Antimicrobial false teeth made with 3D printing

New Scientist : False teeth traditionally require making molds, which is an uncomfortable process for patients, and the false teeth are themselves still at risk to plaque and bacteria. Now Andreas Herrmann of the University of Groningen in the Netherlands and his colleagues have used 3D printing to create false teeth from an antimicrobial plastic. Starting with a digital scan of a tooth that didn’t require making a mold in a patient’s mouth, they embedded quaternary ammonium salts into existing dental resin polymers. The salts are positively charged ions, which disrupt negatively charged bacterial cell membranes so that they rupture and die. Tests showed that the material killed more than 99% of the bacteria in a saliva sample. The researchers intend to test the teeth for an extended period in the lab; they also plan to study how the altered polymers maintain their strength and how they react with toothpastes. But they expect that 3D printed teeth could be adopted by dentists relatively quickly.