Loose an adult tooth, and you’re left with limited options that typically involve titanium implants or plastic dentures. But scientists are working on an alternative: lab-grown human teeth that could one day replace damaged ones. 

Pamela Yelick and Weibo Zhang at Tufts University School of Dental Medicine in Boston have grown a mixture of pig and human tooth cells in pieces of pig teeth to create bioengineered structures that resemble real human teeth.