Researchers analyzed 15 randomized studies comparing the use of fluoride varnish in children 6 years and under. They found evidence that fluoride varnish does reduce the incidence of cavities. The 15 studies compared 5,002 children who received teeth varnish with 4705 children who did not. Most of the studies followed children over a two year period, while remaining lasted three years. The combined results showed a 10% reduction in cavities, as well as the halting the progression of cavities.