Caps for milk teeth: Crowns are much more durable than fillings, and usually last until the baby tooth falls out. It is very important to repair and restore primary teeth. Although children begin to lose a few baby teeth by about six, they won't lose their baby molars until age 12 or 13. Do dentists cap baby teeth? If the cavity is still small, your pediatric dentist can fix the tooth with a small simple filling. However, if the decay has significantly damaged the tooth, it is often necessary to place a crown “cap” on the tooth.