Baby teeth are placeholders for the permanent teeth that will erupt in the future. If baby teeth are decayed and not treated, then they may become infected. An infected tooth is like any infection in the body and so it must be treated, and typically the only treatment at that point is to extract the baby tooth. If a baby tooth is extracted too early, then it often causes spacing problems as the teeth around the extracted tooth will shift and eliminate the space that is needed for the permanent tooth to erupt in the future. If a baby molar is extracted at age 6, it is very possible that the permanent tooth to replace the baby molar will not be ready to erupt until the child is age 12 or later, and most likely there will not be any space for that tooth to properly erupt by that time. We always recommend filling baby teeth that have cavities unless the child is likely to lose the tooth naturally in the near future. Very young children should always have their cavities filled to prevent pain, infection, and early loss of baby teeth.