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What is tooth decay?

Tooth decay is a diet-related disease that damages teeth.

Tooth decay happens when bacteria in the mouth create a sticky covering called plaque on the tooth surface. These bacteria feed on sugars in food and drinks and produce an acid that damages the tooth surface. Over time, this acid eats away at the surface of the tooth, creating holes or ‘cavities’.

Tooth decay can cause pain and infection. It can even affect children’s growth. Severe tooth decay can have serious consequences for your child’s nutrition and their speech, jaw and teeth development.

If tooth decay is spotted early, it can be treated. If tooth decay is left untreated, your child might experience:

  • pain and discomfort
  • a higher risk of new decay in baby and adult teeth
  • more complicated and expensive treatment, including loss or removal of teeth
  • anxiety when they visit a dentist
  • loss of time at school.

Tooth decay is also called dental caries.

Signs of tooth decay in babies, children and teenagers

Early tooth decay can be hard to spot. The first sign of tooth decay is when teeth develop a dull, white band along the gum line (the area at the base of the teeth, near the gums). You might also see brown spots on the teeth, and the gums might be red or purple and swollen.

With more advanced tooth decay, you might notice blackened holes in the teeth or broken teeth. If the decay has led to an infection, you might notice lumps or pimples on the gums or swelling around the gums and face.

Tooth decay prevention: key steps

There are 3 key steps your child can take to prevent tooth decay:

  • Brush their teeth and gums twice a day – in the morning and at night.
  • Eat a healthy, low-sugar diet, and develop healthy eating habits.
  • Have regular check-ups with the dentist.

How to prevent tooth decay: brushing teeth and dental care

Cleaning and caring for children’s teeth early on sets up good dental habits for life. The following articles have information about cleaning, brushing, toothpaste, toothbrushes and dental floss for children of different ages:

  • Dental care for newborns
  • Dental care for babies
  • Dental care for toddlers
  • Dental care for preschoolers
  • Dental care for school-age children
  • Dental care for pre-teens
  • Dental care for teenagers

How to prevent tooth decay: healthy foods and drinks

Food and drinks affect your child’s dental health and the development of tooth decay.

Babies under 6 months

Newborns and young babies need only breastmilk or formula until you introduce solids at 4-6 months. If your baby likes a dummy, don’t dip it in food, sugar or liquids like honey.

Babies over 6 months

When your breastfed or formula-fed baby is older than 6 months, they can also have small amounts of water. Avoid giving your baby sweetened milk, fruit juice or cordials. If your baby likes a dummy, don’t dip it in food or liquids like honey and sugar.

Older babies, children and teenagers

Children need a wide variety of healthy foods and snacks. Foods and drinks that are low in sugar are best. Avoid giving your children sweet biscuits or cakes. If your child does eat something sweet, drinking a glass of water or eating tooth-friendly food afterwards can reduce the amount of acid on your child’s teeth.

Tooth-friendly foods have low sugar, promote chewing and get your child’s saliva going. Cheese and chopped vegetables like carrot and celery are examples of tooth-friendly foods.

How to prevent tooth decay: healthy eating habits

Healthy eating habits can also prevent tooth decay. This means being careful about when and how your child eats.

For example, the longer food and drink stays in your child’s mouth, the more chance there is for acid to develop and damage the surfaces of your child’s teeth. So grazing on foods and sipping drinks over long periods of time is more likely to cause tooth decay.

These tips can help you discourage your child from long periods of eating or drinking:

  • Set regular times for snacks and meals, rather than letting your child ‘graze’ all day.
  • Aim to leave 1½-2 hours between meals and snacks, including sweet drinks.
  • Make sure your child eats and drinks in one place only – for example, at the table.
  • Put food away when snack time or mealtime is over.
  • Encourage your child to drink tap water if they’re thirsty, rather than juice, cordial or soft drink.

How to prevent tooth decay: regular dental check-ups

Regular dental check-ups can help your child avoid tooth decay. Your dentist will tell you how often your child needs a check-up. Dentists usually recommend every 6-12 months.

If you think your child has tooth decay, it’s important to visit a dentist to stop the decay or infection from getting worse.

If your child has signs of being generally unwell, like a fever or facial swelling, and you think these might be because of dental problems, see your dentist or GP or go to a hospital emergency department straight away.

Other ways to help children and teenagers avoid tooth decay

Being a role model

You can set a good dental health example for your child by:

  • brushing your own teeth twice a day
  • using waxed floss to clean between teeth once a day
  • limiting your sugar intake
  • being positive about going for dental check-ups.

Bottle-feeding and breastfeeding

It’s recommended that you don’t settle your baby in bed with a bottle of breastmilk or formula. Settling babies to sleep with bottles can lead to tooth decay. This is because the lactose in milk promotes growth of the bacteria that cause tooth decay. And when your baby is asleep, there’s less saliva in their mouth to protect their teeth from this.

Asthma inhalers

These are a vital part of some asthma action plans, but the powder in some inhalers is acidic and can damage tooth enamel. This could lead to tooth decay over time if it isn’t balanced with good dental hygiene.

To avoid tooth decay, rinse your child’s mouth with water immediately after each use of the inhaler. Ensure that your child’s teeth are cleaned twice a day with fluoride toothpaste. But don’t brush teeth straight after using the inhaler – allow 30-60 minutes before brushing.

Medicines

Some medicines can affect your child’s dental health because of their sugar content. Check the labels of medicines for any hidden sugars, particularly if your child will be taking the medicine for a long time. Always ask for sugar-free medicine from your pharmacist.

Some medicines can reduce saliva production, which can lead to tooth decay and other dental health problems. Talk to your doctor or pharmacist about the effects of medicines on saliva and teeth. Older children and teenagers could try chewing sugar-free gum if they’re using these medicines. It stimulates saliva flow and helps to protect teeth from decay.

You can also encourage your child to rinse their mouth with water immediately after taking medicine and brush with fluoride toothpaste 30-60 minutes later.

Sports drinks

The acidity and sugar in sports drinks can cause decay and damage your child’s teeth, particularly if your child drinks them regularly. This can lead to permanent damage to your child’s teeth and further dental treatment.

It’s best for your child to avoid sports drinks and drink plenty of water instead. When your child does drink sports drinks, it’s good for your child to rinse with water straight away and brush their teeth with a fluoride toothpaste 30-60 minutes later.

Food and drinks aren’t the only things that can erode the surfaces of your child’s teeth. Vomiting or gastric reflux can also have a nasty effect. If your child has been vomiting, they can protect their teeth by rinsing straight away with water and brushing their teeth 30-60 minutes later.

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Raising Children Network is supported by the Australian Government. Member organisations are the Parenting Research Centre and the Murdoch Childrens Research Institute with The Royal Children’s Hospital Centre for Community Child Health.

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  • The Royal Children's Hospital Melbourne
  • Murdoch Children's Research Institute

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