Old-school technique to treat cavities without fillings gains ground

SPOKESMAN PHOTO: JAKE BARTMAN - Steve Duffin, left, and Mike Shirtcliff, right, are both vocal advocates for the use of silver nitrate and silver diamine fluoride as an effective and inexpensive way to treat cavities.When Wilsonville dentist Steve Duffin began to look for a way to address soaring rates of dental disease at his Keizer clinic 10 years ago, he didn’t expect to find his way into a burgeoning movement in the world of American dentistry.

But when he began to practice a long-forgotten technique for treating cavities without fillings, he discovered what he calls a “miracle” that he believes has the potential to change the lives of the millions around the world who face poor access to dental care.

Duffin became involved with the Oregon Health Plan in 1994, and spent 10 years as the CEO of Capitol Dental Care, which bills itself as “the largest dental contractor with the State of Oregon.”

In 2005, Duffin was lost while driving through Keizer looking for an Oregon Health Plan dentist with whom he’d had a business meeting scheduled. He came across an empty building that looked over Staats Lake and, in a moment of inspiration, decided to open his own clinic there to treat low-income children and their families.

Duffin resigned from his position at Capitol and opened Shoreview Dental later that year, and picked up his drill again.

But there was a problem. Every five years, the State of Oregon documents the state of children’s oral health in its “Smile Survey.” Duffin was troubled by the findings of the 2002 Smile Survey, which found that more than half of the state’s first, second and third graders suffered from untreated dental decay — that is, from cavities.

Worse still was the 2007 Smile Survey, which found that incidents of dental decay had increased by 50 percent from the 2002 survey.

“It was really kind of a frustrating time for me, because I felt like I was in the right place, trying to do the right thing, but we weren’t really making any progress,” Duffin said.

Duffin says that epidemic — which he blames on the rise of high-fructose corn syrup — was so great that he was making weekly trips to the hospital to anesthetize children for treatment. He began to wonder if there was an alternative.

He started at the beginning — the very beginning: he opened a book by G.V. Black, who is considered a progenitor of American dentistry. Duffin had studied Black while a student, but hadn’t heard of a 1908 book called “Pathology of the Hard Tissues of the Teeth” until he heard it mentioned during his inquiry.

Duffin was floored by the sophistication of Black’s work, which correctly identified bacterial infection as the cause of dental decay. Duffin was especially surprised to find that Black — who is known as a father of the modern filling — had also invented a way to treat that bacterial infection with the chemical compound silver nitrate.

Black argued that by applying the substance several times to a cavity, one could kill the bacteria and prevent the cavity from worsening. Duffin found in his research that the technique had, in fact, been widely used in the United States until sometime around the middle of the century, when fillings became the preferred method of treating cavities.SPOKESMAN PHOTO: JAKE BARTMAN - Ashlynn Coster, 7, has silver diamine fluoride applied to several cavities by her mother, Dental Assistant Amber Barnett of Shoreview Dental.

At around the same time as Duffin discovered silver nitrate through Black, he found that dentists overseas were using a chemical called silver diamine fluoride. The substance was essentially silver nitrate mixed with a fluoride, which strengthens tooth enamel.

Duffin met Mike Shirtcliff, the CEO of Advantage Dental, which is an Oregon Health Plan contractor. Shirtcliff had discovered silver diamine fluoride as well, and was working to get the FDA to OK the product. He provided Duffin with a bottle of the substance that was manufactured in Japan.

“I was just blown away with what I saw. There were just amazing results,” Duffin says.

Rather than anesthetizing his patients and performing extensive tooth extractions and fillings, Duffin began to apply the silver diamine fluoride to patients’ teeth. The procedure he developed was to apply the substance three times over the course of approximately as many months, killing the bacteria and protecting the tooth from further decay.

Pending FDA approval, however, Duffin chose to use silver nitrate, since that chemical had already been approved. He would then apply fluoride on top of the treated area, yielding essentially the same effect as could be obtained with the silver diamine fluoride.

Within months, Duffin had stopped taking patients to the hospital entirely, and fillings became a last resort. Better still for patients, the silver nitrate was cheap, costing low-income patients a fraction of what fillings cost.

In the meantime, Duffin and Shirtcliff worked with the FDA to get the silver diamine fluoride approved, which it did in 2014. The FDA also classified the chemical as a fluoride product, meaning that unlike silver nitrate, dental hygienists are permitted to apply it.

Duffin has also increasingly conducted formal research on silver nitrate and silver diamine fluoride. In November 2012, the California Dental Association Journal published as its cover story an article by Duffin called “Back to the Future: The Medical Management of Cavities.”

The article ignited a controversy in the dental community. Some worried that the chemical was unsafe. Advocates argued that it’s no more dangerous than using mercury, phosphoric acid or other chemicals commonly used by dentists. Others criticized the technique for its tendency to turn treated cavities black — a problem Duffin says is negligible in children who will lose their baby teeth soon anyway, or which can be covered with fillings applied without the usual numbing and drilling combination for adults.

“Some of (the controversy) is, I think, influenced by economics,” Duffin said. “Dentists who make their living doing fillings don’t want to be told ‘That doesn’t work; here’s something that does work, and it costs pennies, and the patients really like it.’”

Duffin says that silver nitrate and silver diamine fluoride are nevertheless gaining ground in the dentistry community, and studies are increasingly being conducted by researchers across the country on the substances.

In the meantime, Duffin continues to conduct his own research. And he is working with his son Marcus — a scientist and entrepreneur— to develop a method for doctors, nurses, teachers and community leaders in developing countries to apply silver nitrate and fluoride.

The Duffins have designed a pen-sized tube that allows administration of both silver nitrate and fluoride with ease, and are currently conducting large-scale, year-long pilot programs of the product in Ecuador and Ghana. The goal is to eradicate dental decay where it’s already begun, as in Ecuador, and to prevent it in countries like Ghana where economic development will soon mean more sugar entering the country.

Although he doesn’t want to give out details in advance of an article he’s writing on the studies, Duffin says that the results have been stellar.

“My life is simpler because I’m not doing complex surgical extractions, and root canals and all those things that happen when prevention fails,” Duffin says. “But I’m also happy that something so effective is now growing, and is going potentially to help millions of people.”

Contact Jake Bartman at 503-636-1281 ext. 113 or This email address is being protected from spambots. You need JavaScript enabled to view it..

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