The single most powerful thing a parent can do for their child's lifelong oral health takes 60 seconds, twice a day, with the right toothpaste — and the second most powerful thing is to keep sugar at mealtimes rather than letting it drift through the day in a juice cup. Most decay in young children comes from the gap between knowing this and actually doing it consistently from the first tooth onward.
Healthbooq (healthbooq.com) covers child health in plain language, dentistry included.
How Teeth Come Through
The first baby tooth typically appears around 6 months — usually one of the lower central incisors. Wide variation is normal: some babies have a tooth at 4 months, some are still gummy at 12, and a small number of healthy babies do not cut their first tooth until 14 to 15 months. By around 2½ to 3 years old, the full 20-tooth set is in: 8 incisors at the front, 4 canines, and 8 molars at the back.
Teething itself is unpredictable. Some babies pass each tooth without anyone noticing; others drool by the bucket, gnaw on furniture, sleep poorly, and have a sore patch on the gum visible the day before the tooth breaks through. Mild grumpiness, increased dribble, a slightly raised temperature (but not above 38°C), and a flushed cheek on the side of the erupting tooth are all on the spectrum of normal.
What is not teething: a high fever, vomiting and diarrhoea, an unwell baby with a cough, or a rash that is more than perioral drool rash. Attributing those to teething is one of the more common reasons children's illnesses get missed. If the baby looks ill rather than uncomfortable, it is something else.
Things that genuinely help: a chilled (not frozen) teething ring, a clean cold flannel to gnaw on, gentle gum rubbing with a clean finger. Sugar-free teething gel from a pharmacy can take the edge off; teething necklaces (amber, silicone) are discouraged because of strangulation and choking risk. Paracetamol or ibuprofen at the right dose for age and weight is fine if a baby is genuinely miserable, not as a routine.
The Adult Teeth Surprise at Age 6
The first adult tooth shows up earlier than most parents expect — usually around 6, occasionally as early as 5½. It is the first permanent molar, and it erupts behind the last baby molar without pushing anything out, because it has no baby predecessor. Plenty of parents miss it for months and only notice when a dentist points it out at a check-up.
From there, baby teeth fall out in roughly the order they came in (front to back), and adult replacements follow underneath. By age 12 to 13, most children have 28 permanent teeth. Wisdom teeth, if they appear at all, come in much later — between 17 and 25, often a topic for a dentist appointment in late adolescence.
The Brushing That Actually Prevents Decay
NHS guidance on toothpaste, by age:
- Under 3 years: a smear of toothpaste containing at least 1,000 ppm fluoride.
- 3 to 6 years: a pea-sized blob, also at least 1,000 ppm fluoride.
- 7 and over: a pea-sized blob of standard adult toothpaste — 1,350 to 1,500 ppm fluoride.
The single piece of advice most parents miss: spit, don't rinse. After brushing, spit the foam out but do not chase it with a glass of water. The thin film of fluoride left on the enamel keeps working for hours; rinsing it off significantly reduces the protective effect. Same logic in reverse — no eating or drinking for half an hour after brushing.
Brush for two minutes, morning and last thing at night. Last thing at night matters: saliva flow drops while a child sleeps, so any sugar still on the teeth at bedtime gets a long, uninterrupted acid attack overnight.
A young child cannot brush thoroughly on their own. The realistic rule is: parent does the brushing until about 4, parent supervises and finishes off until about 7, and from 7 or 8 the child can do a competent job alone — but most children still benefit from a quick parental check, especially of the back molars, until 9 or 10.
Sugar: It's Frequency That Bites
Decay is acid damage. Bacteria on the teeth ferment sugar into acid, the acid pulls minerals out of the enamel, and given enough time and frequency, a hole forms. Each exposure to sugar produces 20 to 30 minutes of acid attack before saliva neutralises the mouth back to baseline.
Total sugar over the day matters less than how it is spread out. A piece of cake at the end of lunch — one acid attack. A juice cup sipped over two hours — many acid attacks. The same amount of sugar, very different damage.
Practical version of this rule:
- Sugary food and drink at mealtimes only. After-meal pudding is fine; afternoon-long juice is not.
- Plain water and milk between meals. Squashes, fruit juices, smoothies, flavoured milks, and fizzy drinks all count as sugary.
- No bottle or sippy cup of anything except water in the cot or buggy. Milk pooling against teeth overnight is a classic cause of severe early decay (so-called "bottle caries").
- "Sugar-free" gum and pastilles can be deceptive — many contain acidic sweeteners that erode enamel even without sugar.
NHS guidance caps free sugars at 19g/day for ages 4 to 6 and 24g/day for 7 to 10 — easy to exceed with a single sweetened yoghurt and a juice carton.
Fluoride Varnish at the Dentist
Twice-yearly fluoride varnish, painted onto the teeth by a dentist or hygienist, is one of the highest-evidence interventions in paediatric dentistry. NICE recommends it for all children from age 3, and from when the first tooth appears for higher-risk children (medical risk factors, family history of decay, deprivation, special needs). It takes a couple of minutes, dries quickly, and reduces decay meaningfully — even in children who already brush well.
The First Dental Visit
The NHS recommends a first dental visit as soon as the first tooth comes through. NHS dentistry is free for all under-18s in England (and full-time students up to 19). The first visit is mostly about the child seeing the chair, the light, and the dentist while nothing is wrong — sitting on a parent's lap, a quick look in the mouth, ten minutes and home. That early familiarity is how children grow up able to walk into a dentist's surgery without dread.
If you cannot find an NHS dentist in your area accepting new patients, persist — phone several practices, ask the GP, and use the NHS dental search rather than waiting for a problem to drive the first visit.
Common Problems Worth Knowing
- A baby tooth knocked out in a fall: do not re-implant it (it can damage the developing adult tooth underneath). Get the child seen by a dentist same-day, mostly to check the socket and the adult tooth bud.
- An adult tooth knocked out: time-critical. Pick it up by the crown (not the root), rinse briefly under cold water if dirty, and either replant it gently into the socket and bite onto a clean cloth, or store it in milk and head straight to a dentist or A&E. Re-implantation in the first hour has the best outcome.
- Teeth grinding (bruxism) at night: very common in young children, almost always settles by adolescence, rarely needs treatment unless teeth are visibly wearing or the child wakes with jaw pain.
- Tooth discolouration: brown stains can be early decay or extrinsic stain from supplements; a chalky white patch near the gum line is a sign of early demineralisation and is reversible if caught and brushed daily with proper fluoride.
- Thumb sucking: usually self-limiting and harmless before age 4; persistent past 6 or 7 can affect the bite, so it becomes worth gently helping a child stop.
The simple version of all of this: brush twice a day with fluoride toothpaste, spit don't rinse, keep sugar to mealtimes, and see a dentist regularly from the first tooth. Almost everything else falls into place from there.
Key Takeaways
Teething usually starts around 6 months, with the lower front teeth first; the full set of 20 baby teeth is in by about age 3. The first permanent molar surprises a lot of parents because it comes through behind the last baby molar at around age 6 — it is an addition, not a replacement. Decay is the most common chronic disease of UK childhood and the leading reason children have a general anaesthetic, yet it is almost completely preventable: brush twice daily with fluoride toothpaste, spit don't rinse, keep sugary food and drinks to mealtimes, and start dental visits at the first tooth (free on the NHS for all under-18s).
