Being told that your three-year-old needs several fillings under general anesthesia is one of the more frightening conversations in pediatric medicine. It is also expensive, often requires a hospital or surgical center, and carries the anxieties that come with sedating a small child.
A large new trial gives parents in that position something concrete to raise. Published in JAMA Pediatrics, the phase 3 study found that a liquid painted onto a cavity in a few seconds, with no drilling, no injection, and no sedation, arrested decay in more than half of affected baby teeth when applied every six months.
The liquid is silver diamine fluoride, or SDF. It is not new, it is not a cure, and it comes with a trade-off parents need to understand before agreeing to it. What is new is that there is now large-scale US trial evidence behind it.
What the Trial Found
The trial enrolled 830 children under age 6 with severe early childhood caries, recruited through dental offices, pediatric medical practices, and Head Start and Early Head Start programs across Michigan, New York, and Iowa. Participants were randomly assigned to 38% SDF or placebo.
Researchers found that SDF arrested decay in more than half of affected baby teeth when applied at six-month intervals. Margherita Fontana, professor of dentistry at the University of Michigan School of Dentistry and the study's lead investigator, described it as a very effective and safe treatment, even in children as young as 1.
The counterpart to that number deserves equal billing. If more than half of treated teeth had decay arrested, a substantial share did not, and those teeth still needed something else. The study began in 2018 and was funded by more than $12 million from the National Institute of Dental and Craniofacial Research. The product used, Advantage Arrest 38% SDF, was provided by the manufacturer Elevate Oral Care.
Tooth decay is the most common chronic disease of childhood, affecting more than 40 percent of US children. Left untreated, it causes pain, infection, difficulty eating and sleeping, and missed school.
Where SDF Fits, and Where It Does Not
SDF stops decay from progressing by killing bacteria and hardening softened tooth structure. That is a different job from what a filling does.
A filling removes decayed tissue and restores the shape and function of the tooth. SDF does neither. It arrests the process, leaving the cavity in place. For a baby tooth that will fall out on its own in a few years, arresting decay until then is often all that is required. For a tooth with a large structural defect, or one that already has an abscess or infection that needs drainage, SDF is not the answer.
It also is not permanent on its own. Reapplication every six months, and in some protocols more often, is part of how it works.
Fontana noted that SDF may be especially valuable for very young children, older adults, people with developmental or physical disabilities, patients with severe dental anxiety, and others who cannot easily tolerate or access conventional treatment. That list describes exactly the populations for whom conventional dentistry most often escalates to sedation.
One point of confusion is worth clearing up, because fluoride has been in the news. The FDA's recent action on ingestible fluoride products concerns swallowed drops and tablets given to young children. SDF is applied topically to a tooth surface in a tiny quantity. They are different products used in different ways, and the FDA action does not apply to SDF.
The Trade-Off Parents Actually Have to Weigh
SDF's main drawback is cosmetic, and it is not subtle. The silver permanently darkens the decayed portion of the tooth, turning it black.
That staining is confined to the decayed area, not the whole tooth, and it does not come off. On a back molar it is largely invisible. On a front tooth it is not, and parents of a preschooler who is about to start school photos should be told plainly what the tooth will look like before consenting.
Set against that is what the alternative involves. General anesthesia for dental restoration in a young child means a procedure with anesthesia risk, fasting beforehand, a recovery period, and costs that frequently reach thousands of dollars. Access is its own barrier, with waits at hospital-based pediatric dental programs often running months while decay continues progressing.
For many families, a black spot on a baby tooth that will be replaced anyway is an easy trade. For others it is not. It is a legitimate parental judgment rather than a clinical error either way, and a dentist who dismisses the cosmetic concern is not giving good counsel.
What to Ask a Pediatric Dentist
The useful questions are specific. Ask whether every tooth needs restoration or whether some could be arrested with SDF while others are restored, since these are not mutually exclusive and a mixed approach is common. Ask which teeth are involved, how visible they are, and whether any tooth has an infection that SDF cannot address.
Ask what the timeline is if SDF is used and it does not fully arrest a lesion, and what the reapplication schedule would be. Ask whether the practice applies SDF at all, because not every general dentist does.
On cost, ask whether SDF is covered by your plan or Medicaid in your state, and what the out-of-pocket difference is between SDF and treatment under anesthesia. Coverage varies considerably and is one reason the researchers are pursuing formal approval.
Signs that a child needs prompt dental attention regardless of which route is chosen include facial swelling, fever with mouth pain, refusal to eat, a tooth that has turned dark, or pain that wakes the child at night. Facial swelling with fever is an urgent problem, not a scheduling one.
What Happens Next on Approval and Coverage
SDF has been used by dentists in many countries for decades and in the United States off-label since 2014, when it was cleared as a medical device for tooth sensitivity rather than approved as a drug for cavities. This trial was designed to produce the evidence a manufacturer needs to submit a dental caries drug application to the FDA.
Amr Moursi, professor of pediatric dentistry at New York University College of Dentistry and a co-principal investigator, said that removing SDF from off-label status would be an important innovation that could lead to greater use, better insurance payment, and more consistent product quality. That is an investigator making a case for the product he studied, which is reasonable but is an argument rather than a finding.
The confirmed development is that a phase 3 trial in 830 US children found 38% SDF arrested decay in more than half of treated baby teeth. The families most affected are those facing dental treatment under general anesthesia for a preschooler. The most reasonable step is to ask a pediatric dentist whether SDF is appropriate for some or all of the affected teeth. The central uncertainty is whether the FDA approves it and whether insurers follow.
Frequently Asked Questions
What is silver diamine fluoride? A liquid painted onto a cavity that stops decay from progressing by killing bacteria and hardening softened tooth structure. It requires no drilling, injection, or sedation.
What did the trial find? In 830 children under 6 with severe early childhood caries, 38% of SDF arrested decay in more than half of affected baby teeth when applied every six months.
Does it replace fillings? No. It arrests decay but does not remove decayed tissue or restore the tooth's shape. It cannot treat an existing abscess or infection.
What is the downside? The silver permanently turns the decayed portion of the tooth black. The staining is confined to the decayed area and does not come off.
Is it FDA approved for cavities? Not yet. It was cleared in 2014 as a device for tooth sensitivity and has been used off-label for cavities since. This trial was designed to support a future drug application.
Is this related to the FDA warnings about fluoride? No. Those concern ingestible fluoride drops and tablets that children swallow. SDF is applied topically to a tooth surface.
When should I seek urgent dental care? Facial swelling, fever with mouth pain, refusal to eat, or pain that wakes a child at night warrant prompt attention. Facial swelling with fever is urgent.
