The document discusses dental caries (cavities) in children. It states that bacteria in the mouth use leftover food after meals to produce acid, which causes damage to teeth and leads to cavities. Brushing teeth after eating with toothpaste and dental floss removes food and bacteria, protecting dental health. The World Health Organization recommends that by age 12, a child should have no more than 3 cavities, but in Brazil, children of that age have over 6 cavities on average. The main ways to prevent cavities are brushing after meals, limiting sweets, and regular dental checkups.