Tooth decay is the single most common chronic illness in UK childhood — around a quarter of 5-year-olds have visible decay, and it is the leading cause of hospital admission in 5-to-9-year-olds (mostly for tooth extractions under general anaesthetic). Almost all of it is preventable, and the prevention is straightforward enough to fit on a postcard. The first two years are when the habits stick.
Healthbooq covers infant and child health, including oral care from the first tooth.
When to Start
The first tooth usually appears between 6 and 10 months, though anywhere from 4 to 14 months is normal. Brushing starts the day it comes through — not when "there are a few more." Every erupted tooth surface is a possible decay site, and bacteria colonise the new tooth within days.
You don't need to do anything special before the first tooth. A clean finger or a soft cloth wiping the gums after feeds is fine if you want to, but it isn't essential. The starting gun is the first tooth.
The Toothpaste That Actually Protects
This is where the most common mistake happens. The "low-fluoride baby toothpastes" still on supermarket shelves provide inadequate protection. Current NHS and NICE guidance is:
- At least 1,000 ppm fluoride from the first tooth onward
- Family toothpaste (1,350 to 1,500 ppm) is appropriate from day one — you don't need a separate "baby" version
- Under age 3: a smear of toothpaste — about the size of a grain of rice
- Age 3 to 6: a pea-sized amount
- Age 7 and up: as for adults
The amount matters because most of the safety concern about fluoride in young children is about swallowing a lot of toothpaste, not the concentration itself. A smear contains too little fluoride for that to be a problem; a 1,000 ppm "baby" toothpaste used in a bigger blob does not protect the teeth as well as a 1,500 ppm family toothpaste used as a smear.
How to Actually Brush a Reluctant Baby
This is the part the guidance leaflets skip. A few things that help:
Position. Sit them on your lap or stand them in front of you with their head tilted slightly back resting on your forearm. You can see all the surfaces and they can't lurch sideways.
Two minutes is the goal but not the threshold. Any decent brushing beats none. Don't fight to two minutes if it turns the whole event into a battle — fight to "every surface, every day, twice."
Make it predictable. Same time, same place, same order — top right to top left, then bottom right to bottom left. Predictability beats novelty.
Lying down on a changing mat works for some babies under 1 — it's the same position as a nappy change, and they tolerate it.
Brush their teeth, not their hands holding the brush. Children under about 7 don't have the dexterity to clean their own teeth properly, even when they've been doing it for years. Let them have a go first if they like, then take over and do the actual cleaning.
Distraction tricks that work: counting teeth out loud, singing a song, mirror in front of them, second toothbrush they hold while you use the working one.
Twice a Day — and the Bedtime One Matters Most
The two recommended times are first thing in the morning and last thing at night. The bedtime brush is the more important of the two, because:
- Saliva flow drops dramatically during sleep
- Saliva is what neutralises the acid bacteria produce
- A mouth full of food residue going into a low-saliva 8-hour window is exactly the worst combination
After the bedtime brush: nothing else to eat or drink, and spit, don't rinse. Rinsing washes away the fluoride that's been left on the tooth surface to keep working overnight. This is one of the few free, evidence-based wins in dental care, and almost everyone gets it wrong.
The Diet Side: Frequency Beats Amount
Sugar is the food source for the bacteria (mostly Streptococcus mutans) that produce the acid that demineralises teeth. The number that matters is how often sugar reaches the teeth, not how much in total.
A useful rule of thumb: each sugar exposure starts a 20–30 minute "acid attack" on the enamel. Six small sugary snacks throughout the day is six acid attacks. The same total sugar in two sittings is two acid attacks.
Practical implications:
- Free sugars (added sugar, fruit juice, honey, syrup): avoid in babies under 1, per NICE
- Fruit juice or smoothies — if given at all, water it down (1 part juice to 10 parts water), give at mealtimes only, and from a cup not a bottle
- Snacks — savoury, fruit (whole, not pureed), or cheese between meals
- Sweets and chocolate, when they appear, are better at the end of a meal than in the middle of the afternoon
Cheese after a sugary food is genuinely useful — it raises mouth pH back toward neutral.
