Dental cavities affect between 60-90 percent of school-aged children, and the toothaches they cause are the most common reason that kids miss classes. Small cavities can be observed or treated with dental fillings. But larger cavities and cracked teeth may require more extensive treatment like dental crowns. A child’s back teeth or "molars" are the most used for chewing and the longest to stay in the mouth (usually til age 11-12). Keeping the molars in the mouth until they are ready to fall out is important because these baby teeth serve as the best placeholders for the adult teeth. It's important to treat baby teeth because any infection in them can spread to and damage the developing adult teeth under the gums. Dental crowns can be made of stainless steel, composite resin or zirconia, depending on each child's needs.