Nancy Burton used to be "one of those people who always got sick."

Nancy Burton used to be "one of those people who always got sick."

Since having all her silver amalgam fillings replaced with tooth-colored composite resin, Burton says she's joined the ranks of people who "never get sick."

A licensed acupuncturist, Burton says she became aware of health problems associated with dental work at seminars in Florida, where she studied Chinese medicine.

"I had so many metal fillings," says the 51-year-old Ashland resident. "I just had a whole mouthful.

"Every time you chew on something, you're releasing toxins," says Burton. "Every time you eat something hot, you're releasing more toxins."

During her decade-long practice in Cannon Beach, she became convinced that metal amalgam fillings exacerbated her clients' chronic conditions, such as yeast overgrowth. Last summer, Burton invested about $6,000 in the wholesale removal of her old fillings and their replacement with composite, which she and other holistic health practitioners say is less toxic to the body.

"Heavy metals can affect every aspect of health," says Burton. "I'm still detoxifying from it," she adds, referring to the mercury used in dental amalgam and her efforts to combat the metal's effects with diet, among other holistic methods.

Burton found a sympathetic point of view during a February lecture at Ashland Food Co-op. Certified nutritional therapist Jack Leishman helps clients mitigate mercury off-gassing from their metal fillings by using techniques from ayurvedic medicine and improving their diets.

Leishman's free lecture, titled "Going Mental Over Dental Health?," advocated the Weston A. Price diet, named for a 1930s American dentist who researched the effects of traditional versus industrialized foods on dental health, as well as bacteria in the mouth contributing to poor health in the body's other systems.

Leishman noted that the same year amalgam was first used to fill teeth in Paris — more than 150 years ago — the first case of multiple sclerosis was diagnosed. Later that same year, a rare type of leukemia also was detected in Paris, he says.

"This stuff is carcinogenic," says Leishman.

The dental community, at large, does not agree. With endorsement from the Food and Drug Administration — which upgraded the status of dental amalgam from "low risk" to "moderate risk" last year — the American Dental Association touts the 150-year track record of amalgam, made from 43 to 54 percent mercury and a combination of other metals, such as silver, copper and tin.

Many dentists, however, are eliminating amalgam fillings from their practices. Although well aware of concerns over mercury toxicity, they cite other reasons for using newer technology instead of dentistry's original.

"To me, toxicity is not an issue," says Dr. Greg Miller of Medford's East Main Dental. "The reason we choose (composites) is because they're more compatible with the tooth ... and they look better."

While composite resin — made of acrylic and powdered, glass-like particles — originally was developed for cosmetic applications, the material makes for more than an attractive filling, says Miller. Composite puts less stress on the tooth, reducing the risk of fractures and ultimately dental crowns.

"It expands and contracts at about the same rate as the tooth," says Miller. "To me, they're getting very close to natural tooth structure."

And filling with composite allows dentists to preserve more of the tooth's natural structure, according to the ADA. Whereas dentists drill a sort of dovetail that mechanically holds in amalgam fillings, they drill much less when filling with composite, which bonds to the tooth when hardened.

"Composites, you can make 'em fairly thin and fairly small," says, Miller. "We want to kind of do micro-dentistry."

But Miller, who hasn't used dental amalgam for at least 15 years, is an anomaly among the office's four other partners: Drs. Randy Wooten, Hal Borg, Greg Pearson and Andrew Oas. The dentists fill more and more often with composite, says Pearson, but still give patients a choice of material. Dental amalgam is cheaper and the standard in insurances companies' view.

"I still think they're safe, and the question of toxicity — it just can't be proven," says Pearson. "We've heard it all.

"We have people showing up with MS that are convinced that replacing their silver fillings will reverse the disease process, and that's simply not true."

Dr. James Benson, an Ashland bioesthetic dentist who uses only composite fillings, also dispels the notion that patients will experience improved health after he removes their amalgam fillings. Although plenty of his patients want restoration with composite on the advice of naturopathic physicians, Benson says he encourages patients to put in composite when their amalgam fillings have worn out and need to be replaced anyway. Replacing multiple fillings at once can lead to tooth sensitivity and other complications, he adds.

"It can accentuate a bite disharmony like crazy."

Adhering to the same criteria for replacing fillings as Miller and Pearson, Benson takes a stronger stance on the issue of toxicity.

"I think the ADA is wrong," he says. "Mercury in fish is bad.

"Since there's something that's nontoxic, why should we even fool with that stuff?"

Pearson says there's no way to know whether the safety of composite fillings won't be called into question sometime in the future. And the types that release fluoride — known as ionomer — also could give the alternative medical community reason to denounce them, adds Pearson. Yet more patients, he says, are choosing composites over amalgam, regardless of their practitioners' persuasions.

"We still have a lot of people who want to have one replaced a year."