Cavities are the unfavorable tiny holes in the teeth. Cavities develop because of acid buildup from food and drinks. Cavities usually form on the tip or in between teeth where food debris gets trapped. Cavities are white when still in their early stages. But when left untreated, these cavities turn into dark brown or black taints in the teeth. Cavities can lead to tooth sensitivity, severe pain, and infection in children’s teeth. Sometimes, children with cavities even lose their infected or decayed teeth.