Local Dentist:

FDA’s Silver Filling Precaution Should Not Concern Most Patients

By John Voket

David Kessler, DDS, of Newtown’s Dental Associates has been practicing for more than 20 years, and he has been advising patients against installing silver or amalgam fillings for at least 15. So he was not too concerned when he learned of a recent FDA ruling that created an official warning about amalgam fillings

According to an Associated Press report issued earlier this week, silver dental fillings contain mercury, and the government for the first time is warning that they may pose a safety concern for pregnant women and young children. The Food and Drug Administration posted the precaution on its website earlier this month, to settle a lawsuit — making the move a victory for antimercury activists.

The warning is not aimed at the general population, only at two groups already urged to limit mercury from another source — seafood — because too much can harm a developing brain. The fillings, formally known as dental amalgams, “contain mercury, which may have neurotoxic effects on the nervous systems of developing children and fetuses,” reads the FDA web posting.

That does not mean it truly harms, and the FDA advises against removing existing fillings.

While Dr Kessler told The Newtown Bee that he agrees with the latter, he has been suspect of the mercury-laced amalgam fillings for some time.

“There has been a question in my mind for a long time about whether or not I want to put mercury in people,” the Dental Associates partner said. “When using amalgam, there are scraps. Now I’m required to store those scraps under oil, pay a hazardous waste disposal company to take them away, I’m supposed to track them to be sure they are disposed of appropriately, and yet the FDA says they are OK for me to put in your body?”

Several other countries limit amalgams, either as a precaution in pregnant women and small children or because of environmental concern. Dental workers make amalgam fillings by mixing liquid mercury with powdered ingredients, requiring special safety steps and filters to limit waste seeping back into the environment.

The federal agency is still studying whether the small amount of mercury vapor released by chewing and brushing is enough to cause neurologic disorders or other problems in youngsters. There have been only a handful of rigorous studies comparing children given either amalgam fillings or tooth-colored resin composite fillings that are mercury-free — and those studies have not detected any brain problems.

Nor has that research settled the long-simmering scientific controversy. Two years ago, the FDA’s own independent scientific advisers said that while amalgam fillings were safe for most people, more research was needed about potential effects on fetuses and children under 6.

Concerns Over

Composite

In regard to that alternative, Dr Kessler recalled that several years ago, there was a bubble of concern over composite or resin fillings as well.

“The fillings contained some material of concern — materials that mimic estrogen in some sealants and composites,” he said. “But we don’t use any at our offices.”

This spring, the FDA put dentists on notice that it is considering additional controls, including whether to require warnings that would advise consumers of the mercury in amalgams before they have a cavity filled, or perhaps even restrict use in small children and certain other patients. It is accepting public comments until July 28.

“It’s an open question what we will do,” FDA Deputy Commissioner Randall Lutter told The Associated Press. But, “what this says is there’s a clear intent on our part on labeling for sensitive subpopulations.”

Expect a final ruling by July 28, 2009, a date set by that legal settlement.

“It’s a watershed moment,” said Michael Bender of the Mercury Policy Project, who with other advocacy groups had sued the FDA in hopes of forcing restrictions on amalgams.

“This court settlement signals the death knell for mercury fillings,” added Charles Brown, an attorney for Consumers for Dental Choice.

Not so fast, say dentists who point to medically crucial reasons to use amalgams — and worry that people who cannot afford more expensive alternatives might avoid dental care.

“We don’t want these choices taken away based on junk science. We don’t want them taken away based on misguided fears,” said Dr Edmond Hewlett, a dental professor at the University of California, Los Angeles, and an American Dental Association adviser.

Amalgam fillings are about 50 percent mercury, joined with silver, copper, and tin. The hardened mixture makes the mercury less absorbable by the body than the kind found in fish, said Dr Hewlett, who chose an amalgam filling for his own 7-year-old son.

Used since the 1800s, amalgams’ popularity already is dropping. They account for about 30 percent of US fillings, still millions of people a year.

They are cheaper than alternatives — roughly $100 for an amalgam filling versus $150 or more for a composite, Hewlett estimates — and they are known as particularly durable. Dr Hewlett said two conditions that demand amalgams: spots on back teeth that dentists cannot keep dry long enough for a composite filling to bond, and in people who forcefully grind their teeth.

Precaution Is Praised

Science operates on “a precautionary principle,” said Dr Karl Kieburtz, a University of Rochester neurologist who co-chaired the 2006 FDA advisory committee and praised the new warning.

“For 99 percent-plus of people, there probably isn’t harm. But if there is a group of people who might be at risk, they should at least have the knowledge that may be so,” he said.

For Dr Kessler and his fellow dentists at Dental Associates, whether it is a new cavity or a concerned patient who comes in with a mouth full of silver, it is more an issue of doing what is best for the existing teeth.

“When time comes to replace, I recommend they don’t use silver. I stopped using amalgam 15 years ago for multiple reasons,” Dr Kessler said. “The most prominent is, in order to use a silver filling, you have to reduce more tooth than an alternative. If you’re going to do a filling, you can use composite, porcelain, and gold. But the latter two require more reduction as well.”

Dr Kessler said his position all along has been, “Anytime you put a drill to a tooth, it’s a bad thing. Our responsibility is to be as conservative as possible.”

He acknowledges, however, that amalgams do break down over time due to heat and cold, and statistically in the past have lasted somewhat longer than composite.

“But that has been more the issue because of dentists who didn’t work with composite very much,” he said. “Today, dentists adept at placing composite as well as amalgam see no difference in the breakdown.”

Ultimately, Dr Kessler said patients who desire the longest lasting fillings probably should consider using porcelain or gold. He said the proof is evident in some of his oldest patients.

“When a 90-year-old patient comes in they might mention they paid $50 for that filling, I know it’s been in there for most of their lives,” he said, adding, “today that gold filling can run more than $1,000.”

Associated Press reporting was also used in this story.