A liquid that stops cavities in young children, no drill needed

The full story behind my Short: In a phase III trial of 830 young children (JAMA Pediatrics, 2026), silver diamine fluoride stopped 54% of treated cavities at 6 months vs 22.5% with placebo. It leaves a permanent black stain.

The short version

Silver diamine fluoride (SDF) is a liquid that a dentist brushes onto tooth decay with a small sponge-tipped applicator. It takes seconds per tooth and needs no drill, needle or sedation. A large University of Michigan–led trial has now tested it properly in young children with severe tooth decay [1][2].

830children aged 12–71 months with severe early childhood caries
54.0% vs 22.5%cavities arrested at 6 months: SDF vs placebo (one application)
50.2% vs 17.4%arrested at 8 months, after a second application at 6 months
No differencein pain; adverse events similar (47.3% vs 43.3%)

What they found

The phase III, multisite, randomised, blinded, placebo-controlled trial enrolled 830 children aged 12 to 71 months with severe early childhood caries in Michigan, New York and Iowa. Children received 38% SDF or a placebo at the start and again at 6 months [1].

The share of treated cavities that had stopped progressing (arrested) was 57.5%, 54.0% and 50.2% at 3, 6 and 8 months with SDF, compared with 18.8%, 22.5% and 17.4% with placebo [1]. Pain did not differ between the groups, and adverse events were similar (47.3% vs 43.3%; treatment-related 22.9% vs 22.2%) [1].

The study was funded by the National Institute of Dental and Craniofacial Research (more than $12 million) [2][3].

Limits and caveats

  • Black stain. SDF permanently stains the decayed part of the tooth dark/black [2][3].
  • Not every cavity. About half of treated cavities were arrested at 8 months, so it didn't work on all of them [1].
  • Drop-outs. 584 of 830 children (70%) completed the study; the COVID-19 pandemic contributed to losses [1].
  • US regulation. SDF was cleared by the FDA in 2014 as a device for tooth sensitivity; using it for cavities is off-label. The researchers say the results support FDA approval for treating decay [2].

Watch the Short

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AI voice note: the narration in this Short is my own voice, cloned with AI.

Why it matters

Tooth decay affects more than 40% of children in the US [2], and treating it in very young children often means drilling, needles or sedation. A quick, painless liquid could help many children get treatment sooner, though the stain and the need for follow-up care are real trade-offs. Ask your dentist whether it's suitable for your child.

Full narration (transcript)

A liquid that stops cavities. No drill, no needles. It's called silver diamine fluoride. A dentist dabs it onto the decay in seconds. Now a phase three trial, led by the University of Michigan and published in JAMA Pediatrics, has tested it in 830 young children with severe tooth decay. They got either the liquid or a placebo. Six months after one coat, 54 percent of treated cavities had stopped progressing, versus 22.5 percent with the placebo. After a second coat, at eight months, it was 50 percent versus 17 percent. Pain and side effects were similar in both groups. The catch: it permanently stains the decayed spot black, and it stopped about half of the cavities, not all of them. Also, about 3 in 10 children didn't complete the study. In the US, using it on cavities is still off-label. The team says these results support full FDA approval. Follow the link to the main website for much deeper information.

Sources

  1. [1] Fontana M et al. (2026). Silver diamine fluoride for arresting caries in young children: a randomized clinical trial. JAMA Pediatrics 180(9):942. doi:10.1001/jamapediatrics.2026.2567. https://jamanetwork.com/journals/jamapediatrics/fullarticle/2851913 (ClinicalTrials.gov NCT03649659)
  2. [2] University of Michigan (2026). Press release via ScienceDaily, 25 October 2026. https://www.sciencedaily.com/releases/2026/10/261025222339.htm
  3. [3] NIH Research Matters: Coating stops tooth decay in children. https://www.nih.gov/news-events/nih-research-matters/coating-stops-tooth-decay-children

Credits

Images via Wikimedia Commons (illustrative unless stated): Child receives dental care in a clinic with a smiling dentist.jpg (Shixart1985, CC BY 2.0); Smile - fluoride makes it so easy (4647272023).jpg (US National Library of Medicine, No restrictions); Pacific Partnership 2022 Dental Professionals visit Naha SDA Primary School (7404286).jpg (U.S. Navy, Public domain); Basic dental screening 150218-N-QK202-017.jpg (U.S. Navy, Public domain); BeforeAfterSDF.jpg (J. MacLean, T. Nelson, Y. Crystal, CC BY-SA 4.0). On-screen graphics: own.

AI voice note: the narration in the Short is an AI clone of my own voice (Chatterbox TTS by Resemble AI, MIT licence), used with my consent. I wrote the script and checked the figures against the sources above.

This page is general information, not medical or dental advice. Please talk to a doctor, dentist or pharmacist about your own health.