CATEGORY: DISEASE PREVENTION
A liquid brushed painlessly onto cavities—silver diamine fluoride—halted tooth decay in 50.2% of treated baby teeth after eight months, versus 17.4% of teeth that received a placebo, in a randomized trial of 830 young children published in JAMA Pediatrics.1 That difference of 32.8 percentage points means roughly 33 more cavities stopped for every 100 treated—without a drill, an injection, or an anesthetic anywhere in sight.
A Few Seconds Per Tooth, No Drill Involved
Silver diamine fluoride is a clear liquid that pairs silver, which kills the bacteria driving decay, with fluoride, which helps harden the damaged tooth surface. Applying it takes a tiny sponge-tipped brush and a few seconds per tooth—about the time it takes to paint a fingernail. In this trial, children between the ages of one and six with severe early childhood caries—advanced decay of the baby teeth, averaging about 11 affected teeth per child—were assigned by chance to have either a 38% silver diamine fluoride solution or an identical-looking placebo brushed onto their cavities, once at the start and again six months later. Neither the families nor the dentists scoring the teeth knew who received which. The children were recruited through dental offices, pediatric medical practices, and Head Start preschool programs in Michigan, New York, and Iowa, and examiners rechecked every treated tooth at three, six, and eight months to determine the trial’s main outcome: whether each cavity had stopped progressing.
Half the Cavities Hardened and Stopped
A stopped—or “arrested”—cavity is one whose decayed surface has hardened so the damage is no longer advancing. By three months, 57.5% of cavities treated with silver diamine fluoride had arrested, compared with 18.8% in the placebo group. The gap held through the end of the study: at eight months, 50.2% of treated cavities were arrested versus 17.4% with placebo, a difference of 32.8 percentage points that the study placed between about 22 and 43 points. Side effects were no more common with the real treatment than with the placebo—47.3% of children in the silver diamine fluoride group had some adverse event, nearly all minor, compared with 43.3% in the placebo group—and reports of dental pain did not differ between the two groups.
The Trade-Off Is a Permanent Dark Spot
The treatment’s one conspicuous drawback is cosmetic: silver diamine fluoride permanently stains the decayed portion of the tooth black. The stain marks only the damaged area, not the healthy enamel around it, and because these are baby teeth, the stained tooth is eventually shed on nature’s own schedule. For families, the choice the trial illuminates is between a dark spot on a tooth that was already decayed and the standard alternative for severe early decay—drilling and filling, which in one- to three-year-olds frequently requires treatment under general anesthesia.
An Off-Label Standby Heading Toward Full Approval
Silver diamine fluoride is not new to American dental chairs: it has been cleared since 2014 as a device for treating tooth sensitivity, and dentists have used it off-label against cavities for years. What has been missing is the kind of large, placebo-controlled evidence that supports formal approval as a decay treatment, and this NIH-funded trial was run to supply exactly that—its authors conclude the results support pursuing FDA approval for arresting cavities in young children. The finding also does not stand alone. In a pragmatic school-based trial of nearly 3,000 New York City schoolchildren, a single yearly application of silver diamine fluoride kept pace with the standard combination of dental sealants and fillings at arresting existing decay over two years.2 Together, the two trials cover the ground from toddlers with severe decay to school-age children reached outside a dental office.
Key Takeaways
- In a randomized trial of 830 children under six with severe early childhood decay, silver diamine fluoride halted about half of treated cavities over eight months, versus fewer than one in five with placebo—a 32.8-percentage-point difference.
- Side effects were similar to placebo and dental pain was no different between groups; the one lasting drawback is a permanent black stain on the decayed part of the tooth, which is shed with the baby tooth itself.
- Silver diamine fluoride has been used off-label in the United States since 2014; this trial was designed to support full FDA approval, and a separate school-based trial found it kept pace with sealants and fillings in older children.
References
- Fontana M, Moursi A, Gonzalez-Cabezas C, et al. Efficacy of Silver Diamine Fluoride on Young Children With Severe Early Childhood Caries: A Randomized Clinical Trial. JAMA Pediatrics. Published online July 27, 2026. doi:10.1001/jamapediatrics.2026.2567. link
- Ruff RR, Barry-Godín T, Niederman R. Effect of Silver Diamine Fluoride on Caries Arrest and Prevention: The CariedAway School-Based Randomized Clinical Trial. JAMA Network Open. 2023;6(2):e2255458. link