Preventing tooth decay in children and teenagers

Photo of a mother and child brushing their teeth (PantherMedia / lanak)

Tooth decay, also known as dental cavities or caries, is the most common dental problem in children. It can cause painful holes (cavities) in your teeth. Cavities usually need to be drilled and then filled to keep the tooth decay from getting worse. But doing certain things can help to prevent the need for treatment in the first place.

The most effective way to prevent tooth decay is by regularly brushing your teeth well and strengthening them with fluoride. It's also just as important to stick to a healthy diet and not have sugary foods or drinks too often. Last but not least, dental check-ups can help to detect and treat tooth decay early on. There's a lot of debate about whether fluoride tablets or fluoride toothpaste is better at preventing tooth decay in young children. Pediatricians tend to recommend using tablets, while most dentists recommend fluoride toothpaste.

What foods and drinks make a difference?

Tooth decay is mainly caused by bacteria in the plaque that coats your teeth, and by too much sugar in your diet. So limiting your consumption of sugary foods, drinks, candies and other sweets is one way to prevent tooth decay. Eating sweet things sometimes is perfectly fine, though, as long as you still take good care of your teeth.

The trouble starts when teeth are frequently exposed to sugary foods and drinks. Babies and toddlers may develop tooth decay faster if their bottle often contains sugary drinks or fruit juice. Unsweetened fruit teas or water are good alternatives. It's also important to use the bottle only for drinking and not as a pacifier or dummy.

One way to help strengthen your teeth more is by getting fluoride in your diet, for instance from salt containing added fluoride.

What should you know about brushing teeth?

Brushing your teeth gets rid of plaque and keeps your teeth looking and feeling clean. Fluoride toothpaste is especially good at helping to prevent tooth decay: Your teeth absorb the fluoride in the toothpaste, making them stronger.

Research has shown that brushing with fluoride toothpaste every day can help prevent tooth decay in children and teenagers. Children need adults to show them how to brush properly, and very young children need hands-on help. Even if a preschool child is already able to brush their teeth, an adult will usually need to help by touching up afterwards. If you're not sure how to go about it, you can get some practical advice from your dentist. Children generally start to brush their teeth properly on their own after they start school, around the time they can write well. It's important to brush the teeth thoroughly but also carefully, to avoid damaging the gums.


Once the first baby tooth comes in it's time to start brushing teeth. The following recommendations on the use of fluoride toothpaste apply to children who don't take any fluoride tablets. Children should only do one of these two things: either take fluoride tablets or use fluoride toothpaste. If you give your child fluoride tablets, then don't use fluoride toothpaste to brush their teeth.

Various doses of fluoride are recommended, depending on the child's age: Many dentists suggest using toothpaste that has 0.1% fluoride. This amount is often described on the package as “1,000 ppm” (parts per million). You can also use toothpaste with 500 ppm fluoride (0.05%) in toddlers, and you can then use a bit more of it to brush. The following is recommended for the use of children's toothpaste (twice daily):

Child's age Fluoride in the toothpaste Amount of toothpaste used
From the time the first baby tooth comes in until the child's second birthday 500 ppm Size of a pea
1,000 ppm Size of a grain of rice
Between the child's second and sixth birthdays 1,000 ppm Size of a pea

Older children and teenagers can brush their teeth like adults.

The reason why different doses are recommended is because of the possible side effects: Too much fluoride can cause white spots or stripes to form on the teeth as they develop. But it doesn’t usually have any other negative effects. In rare cases, too much fluoride can affect the development of the tooth enamel, increasing the risk of tooth decay. Whitish spots can also be an early sign of tooth decay.

It's especially important to get the fluoride dose right in young children because they often swallow their toothpaste. So it's advisable to not use additional fluoride tablets if they use fluoride toothpaste and if salt with added fluoride is also used at home.

