Toddler Tooth Decay: How It Starts and How to Stop It
- Star Light Dental
- August 20, 2026
- [email protected]
About one in three Australian children has had decay in their baby teeth by the age of five or six, and dental treatment under general anaesthetic is one of the most common reasons young children are admitted to hospital. Almost all of it is preventable.
Decay in toddlers moves fast, because baby teeth have thinner enamel than adult teeth. The good news is that the early stage can be spotted at home and reversed.
1. How Decay Starts in Toddlers
The bacteria that cause decay are not present at birth. They are usually passed on from a parent or carer, through shared spoons, tasting food first or cleaning a dummy in your own mouth. Once they are established, every exposure to sugar gives them the fuel to produce acid.
In toddlers the classic pattern is decay on the upper front teeth, because that is where milk or juice pools when a child falls asleep with a bottle. At night, saliva flow drops and the teeth sit in it for hours.
2. Lift the Lip: a Check Every Parent Should Know
Once a month, lift your child’s top lip and look at the front teeth along the gumline.
- Chalky white lines or patches near the gum are the first sign of decay. At this stage it can still be reversed.
- Yellow or brown spots mean the enamel is breaking down.
- Holes, broken edges or a pimple on the gum mean it is advanced and needs treatment soon.
If you see any of these, book a visit. Do not wait for pain, because young children often cannot tell you that a tooth hurts. They may simply eat less, sleep badly or become irritable.
3. The Habits That Cause It
- going to bed with a bottle of milk, formula or juice
- sipping from a bottle or sippy cup of anything other than water through the day
- juice, cordial, flavoured milk and soft drinks
- frequent snacks of biscuits, muesli bars, fruit straps, dried fruit and sweet yoghurt pouches
- dummies dipped in honey or anything sweet
- no brushing, or brushing without toothpaste after 18 months
4. What to Do Instead
- Introduce a cup from around six months and aim to be off the bottle by about twelve months.
- Offer only water or plain milk to drink. Whole fruit is better than juice.
- Finish the last feed before the bedtime brush, not after it.
- Brush twice a day from the first tooth. Use water until 18 months, then a pea-sized amount of low-fluoride children’s toothpaste.
- Keep sweet foods to mealtimes rather than grazing.
- Do not share spoons or clean dummies in your own mouth, and keep your own teeth healthy.
Our baby teeth timeline covers care at every age.
5. Why Baby Teeth Are Worth Saving
It is tempting to think that decay in baby teeth does not matter because they fall out anyway. The back baby teeth stay until the age of ten to twelve. Untreated decay causes pain and infection, affects eating, sleep, speech and growth, and can damage the adult tooth forming underneath. Baby teeth lost early let the other teeth drift, which leads to crowding later. Children with decay in their baby teeth are also much more likely to have decay in their adult teeth.
6. How It Is Treated
Early white-spot decay can often be stopped and reversed with fluoride treatment, better brushing and changes to diet. Small cavities are filled. Badly broken-down back teeth may need a crown, and teeth that are infected may need to come out. Very young children who need a lot of treatment are sometimes referred to a specialist paediatric dentist, and treatment may be done under general anaesthetic in hospital.
Check-ups, fluoride treatments, fissure sealants, fillings and extractions are all covered for eligible children by the Child Dental Benefits Schedule.
First Visit by the First Birthday
The Australian Dental Association recommends a first dental visit when the first tooth appears, or by your child’s first birthday. Dr Liza Mekhael has a special focus on children’s dentistry, and Star Light Dental is a CDBS provider with Saturday appointments, parking at the door and access that suits prams. Call (02) 9432 2833 or book online.