Until 2010, Amelia Nuwer, 22, visited the same dentist every year in Biloxi, Miss., her hometown. And every year she came back with a clean bill of dental health: no fillings necessary. Then, as a junior at the University of Alabama, she saw a new dentist who delivered her first negative diagnosis: two cavities. Six months later, the dentist told her she had two more. Earlier this year, he once again had bad news: yet another cavity.
Somehow, in 12 months she had gone from perfect oral health to five fillings. “It felt wrong to me,” she said.
Her hometown dentist was surprised as well. He examined his longtime patient after she graduated. Ms. Nuwer’s so-called cavities, he concluded, had actually been “incipient carious lesions,” a form of early-stage decay that some dentists call “microcavities.”
“He said that he wouldn’t have filled them,” she recalled. “I was so upset and angry.” The five fillings cost her almost $500 out of pocket.
Ms. Nuwer is hardly alone. With increasingly sophisticated detection technology, dentists are finding — and treating — tooth abnormalities that may or may not develop into cavities. While some describe their efforts as a proactive strategy to protect patients from harm, critics say the procedures are unnecessary and painful, and are driving up the costs of care.
“A better approach is watchful waiting,” said Dr. James Bader, a research professor at the University of North Carolina School of Dentistry. “Examine it again in six months.”
Every time a dentist drills into a tooth, he added, “you’re condemning that person to a refilling” years down the road.
An incipient carious lesion is the initial stage of structural damage to the enamel, usually caused by a bacterial infection that produces tooth-dissolving acid.
The lesion doesn’t always lead to a full-blown cavity, which entails decay of the layer right beneath the enamel, called dentin. Mineral-containing saliva can repair these lesions, especially when bolstered with fluoride.
Many experts think it doesn’t make sense to operate in the early stages of decay. “If you don’t have any kind of demonstrable collapse of the enamel wall, then you shouldn’t put in a filling,” Dr. Bader said.
Different dentists hold to different treatment philosophies, and the dental association intentionally offers little guidance. Aside from endorsing the use of fluoride and dental sealants to prevent cavities, the association eschews formal treatment recommendations and “does not have a policy on the treatment of incipient caries,” or decay, according to a representative.
Dr. Douglas Young, a dental diagnostician at the University of the Pacific, thinks that “watchful waiting” doesn’t make sense.
“If you were to go to a physician and he were to diagnose risk factors for heart disease, the physician would take action and treat the early signs of disease and try to prevent future disease,” said Dr. Young, who helped develop a standardized cavity risk assessment adopted by the dental association.
To find incipient caries that can’t be seen with X-rays or the naked eye, dentists like Dr. Young use a variety of new and sophisticated detection methods that include fiber-optic techniques and infrared laser scanning. The Diagnodent is a popular fluorescent light scanner that picks up on abnormalities in tooth density.
Whether to fill based on a Diagnodent reading “depends on the risk,” said Dr. Margherita Fontana, an associate professor at the University of Michigan School of Dentistry. An adult with great dental hygiene is probably at lower risk of seeing a microcavity progress than a teenager who drinks soft drinks all day, she said.
But other experts are critical of the Diagnodent and other early-detection devices because they identify areas on teeth that aren’t actually carious lesions. What’s more, even with a risk assessment, it’s hard to know whether a true lesion will develop into a cavity or not.
“What’s going to happen to it over the next five years is unclear,” Dr. Bader said. “That data isn’t available yet.”