Is Fluoride Treatment Safe for Children?

Fluoride works on the surface of the tooth. It helps enamel take back minerals lost during acid attacks, makes the enamel more resistant to the next attack, and reduces the ability of plaque bacteria to make acid.

That is why it is the most widely recommended preventive measure in children's dentistry. It slows and sometimes reverses the earliest chalky stage of decay, before a hole has formed. It does not rescue a cavity that is already there. For that, see cavities in milk teeth.

It works best as a steady, low-level supply, from toothpaste twice a day, with a stronger professional dose at check-ups for children at higher risk.

Start when the first tooth comes through. Under about three years, a smear about the size of a grain of rice. From about three to six years, a pea-sized amount. Use a fluoride toothpaste suited to the child's age, and check the label.

An adult should put the toothpaste on the brush and do the brushing, or supervise closely, until the child is about seven or eight. Brush twice a day, once last thing at night.

Teach the child to spit, not swallow, and not to rinse with a lot of water afterwards. A thin film left on the teeth keeps working. Do not use adult mouthwash with fluoride in young children, who tend to swallow it. The age to start cleaning is in teething symptoms.

Fluoride varnish is a sticky coating painted onto the teeth in a minute or two. It sets on contact with saliva and releases fluoride slowly over the following hours and days. It involves no drilling and no injection, and a child can usually eat and drink soon afterwards, though the dentist will advise on softer food for the rest of the day.

It is usually advised every three to six months for children at higher risk of decay, for example after a first cavity, with a sugary diet, frequent snacking or deep grooves in the teeth, and less often for low-risk children.

It is one part of the preventive plan alongside pit and fissure sealants and diet changes. Our kids dentistry page sets out how these fit together at a check-up.

Too much fluoride while the permanent teeth are still forming under the gum, mostly below about eight years, can cause dental fluorosis. In its mild form it shows as faint white lines or flecks on the enamel. It is a cosmetic change, not a decay risk, and in mild cases is hard to notice.

Most cases come from swallowing toothpaste, using more than the pea-sized amount, or a high natural fluoride level in the drinking water. In some parts of India the groundwater is naturally high in fluoride. If you are unsure about your water, ask the dentist or a local water testing service before adding more fluoride.

Large amounts swallowed at once can cause stomach upset. Keep toothpaste out of reach, and if a child has swallowed a large amount, call a doctor or a poison helpline promptly.

It is not a licence for a sugary diet. The most useful single change for most families is fewer sugary snacks and drinks between meals, and nothing but water after the last brush at night.

It does not replace brushing technique, supervised cleaning, or regular check-ups. A child who has had a cavity may need more than fluoride, such as a first dental visit style review of feeding and cleaning habits.