Silver Diamine Fluoride Stops Cavities Without Drilling, Large Trial Finds

A dentist holds a tiny sponge-tipped applicator, dips it in a clear liquid, and paints it onto a decayed baby tooth. It takes seconds. There is no drill, no needle, no sedation. According to a large clinical trial led by the University of Michigan, that simple gesture can halt a cavity in more than half of the teeth treated.

The liquid is silver diamine fluoride, or SDF. The trial, a Phase III study published in JAMA Pediatrics, enrolled 830 children younger than 6. They were recruited through dental clinics, pediatric medical practices, and Head Start and Early Head Start programs in Michigan, New York, and Iowa. Head Start and Early Head Start are federally supported programs that provide early childhood education and related services to eligible families. The researchers tested a 38% SDF solution applied at six-month intervals, and it stopped decay in more than half of the affected baby teeth.

Dentists call this arresting decay: the damaged area stops getting worse. It is not a repair. Unlike a filling, SDF does not replace lost tooth structure. Silver acts against the bacteria associated with decay, while fluoride strengthens the tooth's mineral structure and helps it resist further damage. Margherita Fontana, a professor at the University of Michigan School of Dentistry and the study's lead investigator, called it a very effective and safe treatment, even in children as young as 1.

The stakes are practical. Tooth decay is the most common chronic disease among American children, affecting more than 40% of them. Cavities may cause few symptoms at first, but untreated decay can lead to severe toothaches, infections, trouble eating and sleeping, missed school, and repeated medical visits. Each year, thousands of young children in the U.S. land in emergency departments because of it. Emergency physicians generally cannot provide the dental care that would fix the underlying problem, so some children go home still in pain or with infection. Others eventually need dental surgery under general anesthesia. Conventional treatment is also hard on the very young, some of whom cannot stay still through a procedure or are frightened by it.

There is a real tradeoff. SDF permanently turns the treated, decayed part of a tooth dark, which is most noticeable on front teeth. The discoloration is mainly cosmetic, but it may shape whether families choose the treatment. Nor is SDF right for every cavity, and stopping decay does not necessarily end the need for future dental work. For some children, repeat applications every few months might hold a cavity in check until the baby tooth falls out naturally. Fontana said adults could benefit too, as could older people, people with developmental or physical disabilities, those with severe dental anxiety, and patients who struggle to get conventional care. For adults, SDF might manage decay long term or serve as a bridge until a filling becomes affordable or practical.

SDF itself is not new. Dentists in many countries have used it for decades. In the United States, the FDA approved it in 2014 as a medical device for tooth sensitivity, and dentists have since used it off-label to stop cavities. What has been missing is large-scale evidence from U.S. populations on its safety and effectiveness for decay. The trial began in 2018 and continued through the disruptions of the COVID-19 pandemic. Fontana said that for broader adoption, including in medical settings, carefully collected U.S. data was needed, and now exists. She noted that young children often see pediatricians years before any dentist, so wider acceptance could let more cavities be treated, while a referral to a dental home is arranged, before they become painful, infected, or surgical. A dental home means an ongoing relationship with a provider for prevention, treatment, and follow-up.

The work involved researchers from the University of Michigan, New York University, the University of Iowa, and Indiana University, with more than $12 million from the National Institute of Dental and Craniofacial Research, part of the National Institutes of Health. The product tested was Advantage Arrest 38% SDF, supplied by Elevate Oral Care. The manufacturer can now use the results in an application to the FDA to approve SDF as a drug for arresting dental caries.

Amr Moursi, a professor of pediatric dentistry at NYU College of Dentistry and a co-principal investigator, said the results support such approval. He argued that ending off-label status could mean more use by providers, better insurer payments, and more consistent product quality. Whether the FDA acts on an application is the next thing to watch.