By Maura Lerner
June 4, 2004
Star Tribune
Four years ago, worrying about dental fillings was just a preoccupation for Leo Cashman. Now it's a full-time job. Cashman, 59, has turned his south Minneapolis apartment into the headquarters of a grass-roots movement to rid the world of mercury fillings and other perceived health dangers.
As executive director of DAMS (Dental Amalgam Mercury Syndrome) International, Cashman will share the spotlight this morning at a special public meeting of the Minnesota Board of Dentistry in St. Paul. The board has agreed to revisit a perennial hot-button issue that has hounded dentistry for more than a century: How safe are those silver-color fillings, called dental amalgams, in millions of mouths? Cashman and his allies blame the mercury in the fillings for a long list of ailments, from depression to infertility, cancer and multiple sclerosis. "It links to all the leading causes of death in this country, every one of them," Cashman said. "We don't claim that dental mercury is the be all and the end all," he added, but that it's a factor, like smoking. "When you have amalgams, your fillings are smoking mercury."
The dental profession in large part dismisses the critics as misguided fanatics, and says that they're scaring consumers into wasting money to remove fillings for no good reason. "If we thought that the removal of amalgams would cure any of those diseases or conditions, we'd be the first ones to say 'get them all out,' " said Dr. Frederick Eichmiller, director of the American Dental Association's research center in Gaithersburg, Md. "Every time that it's been studied there is no evidence [of harm]. It's been reviewed many, many times. We probably don't have a material that's been more thoroughly studied than amalgams."
But the anti-mercury movement has been gaining steam lately, thanks in part to groups like DAMS. "A lot of people find us on the Internet," said Cashman, an accountant-turned-activist who took over as executive director in 2000 (the Web site is www.amalgam.org). "We probably need to be a thousand times bigger than we are." Cashman spreads the word on what he calls the "dark side of dentistry.' " "We think people are better served by dentists who avoid putting poison in your mouth," said Cashman, whose group has an estimated 1,500 members.
Operating out of a home-office stuffed to overflowing with books and files, he fields calls and e-mails from worried consumers around the world. He publishes a newsletter called "Dental Truth," which recently featured a cover story on Lisa Marie Presley's "dental mercury crisis." He ships information packets, which he assembles in his kitchen, to anyone who asks, and he will refer callers to mercury-free dentists anywhere in the country. In addition, he sells dozens of books and videotapes, including "Root Canal Coverup,"Let the Tooth Be Known," and the latest hot seller, "The Fluoride Deception" ("It reads like a thriller novel," Cashman said). Like many converts to the cause, Cashman said he had his own run-in with mercury. At age 40, he had his first dental filling and quickly fell into a downward spiral -- he was exhausted, he said, and had difficulty concentrating. Reading up on holistic medicine, he became convinced that the mercury filling was to blame, and had it removed. "The light went on," he said. "It all fit perfectly for me." It took two years to recover, he said. He joined the board of DAMS as a volunteer in 1997, and he became its one and only employee in 2000.
"Leo Cashman has done incredible stuff to build this movement," said Charlie Brown, a lawyer with the Coalition for Mercury-Free Dentistry in Washington, D.C., which has asked Minnesota and other states to publicize the dangers of dental fillings. Cashman said he gets a lot of help from volunteers. "They passionately want to put out the alert on the health effects of mercury," he said. "I don't have to go out and recruit people. They just bend my ear."
Roots of debate
The debate is almost as old as mercury fillings themselves. In the early 1800s, dentists started mixing mercury with other metals -- tin, silver, copper -- to make fillings that could survive in the turbulent, moist environment of the mouth. The amalgams were reliable, relatively easy and cheap to use. Some dentists refused to go along, arguing it was dangerous, which split the profession into two factions. Eventually, the majority embraced amalgams, and criticism faded. But the debate has flared up periodically ever since.
Today, both sides insist that science is on their side. The critics, like Cashman, start with the premise that mercury is a poison, and that any exposure is dangerous. They point to studies that have found that the fillings leak mercury vapor, and that people with more amalgam fillings have higher concentrations of mercury in their organs. Animal studies appear to confirm those findings. "It is the same mercury that the Food and Drug Administration is warning about in fish," said Freya Koss, an activist with the anti-mercury coalition. "But it's OK to put in your body?" But the dental profession points to studies that have tried, and failed, to find any increase in health problems among people with fillings. "The vast majority of studies that are out there ... have shown no evidence for harm," said Prof. Joel Rudney of the University of Minnesota School of Dentistry. More studies are underway. Supporters concede that the fillings release a mercury vapor, but say the exposure is minuscule. "What science and experience tells us is that amalgam, like all other dental filling materials currently in use, is safe and effective," said the American Dental Association (ADA) position paper. Cashman calls it a coverup -- "one of the most serious and dangerous coverups of all time." And he's looking forward to today's hearing. "It's an opportunity to get our issues out there," he said. "Every little bit helps."
Maura Lerner is at mlerner@startribune.com.