroughly tested longevity.

The new products have been laboratory tested using biofilms from saliva of volunteers.

Prof Xu’s team is planning to next test its products in animal teeth and in human volunteers in collaboration with the Federal University of Ceara in Brazil.

Via Daily Mail