Tooth decay is one of the most common chronic health problems in children. Cavities can cause pain, infections and difficulties with eating, sleeping and attending school, especially when decay begins early and progresses quickly.

A large clinical trial now suggests that a topical treatment called silver diamine fluoride may offer a simple way to stop some cavities from getting worse.

Why Cavities Keep Growing

Cavities begin when bacteria in dental plaque break down sugars and starches from food and drinks. During this process, the bacteria produce acids that gradually weaken enamel, the hard outer layer of the tooth.

If this continues, the enamel can break down enough to form a cavity. Silver diamine fluoride is applied directly to the affected area. It works in two important ways: the silver component helps reduce acid-producing bacteria, while fluoride supports the hardening of damaged tooth structure.

Because the liquid can be applied quickly without drilling, it may be particularly useful for young children who find conventional dental treatment difficult.

830 Children Took Part

Researchers led by Dr. Margherita Fontana at the University of Michigan School of Dentistry tested the treatment in children with severe early childhood tooth decay. The clinical trial included 830 children between one and six years old. Each child had severe early childhood caries and at least one cavity.

Participants received either silver diamine fluoride or a placebo at the beginning of the study and again six months later. Dental examinations were carried out at the start, then after three, six and eight months.

Decay Stopped More Often

The results showed a substantial difference between the two groups.

More than half of the cavities treated with silver diamine fluoride showed no further progression during the study period. Among cavities in the placebo group, only around 20% stopped progressing. Overall, the treatment arrested decay at more than twice the rate seen with placebo. This suggests that silver diamine fluoride can be effective at slowing or stopping active cavities in very young children. However, the treatment did not eliminate every problem.

Researchers found no meaningful difference between the groups in rates of dental pain.

There Is One Visible Trade-Off

Silver diamine fluoride permanently darkens the decayed part of the tooth.

That cosmetic effect is important for families to know about before treatment. In the children studied, the affected teeth were primary teeth, which eventually fall out naturally. For many families, preventing a cavity from worsening may outweigh the appearance change, particularly when the alternative could involve more complex dental treatment.

Why This Could Matter

One practical advantage is how easy the coating is to apply. Because young children often see pediatricians more frequently than dentists, researchers suggest that other trained healthcare professionals could potentially help identify early decay and deliver treatment in appropriate settings.

Fontana has emphasized that strong clinical evidence is essential before expanding access to this type of care. Based on the trial results, she described the treatment as both effective and well tolerated even in children as young as one.

The findings do not mean that silver diamine fluoride replaces brushing, fluoride toothpaste or regular dental care.

Instead, it may become an additional tool for children with severe early cavities, particularly when conventional treatment is difficult or delayed.

For parents, the main message is simple: early dental decay is worth treating quickly. A small cavity is much easier to manage before it becomes a source of pain, infection or more invasive procedures.