Hearing that a young child has a cavity can quickly lead to worries about drilling, injections, sedation, or even hospital-based dental treatment. A large new clinical trial offers parents another option worth discussing with their child’s dentist: silver diamine fluoride, often called SDF.
SDF is a liquid that a dental professional paints directly onto a cavity. The application is quick and does not require drilling. It can harden decayed tissue and help keep some cavities from becoming larger—but it does not work for every tooth, and it comes with an important cosmetic tradeoff.
What the new study found
The 2026 randomized clinical trial published in JAMA Pediatrics enrolled 830 generally healthy children ages 1–6 who had severe early childhood caries. Children received either 38% SDF or a placebo. Treatment was applied at the beginning of the study and again after six months.
At six months, after the first application, SDF had arrested 54% of the treated cavities, compared with 22.5% in the placebo group. In other words, the decay had stopped progressing in slightly more than half of the SDF-treated lesions—but not in all of them.
The researchers did not find a difference in dental pain between the groups. About 30% of enrolled children did not complete the study, partly because data collection overlapped with the COVID-19 pandemic. Most reported adverse events were mild or moderate, and treatment-related events occurred at similar rates in the SDF and placebo groups.
What SDF does—and does not do
SDF arrests decay; it does not rebuild the missing part of a tooth. The cavity’s opening remains. Some teeth may later require a filling, crown, extraction, or another treatment to restore their shape and function.
The most noticeable drawback is that SDF permanently turns the treated decayed area dark brown or black. Healthy tooth structure generally is not stained in the same way, but the darkened cavity can be very visible, especially on a front tooth. Parents should see photographs and discuss the appearance before consenting.
SDF is currently cleared by the U.S. Food and Drug Administration for treating tooth sensitivity. Dentists commonly use it off-label to arrest cavities. The new trial was designed partly to supply evidence for formal regulatory consideration of that use.
Who might benefit?
The American Academy of Pediatric Dentistry supports SDF as part of an individualized cavity-management plan. A dentist might consider it for a very young or anxious child, a child who cannot comfortably complete conventional treatment, or when more extensive care must be delayed.
SDF must be applied by an appropriately trained professional. It is not a home remedy, and a parent should never purchase a dental chemical online and attempt to apply it.
Questions to ask your child’s dentist
Ask: “Is SDF appropriate for this particular tooth?” “How likely is it to arrest this cavity?” “How dark will the tooth become?” “Will my child still need a filling or crown?” “How often should it be reapplied?” and “What are the alternatives?”
SDF also does not replace prevention. The AAPD continues to recommend brushing children’s teeth twice daily with an age-appropriate amount of fluoride toothpaste, along with regular professional dental care and individualized guidance about diet and cavity risk.
The Good News for Parents
A cavity does not always mean that drilling must happen immediately. For some children and some teeth, SDF may provide a quick, low-cost way to slow or stop decay while avoiding—or postponing—more invasive treatment. It is not a perfect solution, but it gives families another evidence-based option to discuss with a dentist.
Sources & Further Reading
Fontana et al. (2026): Efficacy of Silver Diamine Fluoride in Young Children With Severe Early Childhood Caries
National Institutes of Health: Coating Stops Tooth Decay in Children
American Dental Association: Silver Diamine Fluoride
American Academy of Pediatrics: Silver Diamine Fluoride to Stop Tooth Decay
American Academy of Pediatric Dentistry: Policy on Use of Fluoride
