Childhood Tooth Decay: Causes, First Signs and How to Prevent It

Decay needs three things: bacteria in plaque, sugar for them to feed on, and time. How often a child has sugar matters more than how much. Sipping a sweet drink, or a snack every hour, keeps the teeth under acid attack all day, while a sweet taken with a meal does less harm.

The pattern dentists see most in toddlers is decay of the upper front teeth, linked to a bottle or feed at night or through the day with milk, juice or a sweet drink, with no cleaning afterwards. Sweetened sipper cups, packaged drinks, biscuits and toffees count too. Honey or sugar on a dummy does harm.

Milk teeth have thinner enamel than adult teeth, so decay spreads faster once it starts.

Look at the upper front teeth, lifting the lip. The earliest sign is a dull white line or band along the gum edge. It looks like chalk and is easy to miss. Next it turns yellow or brown, and then small holes appear. A child may have no pain at all until the decay is deep.

Any white, brown or black spot, or a tooth that looks chipped, is worth a check. Pain, swelling of the gum or face, or a gum boil means infection and needs prompt care. Face swelling with fever, or trouble swallowing or breathing, means same-day care, and a hospital emergency if breathing or swallowing is affected. Our guide on cavities in milk teeth explains what treatment involves and why milk teeth still need it.

Begin cleaning as soon as the first tooth appears, twice a day, with a fluoride toothpaste in the amount a clinician or the label advises. Our guide on brushing children's teeth covers technique and amounts. Help with brushing until your child can do it well alone, and brush last thing at night.

Keep water as the only drink between meals and at night. Avoid putting a child to bed with a bottle of anything but water, and limit sweets to mealtimes. A dentist may recommend fluoride varnish, explained in fluoride treatment for children.

A first dental visit around the first birthday, or when the first tooth comes through, gives you advice for your child and catches early signs. See the kids dentistry page for more.