Tooth decay is the most common reason children aged five to nine are admitted to hospital in England. Many of those admissions involve extractions under general anaesthetic for very young children. This is not inevitable. The factors that lead to it are largely preventable, and the foundations are established in the first years of life.
Baby teeth are not disposable. They hold space for permanent teeth, are needed for eating and speech, and can cause significant pain and infection when they decay. Looking after them matters from the moment the first one appears.
Healthbooq (healthbooq.com) covers health and care topics through the early years, including practical guidance on feeding, hygiene, and development.
When Teeth Appear
The timing of the first tooth varies widely and both ends of the range are normal. Some babies get their first tooth at four months. Others reach their first birthday with bare gums. The average is around six months, but there is no clinical concern until around 12 to 18 months in the absence of any teeth.
The lower central incisors usually come first. By the time a child is two and a half to three years old, most will have all 20 primary teeth. The exact sequence varies, and gaps and out-of-order eruptions are common and usually nothing to worry about.
Teething causes gum soreness and increased drooling. The traditional belief that it causes fever, diarrhoea, and respiratory symptoms is not supported by good evidence. If a teething child has a fever, something else is causing it and it is worth investigating.
Starting to Brush
Brushing should begin with the first tooth. Use a soft baby toothbrush and a smear (no bigger than a grain of rice) of fluoride toothpaste. NHS guidance is that children under three should use toothpaste containing at least 1,000 parts per million (ppm) of fluoride. Most children's toothpastes in the UK contain this or more.
From age three to six, use a pea-sized amount of toothpaste. From age seven, children can move to standard adult fluoride toothpaste if they can manage without swallowing it.
Spit, do not rinse. Rinsing after brushing washes away the fluoride that is doing the protective work. This is a change from what many parents were taught and it is counterintuitive, but the evidence is clear: leaving the toothpaste residue on the teeth provides ongoing protection.
Brush twice a day. The nighttime brush is the most important one: the mouth is dry during sleep, which removes one of the defences against acid attack. Brushing before bed and then giving nothing except water afterwards is the single most effective daily habit for preventing decay.
Getting a toddler to accept tooth brushing is a real challenge. Helpful strategies include making it part of a consistent routine rather than a negotiation, letting the child hold a spare brush and feel in control, and taking turns (the child brushes your teeth, then you brush theirs). Supervised and assisted brushing needs to continue until at least age seven, because children do not have the fine motor control to brush effectively on their own before then.
Fluoride and Safety
Fluoride hardens tooth enamel and makes it more resistant to acid attack. At the doses in toothpaste it is safe and effective. The concern some parents have relates to fluorosis, which are white or brown marks on the enamel caused by ingesting too much fluoride during tooth development. Using a smear for under-threes and a pea-sized amount from three to six keeps ingestion within safe limits even if some is swallowed.
In some parts of the UK, water is fluoridated at low levels as a public health measure. In non-fluoridated areas, toothpaste is the main source of protective fluoride for most children.
Sugar and Decay
Tooth decay is caused by acid produced when bacteria in the mouth feed on sugars. The bacteria are present in everyone's mouth. The variable is the sugar supply.
Frequency matters more than quantity. A child who eats one biscuit at breakfast has one acid attack on their teeth. A child who grazes on biscuits throughout the morning has multiple acid attacks with no recovery time between them. The teeth need periods without sugar to allow the saliva to neutralise acid and allow remineralisation of the enamel. Three or four eating occasions per day is better for dental health than continuous snacking.
Free sugars are the most damaging: these are sugars added to foods, plus natural sugars in fruit juice, honey, and syrups. The sugars in whole fruit are less damaging because they are contained within the fibre of the fruit and released slowly. Fruit juice, even unsweetened, is acidic and sugary and should be limited: NHS guidance recommends that under-fives have no more than 150ml of unsweetened fruit juice per day, and that it is served with meals rather than as a between-meal drink.
Milk and water are the recommended drinks for young children. Formula and breast milk both contain lactose, which is fermentable, but they are not a major cause of decay in children who are not fed continuously through the night.
Putting a baby to bed with a bottle of formula, juice, or any sweetened drink causes a specific pattern of decay in the upper front teeth sometimes called nursing bottle caries. It is avoidable.
The First Dental Visit
NHS guidance is to take a child to the dentist as soon as the first tooth appears. This is earlier than many families realise. The purpose of the first visit is not treatment but to get the child used to the environment, to allow the dentist to check the teeth and gums, and to give parents advice on brushing and diet.
NHS dental care is free for all children under 18. Dental practices accepting NHS patients can be found at nhs.uk. Some areas also have dental access services for children who have not been registered with a practice.
Going to the dentist regularly from infancy helps prevent dental anxiety developing. Children who have only ever had positive or neutral dental experiences are far less likely to develop the avoidance that complicates adult dental care.
Key Takeaways
Baby teeth matter and tooth decay in young children is the leading cause of hospital admission for children aged five to nine in England. Brushing should start with the first tooth, using a smear of fluoride toothpaste for children under three and a pea-sized amount from three onwards. Children should not eat or drink after brushing at night. The first dental visit should happen as soon as the first tooth appears, and NHS dental care is free for children under 18. Sugar frequency, not quantity, is the main driver of decay, meaning sugary drinks and snacks spread throughout the day are more damaging than one portion at mealtimes.
