Teeth - Tooth development

Disclaimer: This fact sheet is for education purposes only. Please consult with your doctor or other health professional to make sure this information is right for your child.

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Before birth

Your baby's first teeth (primary teeth) begin to form in the 16th week of pregnancy. They are almost completely formed in the gums at birth.

The strength of the primary teeth depends on the mother's health and diet during pregnancy. Pregnant mothers need to eat a well-balanced diet. A good diet will give the developing baby the right amount of fluoride.

Primary or 'baby' teeth

The primary teeth begin to come through the gums when your child is about six months old, but this can vary from infant to infant. There are twenty of these teeth. It is important to care for teeth properly from the start. If your child's diet contains too much sugar your child may have problems with both their gums and teeth.

Second teeth (permanent teeth)

The permanent back teeth begin to come through at about six years of age. These are sometimes called the 'six-year-old molars'. They come up behind the primary molars. The permanent front teeth also begin to come through at about six years of age.

All permanent teeth are important and a lot of care should be taken to keep them free from decay.


Fluoride is important for healthy teeth. Most water supplies have fluoride added. However, some rural areas may not have fluoride added to the water supply. If you live in a rural area you should check with your local council.

If your water has no fluoride in it

You may need to add fluoride to your child's diet after one year of age. Ask your dentist for advice. Breast-fed or bottle-fed babies (one year - four years) need at least 250ml of fluoridated water every day (about one cup) to get the right amount of fluoride. This may include water added to your baby's bottle. Older children need to drink more.


Many babies have no trouble when teeth come through the gums. Other babies get very upset. They might sleep badly, have red cheeks, be fussy and eat less. Their gums might look swollen and sore. They may have slightly loose bowel motions. Your teething baby needs extra comfort. Be patient and loving. Rubbing the gums with ice can help. If your child is in pain, ask your Dentist, Doctor, Child and Family Health Nurse, or Chemist for advice on what to give.

Bedtime bottles may cause problems

Baby's bedtime bottle of juice, cordial, flavoured drink, or even milk or formula, can lead to tooth decay. Bacteria in the mouth can use these sweet drinks to decay the teeth while your child sleeps. If your baby needs a bottle to go to sleep, fill it with water only. 


The Children's Hospital at Westmead
Sydney Children's Hospital, Randwick
Hunter New England Kids Health

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