Decay in children moves faster than in adults, because the enamel on a baby tooth is thinner and the nerve chamber inside it is proportionally larger. A cavity that would take years to become serious in an adult tooth can reach the nerve in months.
The good news is that the earliest stage is reversible, and that stage is visible if you know what to look for.
What it looks like, stage by stage
White spots — reversible
Chalky white marks, usually along the gum line, most often on the upper front teeth. They are easiest to see when the tooth is dried. This is mineral being lost from the enamel surface, and at this point it can genuinely be reversed with fluoride and better plaque control. No drilling is needed.
Most parents do not know this stage exists, which is why it is usually missed.
Brown or dark marks — a cavity has formed
The surface has broken down. This needs restoring; it will not recover.
Visible holes, or a tooth breaking down
More advanced, and often still painless at this point — which is why parents assume it cannot be serious.
Pain, swelling, or a gum boil
The nerve is involved or the tooth is infected. A small bump on the gum near a tooth is a draining abscess and needs seeing promptly.
Pain is a late sign, not an early one. A child with no pain may still have several cavities.
Where it starts
Two patterns dominate. In toddlers, the upper front teeth just under the lip — typically associated with bottles, sipping cups and night feeding, and hidden from view precisely because of where it is. In older children, the biting surfaces of the back molars, where the deep grooves trap food and a brush cannot reach the bottom of them.
The first permanent molars, arriving around age six at the back, are the single most commonly decayed teeth in childhood — and many parents do not realise they are permanent at all.
Why it happens
Bacteria in plaque produce acid when they are fed sugar, and that acid dissolves mineral out of the enamel. Saliva repairs the damage between attacks, which is why frequency matters more than quantity.
A whole chocolate bar eaten in five minutes at the end of a meal causes one acid attack. The same chocolate eaten square by square across an afternoon causes a dozen, with no recovery time between them. A juice cup carried around and sipped all morning is worse than juice drunk with lunch.
This is the single most useful thing for a parent to understand, because it means the change required is about when rather than about banning things.
How it is treated
Early white spots
Fluoride varnish, improved brushing with fluoride toothpaste, and dietary change. Monitored at intervals. No drilling.
Small to moderate cavities
A filling, adapted to a child — the technique, the materials and the appointment length all differ from adult treatment.
Large cavities in back teeth
Where too much of the tooth has gone for a filling to hold, a preformed crown is fitted over the whole tooth. It looks unusual but it is durable and it saves the tooth until it is due to be lost naturally, which protects the space for the permanent tooth.
When the nerve is involved
A pulp treatment adapted for baby teeth, followed by a crown, keeps the tooth in place. This is preferable to extraction because of the space issue — see why baby teeth matter.
Extraction
A last resort, used when the tooth cannot be saved. A space maintainer is often fitted afterwards to stop the neighbouring teeth drifting.
What actually reduces the risk
- Brush twice a day with fluoride toothpaste, and do it for them or after them until around seven or eight — see teaching children to brush properly.
- Brush last thing at night and spit, do not rinse, so the fluoride stays on the teeth.
- Keep sugar to mealtimes. Frequency, not quantity.
- Water or milk between meals, not juice or squash.
- No bottle in bed with anything but water — see preventing early childhood decay.
- Check medicines. Many children’s syrups are sweetened; sugar-free versions often exist, and long-term nightly medicine is a genuine risk factor.
- Sealants on the permanent molars when they arrive.
- Fluoride varnish at check-ups, where appropriate — see fluoride and children’s teeth.
Frequently asked questions
My child has no pain. Can there still be decay?
Yes, frequently. Pain is a late symptom. This is what check-ups are for.
Can white spots really be reversed?
Early ones, yes — with fluoride and better plaque control. Once the surface has broken down, no.
Is decay hereditary?
Susceptibility varies, and enamel quality can be affected by illness during tooth formation. But the dominant factors are diet frequency, plaque and fluoride, all of which are modifiable.
Is my child’s toothpaste right?
Fluoride content and the amount used are both age-dependent. Bring the tube to your next appointment and ask.
My child fights brushing. What do I do?
It is extremely common. Consistency matters more than perfection, and there are practical techniques that help — ask us to show you.
Have it looked at before it hurts
Most decay in children is found at a routine check-up long before there is pain. See our pediatric dentistry page, or book an appointment.
To arrange a consultation at our clinic on Abbas El-Akkad in Nasr City, call +20 101 969 7597 or message us on WhatsApp.
