3D printed teeth and braces that kill bacteria developed

Researchers have developed 3D printed teeth and orthodontic braces that can kill bacteria, without causing any harm to human cells.
Andreas Herrmann of the University of Groningen in the Netherlands and his colleagues have developed an antimicrobial plastic, which allowed them to 3D print teeth that also kill bacteria.
The team embedded antimicrobial quaternary ammonium salts inside existing dental resin polymers. The salts are positively charged and so disrupt the negatively charged bacterial membranes, causing them to burst and die, 'New Scientist' reported.
"The material can kill bacteria on contact, but on the other hand it's not harmful to human cells," said Hermann.

Researchers then put this mix in a 3D printer, hardened it with ultraviolet light and printed out a range of dental objects such as replacement teeth and orthodontic braces.
They coated samples of the material in mix of saliva and Streptococcus mutans, the bacterium that causes tooth decay. They found the material killed over 99 per cent of the bacteria, compared to less than 1 per cent for a control sample without the added salts.
Further tests will have to be done before the material could be available to patients, as the team only left the samples in the saliva and bacteria mix for six days.

Researchers also have to confirm if the plastic is strong enough to use as a tooth.