Phase III Trial Finds Painted-On Liquid Stops Cavities in Young Children Without Drilling

Every year, untreated tooth decay pushes thousands of young U.S. children into emergency departments and, eventually, operating rooms. Many end up under general anesthesia so dentists can fix cavities they couldn't treat any other way. A new Phase III trial suggests there's a cheaper, faster, needle-free option that works.

The study, led by researchers at the University of Michigan School of Dentistry and published this week in JAMA Pediatrics, tested a liquid called silver diamine fluoride, or SDF, in 830 children under age six. Researchers recruited those kids through dental offices, pediatric medical practices, and Head Start and Early Head Start programs across Michigan, New York, and Iowa, according to a University of Michigan news release reviewed for this story.

The application itself takes seconds. A clinician touches a small sponge-tipped applicator to the cavity. No drilling, no injection, no sedation chair. According to findings reported in JAMA Pediatrics, 38% SDF applied every six months arrested decay in 54% of treated lesions at the six-month mark, compared with 22.5% in the placebo group. At eight months, arrest rates were 50.2% for SDF versus 17.4% for placebo.

The study enrolled children with severe early childhood caries, the subset of kids whose decay is extensive enough that conventional care often means a trip to a surgical suite. That matters for interpreting the numbers: this wasn't a mild-cavity population. These were kids pediatric dentists describe as the hardest to treat in a chair.

Professor Margherita Fontana, a professor of dentistry at the University of Michigan and the trial's lead investigator, told the University of Michigan news office that the treatment was effective and safe, including in children as young as one.

There's a real tradeoff to flag. SDF permanently darkens the decayed areas it arrests. The treated spot turns black. For baby teeth that will eventually fall out, many families may find that acceptable. Whether they do is a conversation between clinician, parent, and in some cases a three-year-old who has opinions about their smile.

The equity angle is hard to ignore here. The trial specifically recruited through Head Start programs, which serve low-income families. Severe early childhood caries hits harder in communities with less access to regular dental care. General anesthesia for dental work carries real risk in very young children, and the literature on dental surgery under general anesthesia notes that the condition disproportionately affects lower-income and minoritized communities. A liquid that costs a fraction of an OR visit and can be applied in a pediatrician's office or a community clinic is a different kind of tool.

SDF isn't new to dentistry. The FDA granted it breakthrough therapy designation in 2017, and dentists in many countries have used it off-label for years. What the U.S. has lacked until now is Phase III efficacy and safety data sufficient to support an FDA application for its use specifically as a cavity treatment in children. The trial's authors said the findings provide that evidence, according to reporting by Dentistry.co.uk on the published results.

The study doesn't answer every question. Longer-term follow-up data on what happens to those teeth after the arrest period would add to the picture. And regulatory review, if a sponsor moves forward with an FDA application, takes time.

But for the pediatric dentist trying to figure out what to do with a two-year-old who won't open her mouth and has six cavities, and for the parent who can't afford to miss work for a surgical center appointment, this trial moves SDF from "interesting off-label option" to "evidence-backed intervention." That's a different conversation to have at a well-child visit.

Sources cited:
- JAMA Pediatrics (via University of Michigan News) (https://news.umich.edu/drill-free-cavity-care-one-minute-one-tiny-brush-one-pivotal-trial/)
- Dentistry.co.uk (https://dentistry.co.uk/2026/07/30/silver-diamine-fluoride-childhood-decay-trial/)
- Technology Networks (https://www.technologynetworks.com/drug-discovery/news/non-invasive-pain-free-treatment-stops-tooth-decay-in-children-415063)
- MedicalXpress (https://medicalxpress.com/news/2026-07-silver-diamine-fluoride-treatment-halt.html)