Chew on this: We'll soon be able to grow replacement teeth

WASHINGTON — As long as there are hockey players, there will be niche markets for false teeth. But the real news about the future of dentures is that there isn't much of one.

Toothlessness has declined 60 percent in the United States since 1960. Baby boomers will be the first generation in human history typically to go to their graves with most of their teeth.

And now comes tooth regeneration: growing teeth in adults, on demand, to replace missing ones. Soon.

It turns out wisdom teeth are prolific sources of adult stem cells needed to grow new teeth for you. From scratch. In your adult life, as you need them. In the near future. According to the National Institutes of Health.

For thousands of years, losing teeth has been a routine part of aging. That's over.

"We're there, right now," said Pamela Robey, chief of the Craniofacial and Skeletal Diseases Branch at the National Institute of Dental and Craniofacial Research, part of the National Institutes of Health. "A lot of people will go and never lose a tooth. With good health care and proper habits, there's no reason to lose a tooth."

The introduction of fluoride into drinking water and toothpaste is viewed as one of the 10 greatest public-health accomplishments of the 20th century, according to the Centers for Disease Control and Prevention (CDC).

It did not occur without controversy. In the renowned 1964 black comedy "Dr. Strangelove," Brig. Gen. Jack D. Ripper (Sterling Hayden) attacks the Soviet Union with nuclear-armed B-52s, hoping to thwart a communist conspiracy to "sap and impurify" the American people with fluoridated water.

Leslie Seldin has some perspective on this. He graduated from dental school in 1966 and was the editor of "The Future of Dentistry," a report published in 2001 by the American Dental Association.

"When I was growing up" — in the '50s — "reaching the teen years you'd develop enormous amounts of decay," he said. It wasn't until the '60s, when most baby boomers were growing up, that fluoridation really started having a major impact.

By the '90s, "if new patients came in that were young people, under 30, you really were surprised if you saw significant" cavities, Seldin said.

Fundamentally intact teeth, plus the increased attention to gum disease that can loosen them, have brought about a transformation.

"When I started out in dentistry, in my practice it wasn't uncommon for people losing their teeth — you took out all their teeth and made a denture. You were working on a denture at all times," Seldin said.

"Now, five new dentures a year, that's a lot. We go out of our way to avoid them."

So what's the future of dentures?

"Hopefully, they will become a relic," said Mary MacDougall, director of the Institute of Oral Health Research at the University of Alabama. "Like Washington's false teeth."

Regenerating a whole tooth is no less complicated than rebuilding a whole heart, said Songtao Shi, of the University of Southern California, who heads a team working on creating such a tooth.

Not only do you have to create smart tissue (nerves), strong tissue (ligaments) and soft tissue (pulp), you've got to build enamel — by far the hardest structural element in the body.

And you have to have openings for blood vessels and nerves. And you have to make the whole thing stick together. And you have to anchor it in bone. And then you have to make the entire arrangement last a lifetime in the juicy stew of bacteria that is your mouth.

It's a nuisance, but researchers are closing in on it. They think the tooth probably will be the first complex organ to be completely regenerated from stem cells. In part, this is because teeth are easily accessible.

So are adult stem cells, abundant in both wisdom and baby teeth, and your immune system won't reject your cells.

Nobody is predicting when the first whole tooth will be grown in a human, although five to 10 years is a common guess.

"The whole tooth — we've got a long way to go," Shi said.