If your child has a cavity, it can compromise their oral health, and leave them with a lingering toothache. Dental fillings are one of the fastest, simplest, and most affordable ways to treat cavities for kids. Cavities are a big deal, even if they're only present in the baby teeth. Cavities can cause pain and discomfort and may lead to infection. Baby teeth are just as important as your child’s adult teeth since they help to map the paths that adult teeth follow when they emerge later in life.