Tooth decay in babies and toddlers

Breastfeeding to sleep or overnight does not mean your child will get tooth decay. 

Tooth decay is usually caused by several factors working together. The best way to protect your child’s teeth is to reduce sugar exposure, brush twice daily, use fluoride and see a dentist regularly.

Some things can make tooth decay more likely for young children:

• Sugar intake: Food and drinks with added sugars increase the risk of tooth decay.
• Poor oral hygiene: Teeth that aren’t cleaned regularly are more at risk. Dentists recommend cleaning twice a day.
• Less saliva: Saliva helps wash sugars from the teeth and reduce acidity. Saliva flow naturally drops during sleep and may also be lower if a child was born early, has other health conditions or takes some medicines.
• Weak enamel: Some children are born with weaker tooth enamel (the hard, protective outer layer) which can increase their risk of tooth decay.

You might have been told that breastfeeding to sleep or feeding overnight will harm your child’s teeth. This idea comes from a few places:

Research findings aren’t always clear
Studies on breastfeeding and tooth decay have had mixed results. It can be hard to separate early feeding habits from other important factors, like sugar in the diet and how teeth are cleaned.

Concerns about cleaning teeth
Whether they are breastfed or bottle fed, many babies feed until they are drowsy or asleep. This means their teeth are not being cleaned just before bed. And if they feed at night, you're unlikely to clean their teeth after each feed. This is a common concern but it's not easy to change, particularly in younger babies.

Not understanding how breastfeeding works
When a baby breastfeeds, the nipple is drawn to the back of their mouth and milk goes straight to their throat and is swallowed. When a baby falls asleep and stops sucking, the flow of milk stops. This means breastmilk doesn’t stay in the mouth and sit around the teeth.

This is very different from bottle feeding. Milk from a bottle can settle around the teeth, especially if a baby falls asleep with a bottle in their mouth. This explains why bottle feeding to sleep is linked with tooth decay.¹

You may have heard that feeding during the night causes tooth decay. Some studies describe a possible link between frequent night breastfeeding and early childhood caries, especially in older toddlers. 

However, these studies can’t always separate breastfeeding from other important factors, like sugar in the diet, formula use, how teeth are cleaned and fluoride exposure.

Night breastfeeds are normal and important. Feeding overnight helps babies to get enough milk and maintains your milk supply. You don’t need to stop breastfeeding at night to protect your child’s teeth. Instead, focus on cleaning your child’s teeth well before bed and in the morning and offering non-sugary foods and drinks during the day.

The research into breastfeeding and oral health is still evolving.

• Breastfeeding up to 12 months has been shown to protect against early childhood caries.² 
• Between 12 and 24 months, the evidence is less clear.
• Some studies, but not all, have found a higher risk of tooth decay with breastfeeding beyond 24 months, especially with frequent night feeding.^3,4
• Tooth decay is strongly linked to sugar intake and poor oral hygiene, and is less likely when children have fluoride (for example, in tap water or toothpaste).^5,6
• Breastfeeding is only one of many factors that can influence tooth decay risk. 
   

Bottom line:

When babies start eating other foods, especially those with added sugars, the risk of tooth decay increases. Good dental hygiene (like cleaning teeth) and healthy eating habits are the most important ways to protect your child’s teeth.

Breastmilk behaves differently from other drinks when it comes to teeth. Lab studies show it doesn’t weaken tooth enamel in the way that other milks do.⁷ Breastfeeding also keeps the pH (acidity) of the mouth within a healthy range and limits the growth of harmful bacteria.^8,9 

While scientists are still learning how breastmilk affects the mouth, we do know that tooth decay is more strongly linked to frequent sugar exposure, poor oral hygiene, and other health factors – not breastmilk.

• Breastfeed your child for as long as you both want. 
• If breastfeeding your child to sleep works for you,  you can continue to do this. 
• Clean your child’s teeth carefully twice a day, from the time they first appear.
• Offer fluoridated tap water if available.
• Use fluoridated toothpaste from 18 months of age. If your mains water isn't fluoridated, ask your child's dentist if you should start earlier.
• Avoid sugary foods and drinks.
• Take your child for regular dental check-ups.

Looking after your baby or child's teeth - Healthdirect

Caring for your child’s teeth - Australian Dental Association (NSW Branch)