Councilwoman Blondell Reynolds Brown, who championed a cause that she initially knew nothing about, yesterday said she recently had written her dentist with instructions to put no more dental amalgam in her 12-year-old daughter's teeth.
To her surprise, he responded that he had stopped using it three years ago.
The information sheet, which contains no dire warnings or even recommendations, was researched and written by physicians and scientists on the city Board of Health.
"It is about disclosure and consumers' right to know," Brown said.
The sheet mainly describes types of fillings (primarily silver-gray colored dental amalgam vs. white tooth-colored resin composite) and boils complicated scientific questions down to understandable bits.
A bullet point noting that "high levels of mercury can cause toxic effects on the brain, nervous system, and kidneys" is followed by another that says, "The mercury levels in people with amalgam fillings are not high enough to be considered toxic."
But the city's move generated intense disagreement from outside groups, starting with the title on top: Information Sheet - Amalgam dental fillings containing mercury.
The Philadelphia County Dental Society, which would have preferred nothing at all, argued for removing the word mercury. The group says that the form in the filling is perfectly safe and that simply naming the metal could scare away people who need dental care and are already afraid of the drill.
Consumers for Dental Choice, which believes dental amalgam should be banned, wanted to add the word toxic to the headline. The group believes that mercury in fillings may cause several major disorders, including multiple sclerosis and Alzheimer's disease.
Mainstream scientific consensus, backed by voluminous research, is that the substance in dental amalgam - elemental mercury, as opposed to the organic mercury that is responsible for warnings about consumption of fish - is harmless as a mixture encapsulated inside the tooth. Mercury is about 50 percent of the mix, which also includes silver, tin, copper and zinc.
But mercury vapor does escape into the mouth, and elemental mercury under certain conditions could convert into an organic form. Some studies have raised concerns.
And the U.S. Food and Drug Administration, which for years had stated that the fillings are safe, abruptly changed course last June, cautioning about possible neurotoxic effects "on the nervous systems of developing children and fetuses." It also reopened a long-delayed re-evaluation process and is sifting through more than 1,400 comments with a final ruling on safety and guidance due by by July 28.
That change in position carried weight with the Philadelphia Board of Health.
"As a physician, just beginning to read the literature, I began this track thinking there was no conclusive proof of a danger," said Marla J. Gold, a board member who also is dean of the Drexel University School of Public Health. The FDA update "raises an eyebrow," she said.
For Gold, the next question in how to approach the contentious issue from a broad public health perspective - what people need to know in order to make informed decisions while not scaring them with competing claims - was: "Is there an alternative? And yes, there is."
In fact, resin composite fillings have been improving and gaining in popularity. An estimated 50 percent or more fillings in this country are now made of resin. That is partly because of the controversy but mostly, according to the American Dental Association and its local affiliates, because they look better, undistinguishable from teeth. Resin composites have down sides - they typically wear out sooner and are not ideal in some situations.
They also cost more - $156, say, for a simple, one-surface composite filling vs. $116 for an amalgam. - because materials are more expensive and they take longer to place. Most dental insurance policies will cover either procedure but the reimbursement is based on the cheaper amalgam.
Many dentists say their biggest concern about anti-mercury campaigns is that between higher costs and unwarranted fears, some segments of the population will not get the care they need.
"Children from low socioeconomic groups who have barriers to access to dental care" could be put "more at risk," said Ann Slaughter, a member of the city's Board of Health and an assistant professor at the University of Pennsylvania School of Dental Medicine.
Freya Koss, an anti-mercury campaigner, has a very different view.
Seven days after getting a dental amalgam removed and replaced by a New York dentist in 1998, she walked out of a concert at the Annenberg Center with doublevision. She was initially diagnosed with multiple sclerosis or lupus; an Internet search led her to suspect mercury.
Koss, who lives in Wynnewood, had all of her fillings removed - something that neither she nor others recommend as a routine because of added risks of mercury exposure - and began various special treatments that she says gradually lessened a series of neurological symptoms.
"I knew I was mercury poisoned," said Koss, 67, who founded the Pennsylvania Coalition for Mercury-Free Dentistry and brought the issue to City Council.
A more nuanced view comes from Herbert L. Needleman, a professor of psychiatry and pediatrics at the University of Pittsburgh School of Medicine.
Needleman is not a mercury expert. He is one of the leading authorities on lead, and he played a key role in raising the alarm about lead paint, an unknown threat that turned out to be one of the biggest health scourges of the last century.
There are similarities in "the trajectory of discovery of the toxic effects" of lead and mercury, he cautions. "The court is still out on it."
At the dental office in Society Hill on Tuesday, Kareem Johnson said that regardless of any brochure, he felt confident that his 10th amalgam would not put him at risk.
"I've had mercury fillings since I was 8," said Johnson, a psychologist at Temple University.
Text of the new information sheet:
Contact staff writer Don Sapatkin at 215-854-2617 or firstname.lastname@example.org.