The Single Most Important Diet Change: No More Bottles in Bed
If your baby goes to sleep with a bottle of milk, juice, or formula, that liquid sits against the upper front teeth for hours, with bacteria converting the lactose or sugar to acid all night. This produces a recognisable pattern called early childhood caries (or "nursing bottle caries"): the upper four front teeth go brown and crumble, often before the second birthday.
Once the first tooth is through:
- Stop the bedtime bottle. Last milk feed before bedtime, awake, in a chair. Then teeth-brushing. Then bed.
- Move milk to a free-flow cup during the day — sippy cups with valves keep liquid against the teeth longer; an open or free-flow cup is better.
- Water only if a drink is genuinely needed in the night.
This single change is one of the highest-yield dental interventions in early childhood, and it is also one of the hardest, because the bottle is often a sleep cue. The night-bottle-to-cup transition usually takes a week or two of disrupted sleep before the new pattern settles.
First Dental Visit
The NHS recommends the first dental visit within 6 months of the first tooth, or by the first birthday at latest. NHS dental care is free for children in the UK; you do not need a separate appointment "to register" before this.
What the first visit looks like:
- A look around the mouth (often on the parent's lap)
- A chat about diet and brushing
- Sometimes a first fluoride varnish application (a few seconds of painted-on coating, 2 to 6 times a year)
If your child has had no exposure to a dentist, normalising the environment in the first year — going with you to your appointment, sitting in the chair without anything happening — pays off enormously by the first proper visit.
Fluoride Varnish
Fluoride varnish is painted on by a dentist or trained dental nurse and adds a strong concentration of fluoride at the tooth surface. NICE recommends it:
- From age 3 for all children, twice yearly
- From age 2 for higher-risk children (family history of decay, lower oxygen-deprived areas, special diets, or visible early decay already)
Varnish is quick (under a minute), well-tolerated, and one of the more cost-effective preventive dental measures in routine NHS practice.
Teething Pain Is Real, But Not the Reason for a Fever
Genuine teething symptoms: irritability, drooling, gum redness, cheek flushing, mild low-grade temperature (under 38°C), wanting to chew on cold things. Not caused by teething: high fever (≥38°C), diarrhoea, vomiting, rashes that aren't on the cheeks. If a baby is genuinely unwell, look for an actual illness rather than blaming teeth.
What helps:
- Cold teething rings from the fridge (not the freezer — too hard, can damage gums)
- A cold, wet flannel to chew on
- Paracetamol or ibuprofen at age-appropriate dose for genuine distress
What to avoid:
- Teething gels with lidocaine or salicylates — MHRA advised against these for under-2s; risk doesn't justify the marginal benefit
- Amber teething necklaces — no evidence of effect, real choking and strangulation risk
- Teething biscuits with sugar — the worst possible combination
Sippy Cups and Bottles After 12 Months
NHS guidance is to move from bottle to cup by 12 months. Free-flow open or training cups (no valve) are better than sippy cups for both speech development and dental health. Long-term sippy-cup use, especially with juice or milk, prolongs the same dental-acid exposure that the bottle did.
When to See a Dentist Urgently
- A tooth knocked out (a permanent tooth — same-day reimplantation matters; for a baby tooth, it's not reimplanted but should still be assessed)
- A tooth knocked loose
- Visible brown or white spots developing on teeth
- Persistent pain in or around the teeth
- A swollen face or gum, especially with fever
Most other concerns can wait for a routine visit — but the earlier any visible decay is caught, the more likely it can be managed without an extraction.
Key Takeaways
Start brushing the day the first tooth comes through. Use a smear of family fluoride toothpaste — at least 1,000 ppm fluoride; the NHS no longer recommends low-fluoride 'baby' toothpastes because they don't protect well enough. Twice a day, and the bedtime brush is the one that matters most. After brushing at night: spit, don't rinse. The biggest preventable cause of toddler tooth decay is a bottle of milk or juice in bed — stop it once teeth come through. First dental visit within 6 months of the first tooth, or by the first birthday at latest. NHS dental care is free for children.
