Understanding Dental Decay in Children – A Parent’s Guide

Understanding Dental Decay in Children – A Parent’s Guide

28/10/2025

Tooth decay (also known as dental caries) is one of the most common health problems in children, yet it’s almost entirely preventable.

In the UK, around 1 in 4 five-year-olds have obvious dental decay, and tooth extraction under general anaesthetic remains the most common reason for hospital admissions among children aged 6–10 years.

So what exactly causes decay, and what can you do as a parent to protect your child’s smile?

What Causes Dental Decay?

Dental decay happens when the natural bacteria in the mouth feed on sugars from food and drinks. When bacteria break down these sugars, they produce acids that attack the enamel (the hard outer layer of teeth). Over time, repeated acid attacks cause holes—known as cavities. The key factors are often referred to as the “decay triangle”:

1. Sugar – how often and how much is consumed.

2. Bacteria – naturally present in the mouth.

3. Time – repeated exposure over the day gives acids longer to attack teeth.

Children are especially vulnerable because their enamel is thinner and less resistant to acid than adult enamel.

Common Risk Factors in the UK

• Frequent snacking: Grazing on biscuits, crisps, or sweets throughout the day keeps sugar levels high in the mouth.
• Sugary drinks: Squash, fizzy drinks, flavoured water, and even fruit juices contain free sugars that increase risk. In the UK, it’s recommended that children have no more than 150ml of fruit juice or smoothie a day, and ideally with a meal.
• Bottle feeding at night: Giving milk or juice in a bottle at bedtime can leave sugar pooling around teeth overnight.
• Limited access to NHS dentists: Missed dental check-ups can delay the early detection of problems.

Tips to Reduce the Risk of Decay

Make Smart Food & Drink Choices

• Keep sugary foods and drinks to mealtimes only.
• Choose water and plain milk as the go-to drinks.
• Offer healthy snacks such as cheese, fruit, vegetable sticks, or rice cakes.

Brush Effectively

• Brush twice a day with fluoride toothpaste (at least 1,000 ppm fluoride for under-6s, and 1,350–1,500 ppm for over-6s).
• Supervise brushing until at least age 7.
• Use a pea-sized amount for children over 3; a smear for under-3s.

• Register your child with a dentist early—ideally before their first birthday.
• NHS dental care for children is free in the UK.

• Remember: it’s not just sweets—breakfast cereals, yoghurts, and even savoury foods may contain added sugar.
• Check labels for “free sugars” and aim to limit them.

Dental decay is preventable. By keeping sugary foods and drinks to mealtimes, brushing with fluoride toothpaste, and seeing the dentist regularly, you can dramatically reduce your child’s risk of tooth decay. Protecting baby teeth is just as important as protecting adult teeth—they help with eating, speaking, and holding space for permanent teeth.

A few small daily changes can make a big difference in keeping your child’s smile healthy for life.

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