Imagine losing a tooth, going to the dentist's office, and having a gel applied to your gums that would help a new tooth grow in its place. In three weeks, you'd have a brand new tooth. This may not be so far-fetched in 20, or perhaps even 10 years, reports the Academy of General of Dentistry, an organization of general dentists dedicated to continuing education. Researchers recently discovered the gene, called Barx-1, that controls the growth of a tooth.

They used mouse embryos to test the genetic tooth modifications by taking tooth cells that normally create incisors and implanting them with Barx-1. They discovered that new molars grew instead. This knowledge has yet to be tried in the human mouth. Nevertheless, the implication is that Barx-1 may be used with existing tooth cells to grow new teeth for people.

"Although the researchers are at a very early stage in the study, they hope that in 10 or 20 years their work will lead to teeth being grown on demand," says Eric Curtis, DDS, MAGD, spokesperson for the Academy of General Dentistry. "This would cause a major shift in the way dentistry is practiced."

Teeth are one of the few body parts that do not automatically regenerate, explains Dr. Curtis. Unlike skin or bones, for example, damaged teeth do not heal, which is why prevention is so important in dentistry. However, this exciting research may change everything in this field.

"This probably won't happen in my practice lifetime," says Dr. Curtis. "But I can envision a patient coming to a dental office with a lost tooth and having the dentist paint a gel in the space that would stimulate cells to grow new tooth structure. In a matter of weeks, the patient would have a new tooth."

The gel may also stimulate regrowth in existing teeth. For example, a tooth with a cavity would have the gel painted over it, and in a short time, the hole in the tooth would knit back together. This would dramatically reduce the need for a drill in the dental office.

Researchers explained that there are hundreds of genes and message pathways involved in tooth formation, and they have discovered only a few. This is all part of the Human Genome Project, in which researchers are pushing to meet the deadline of sequencing and mapping 100,000 genomes in the human chromosome system by the year 2003. To date, they've mastered 30,000 genomes.

"It sounds like science fiction, but regrowing teeth will probably be in our future," says Dr. Curtis. "We have reason to be cautiously optimistic. It's exciting that researchers have gotten to this stage, but there are still other bugs to work out, like getting a human tooth to grow back in the perfect position in the human mouth."