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How Breast Milk and Formula Impact Baby Teeth

Preventive steps to keep your family’s smallest smiles healthy

Published on: December 30, 2022

Close up of a baby with a bottle in their mouth

Editor's note: This article was provided by Delta Dental of Washington.

Primary teeth come in when babies are about 6 months old. However, parents can get a jump on their little one’s oral health before their first teeth even pop up.

“Newborn infants typically produce less saliva,” says Kyle Dosch, DDS, dental director of Delta Dental of Washington and a member dentist. “Saliva helps us wash away food debris and bacteria buildup in our mouth. For a newborn with less saliva, this process just doesn’t work as well.”

For babies, the bacteria in their mouths feed on the sugar and carbs found in breast milk and formula. The bacteria create an acid that wears away tooth enamel. When breast milk or formula stays in a baby’s mouth for too long, over time, this acid can lead to cavities and tooth decay. These small tips can make a big difference for your baby’s health over the long term.

  • Feeding and teething items, such as bottles, pacifiers and toys, are best used when cleaned and sterilized. Cavity-causing bacteria can be passed from caregiver to child through saliva. Avoid sharing utensils and don’t test the temperature of a bottle with your mouth to avoid transmitting bacteria from your own mouth to your baby’s.
  • Don’t put your child to bed with a bottle of breast milk or formula. When your child sips on breast milk or formula throughout the night, the sugars stay in their mouth, exposing their teeth to long periods of acid buildup from their mouth bacteria.
  • When baby’s teeth start to come in, have some clean, chilled teething rings on hand to soothe their gums.
  • Once a baby tooth comes in, begin your baby’s brushing routine by brushing with a soft-bristled toothbrush with a smear of fluoride toothpaste until age 2, and then a pea-size dot of toothpaste after age 2.
  • Take your baby to a dentist by their first birthday to spot early dental health problems and to get your child used to visiting the dentist.

Breastfeeding, also known as chestfeeding, can help with baby’s oral health as well as their overall health. Several studies found that babies who were breastfed only for their first six months had fewer teeth alignment issues in comparison with those who breastfed for less time or didn’t breastfeed at all. This is not to say breastfeeding is a guarantee for perfectly straight teeth — every child is different, and factors such as genetics and pacifier use may affect alignment as well.

Another healthy option is bottle feeding. However, it is important that children eat in one feeding. Don’t leave children with bottles for extended periods of time, as this can feed bacteria that create cavity-causing acid. Never give a child a bottle with juice unless recommended by a doctor.

Formula comes in three different types in the United States, each with varying levels of fluoride, a natural mineral extremely important in maintaining a healthy smile. Fluoride strengthens and protects teeth, but too much fluoride can cause dental fluorosis — changing the tooth enamel and appearing as faint white streaks on the teeth.

The American Dental Association recommends that if liquid concentrate or powdered infant formula is the primary source of nutrition, it be mixed with water that is fluoride-free or contains low levels of fluoride to reduce the risk of fluorosis.

Ready-to-feed formula has very little fluoride in it and will not cause dental fluorosis. Powdered and liquid concentrate may increase the chance of cosmetic dental fluorosis when mixed with fluoridated water.

Consult your pediatric dentist or medical care provider if you have questions or to help determine the right amount of fluoride for your child and what formula will work best for your needs.

For more information on dental health for both you and baby, visit Delta Dental of Washington’s blog

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