Liquid medications containing iron, such as supplemental vitamins given to infants, also can cause dark stains. Other causes of discoloration include:

• Certain antibiotics, such as tetracycline taken during pregnancy
• Jaundice in newborns, which may cause a yellow or greenish tint
• Excessive fluoride (fluorosis), which may cause bright white spots
• Injury to teeth, which may result in a pink or grayish tint
• Chronic illness or recurrent fevers
• Genetic problem with enamel formation

Proper dental care begins before your child's first tooth appears. Teeth actually start to form in the first trimester of pregnancy. At birth, a baby has 20 unerupted primary teeth. To prevent the buildup of bacteria in your baby's mouth, run a damp washcloth over your baby's gums after feedings. When your baby's first teeth appear — usually at about 6 months — start using a soft children's toothbrush twice a day. Children should have their first dentist appointment between the ages of 1 and 3 years depending on the child's oral hygiene, family dental history and appearance of erupting teeth.

Baby bottles can also create problems for your child's teeth. When liquids such as milk or juice stay in contact with the teeth for long periods, the sugars cause tooth decay. To prevent this:

• Don't put your baby to bed with a bottle, unless it contains plain water.
• Don't let your child walk around with a bottle during the day.
• Don't put sugared beverages, such as soft drinks or fruit drinks, in your baby's bottle.

Fortunately, normal permanent teeth often grow in to replace discolored baby teeth. Even if discoloration persists in permanent teeth, a dentist may be able to remove these stains. If you have concerns about your baby's teeth, talk to your baby's doctor. He or she may be able to refer you to a pediatric dentist.