Your child's teeth can develop cavities as soon as they come in, if proper care isn't taken. Nursing bottle caries (care-ees), or cavities, can form when a child falls asleep with a bottle of milk, formula, or juice still in the mouth. The sugar in these liquids turns into acid, and remains in the mouth. These acids erode the teeth, causing decay. Newly formed teeth are very susceptible to decay because they haven't formed hard, protective enamel yet. The first sign of nursing bottle decay is often white spots on the teeth. A common place for this type of caries is on the tongue side of the tooth. The simplest way to prevent this type of cavity is to avoid giving a child anything but water in the nighttime bottle. Weaning a child from a milk bottle at bedtime may cause the child to fuss a little, but soon this new habit will replace the old one. Be sure to remove any bottle from your child's mouth as soon as he or she falls asleep.