They are hailed as medicine’s greatest hope for the future.
Stem cells, in particular embryonic stem cells, because of their unique ability to grow into specific types of tissue, may eventually be used to treat some of the most devastating diseases, including Alzheimer’s disease and diabetes, as well as spinal cord injuries.
La Jolla’s Burnham Institute, the Salk Institute, the Scripps Research Institute, and UC San Diego are all hoping to make significant contributions.
Meanwhile, a team of scientists at the National Institutes of Health also hope to turn stem cells into therapies , but mainly to re-create smiles.
Pamela Gehron Robey, a bone cell biologist and chief of the craniofacial and skeletal disease branch of the National Institute of Dental and Craniofacial Research in Washington, D.C., found that stem cells derived from noncontroversial sources of baby teeth, wisdom teeth and the jawbone hold promise to save injured teeth or to replace them completely and to treat patients with periodontal, or gum diseases.
“We are about five to 10 years away from re-creating a tooth (as a possible substitute for the current use of dental implants),” Gehron Robey said.
Gehron Robey said her team, led by Song Tao Shi, who devised a technique to isolate the stem cells and apply them to dental tissue, looks at one approach to regrow teeth. Scientists elsewhere experiment with other approaches to do the same.
In simplified terms, scientists would put stem cells in a crown mold, loop it with blood vessels and then let a tooth form, she said.
The work, however, is still in its infancy.
“We have proof of principle that you can put the cells in the crown mold and create a structure that is shaped like a tooth,” she said.
This was done in mice. It will take at least five more years before researchers will be able to try to do the same in people, she said.
Susan Lovelace, the executive director of the San Diego County Dental Society, said scientists have been working for more than a decade on trying to grow real teeth. They’ve had little success, she said.
“There are a number of hurdles,” Lovelace said. “Even if you re-create the tooth, you still have to figure out how to implant it so it takes root and grows into the bone and becomes an integral and functioning part of the dentition.”
“The challenge is to grow it,” Gehron Robey said. Dentists have been able to regrow teeth, but only with patients’ own lost and found teeth, and only if they were treated right away.
A Better Option
Lovelace agreed with Gehron Robey that the current use of dental implants to replace missing or lost teeth isn’t optimal.
Besides aesthetics issues, dental replacement surgery doesn’t work in all patients, and even if successful, the screw that holds the fake tooth in place sometimes loosens, causing the implant to fall out, Gehron Robey said.
According to the American Dental Association, patients must be in good health, have healthy gums and adequate bone to support the implant before they can even be considered for the procedure.
Lovelace said there’s no doubt that implanting naturally grown teeth, if successfully done, would appeal to patients.
“A patient with a natural tooth will feel better and look better , you don’t see the screw part when a person smiles, but they know it’s there,” Lovelace said.
Cost, however, likely will be an issue.
“Every time you have a new technology, you need to recoup research and development costs,” Lovelace said.
Gehron Robey, however, says the cost to implant a natural tooth would be comparable to dental implants, which can run between $10,000 and $15,000 per surgery.
According to a 2002 survey done by the ADA, people lose fewer teeth as they age, but more Americans choose dental implants as a replacement option than they did in the past.
Responses from 3,000 dentists revealed that surgically placed dental implants rose 49 percent in a four-year period to 56.2 implants placed yearly by dentists in 1999 vs. an average of 37.7 in 1995.
Gehron Robey said some companies, whose names she didn’t want to disclose, have expressed interest in her work. For now, her focus is on “cutting-edge science,” she said.
Scientists in San Diego’s biotech hub on the Torrey Pines Mesa are waiting for Proposition 71 grant proposals to start to do their part of cutting-edge science.
In November, four research institutions on the Mesa , the Burnham Institute, Salk Institute, Scripps Research Institute and UCSD , formed a consortium to work on joint projects and apply for grants from the California Institute of Regenerative Medicine, the $3 billion taxpayer-funded initiative approved as Proposition 71.
The process, however, is complicated by legal challenges and ethical concerns over using cells derived from human embryos.