A 3D-printed tooth a day will keep the doctor away

You've got a dirty mouth. Streptococci, lactobacilli, satphylococci and corynebacteria all find themselves at home in your gob. But fear not, because dental researchers are working on 3D-printed false teeth that can clean things up in there once and for all.

Andreas Herrmann of the University of Groningen and his colleagues have developed an antimicrobial plastic. "The material can kill bacteria on contact, but on the other hand it's not harmful to human cells," Herrmann told New Scientist.

It works by combining antimicrobial ammonium salts with traditional dental resin polymers. The salts are positively charged, and so disrupt the negatively charged bacterial membranes - causing them to burst. Once mixed, it can be put into a 3D printer and used to create replacement teeth, orthodontic braces and more.

More Experiments

In tests, when coated in saliva and streptococcus mutans (a bacteria that causes tooth decay), it killed more than 99% of the bacteria, compared to just 1% in a control sample without the ammonia salts.

However, the tests were only performed over the course of about six days, so more experiments need to be done to ascertain how safe it is over the longer term - especially when used in conjunction with toothpaste.

Herrmann and his team described their invention in an article in Advanced Functional Materials.