Some animals continually lose and replace their teeth. Kim Loos Dr. Kimberly A. Loos practices general dentistry in San Jose, California. She is also a clinical instructor at University of Pacific School of Dentistry and an editor for Dentistry On-Line. During our lifetime, it may be possible to replace a decayed or knocked out tooth with a new regrown tooth.
Humans normally produce only two sets of teeth.
When Barx-1 is inhibited, incisors grow. Scientists were able to uninhibit Barx-1, which caused mouse cells to produce molars instead of incisors. After about three days, the altered cells were implanted near the kidney of an adult mouse. The blood around the kidney nourished the manipulated cells. Three weeks later, a tooth had grown near the mouse's kidney.