A newly-developed dental composite based on nanotechnology kills bacteria and regenerates tooth structure

Maryland dental school professor Huakun (Hockin) Zu, PhD, and a team of researchers at the University of Maryland School of Dentistry are using nanotechnology to create a new dental composite that has the potential to aid dentists in the task of removing more harmful bacteria from a cavity and go one step further – rebuild the tooth.

According to Xu, who also heads up the school's Division of Biomaterials and Tissue Engineering, the new dental filling is comprised of nano-size particles of silver and calcium, along with antibacterial primer and antibacterial adhesive, that treat cavities while also destroying bacteria in the mouth and re-growing tooth structure lost to bacterial decay.

The technology features a primer that is applied to the surface of a drilled tooth, an adhesive to bond the filling to the tooth, and the filling material, which includes a high pH that has been shown to kill bacteria.

When dentists fill a cavity they try to maintain as much tooth structure as possible – which means it can be hard to remove all the bacteria.

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“It’s virtually impossible to get all the bacteria,” Xu said. “Dentists try to preserve as much tooth structure as possible. Bacteria can hide in there and produce acid.” 

When acid invades though cracks or the interface between the filling and tooth structure, the filling fails. Xu said another benefit of the filling he is working on is that he expects it will last much longer than the current standard of about five to 10 years.

Xu said the primer, adhesive and fillings have been tested on the biofilms of volunteers. The next step is to do more testing. Trials both using human teeth and those of lab animals are in the works.

“We will continue to improve and optimize the study,” he said.

The University of Maryland has patents pending on the nanocomposite and the primer and adhesive technologies, and Xu said they are talking with manufacturers about the potential for bringing the product to market.  He said it is too early to say when it may be available.

A multi- and inter-disciplinary approach to the problem of tackling residual bacteria and how to remineralize teeth has led to the potential for what Xu said could be a revolutionary.

Although other labs are working on ways to kill residual bacteria, according to Xu, his team is the  one doing both (killing bacteria and remineralizing the tooth).

He said the technology is working to bring together engineering, biology and dentistry.

“That’s where you can have novel ideas,” he said. “I can look at things from angles that a person in one field would not be able to see.”