Dental floss, interdental brushes and mouthwash

In order to prevent the gums from becoming inflamed (gingivitis), it may be a good idea to remove plaque that forms between your teeth by using dental floss, interdental brushes or toothpicks. These things haven’t been proven to prevent tooth decay, though. It’s important to be careful when removing plaque, because it’s easy to hurt your gums with floss, interdental brushes or toothpicks.

Mouthwash is another commonly used dental hygiene product. Some types of mouthwash contain fluoride. Regularly rinsing with fluoride mouthwash can prevent tooth decay too.

Interdental brushes, mouthwash and toothpicks are only options for older children and teenagers, though. Younger children can’t use them properly, and might swallow mouthwash.

Fluoride for toddlers: How should they use it?

Recommendations for preventing tooth decay in toddlers vary quite a bit in Germany:

  • Dentists recommend starting to brush their teeth with fluoride toothpaste from the time their first baby tooth comes in. If you use only the recommended amount of toothpaste when brushing, you don't have to worry if the child swallows some now and then.
  • Pediatricians say that it's better to give toddlers daily fluoride tablets or drops at first, and only brush their teeth with small amounts of fluoride-free toothpaste.

Fluoride tablets for toddlers contain a fixed amount of fluoride (0.25 mg). Pediatricians believe that fluoride tablets have an advantage over fluoride toothpaste for children because they make it easier to control the daily amount of fluoride. For the fluoride to be effective on the surface of the teeth, it's best to suck the tablets so they can dissolve slowly in the mouth.

As soon as children let you brush their teeth properly and can spit out the toothpaste, you can consider switching from tablets to fluoride toothpaste. This usually happens by the time children are between 2 and 4 years old.

How effective are fluoride varnishes and gels?

To prevent tooth decay, fluoride can also be applied directly to the teeth in the form of a varnish or gel. Fluoride gel is available from pharmacies without a prescription and can be put on at home. Most fluoride gels are applied once a week – it's best to check the package insert to see exactly how they are used and for which ages they are suitable. They should be left on the teeth for a few minutes and then spat out. Fluoride varnishes contain a higher concentration of fluoride. They are a applied by a dentist or dental assistant and harden immediately when they make contact with saliva. This is a particular advantage in toddlers because they don't have to spit out the varnish after a certain amount of time. Varnishes and gels can't replace regular tooth brushing or a tooth-friendly diet, though.

Research suggests that fluoride varnish can prevent tooth decay in baby teeth better than regular dental care (without any special use of fluoride) can. Permanent teeth can also benefit from the use of fluoride varnishes or gels.

In Germany, statutory health insurers cover the costs of fluoride varnishing

  • four times a year between the ages of 6 months and six years,
  • and twice a year between the ages of 6 years and 18 years (or four times a year if there's a greater risk of tooth decay).

Up to the age of 12 years, children can take part in group prevention programs at day care and in schools. This involves a dentist coming in about twice a year to check their teeth and mouth, see how their bite is developing and offer fluoride varnish to harden the dental enamel. Permission from the parents is needed before any fluoride is applied. This treatment is offered free of charge. But it may not be necessary if the child is already having regular fluoride varnish treatments at the dentist. The reverse is also true.

What is a dental sealant and when is it an option?

Children's back teeth (molars) are particularly prone to tooth decay. Bacteria can settle in the fissures, grooves and pits of these teeth. In children who have teeth that are prone to decay, the dentist can put a plastic sealant on the molars in order to stop bacteria from growing there. Applying the sealant doesn’t hurt, only takes a few minutes, and can lower the risk of tooth decay. Sealants usually last for several years. The dentist will check whether they are still intact during check-ups. In Germany, statutory health insurers cover the costs of this treatment on the permanent back teeth (molars) of children between the ages of 6 and 17 years.

How often should you go to the dentist for a check-up?

In Germany, children who are covered by statutory health insurance are eligible for dental check-ups from an early age. A total of six dental screening tests are offered between the ages of 6 months and 6 years. After that, it's still a good idea for the child to go in for a check-up every six months.

If any of the standard pediatric screening tests (U5, U6 or U7) show anything abnormal on the child's teeth or in their mouth, their dentist can take a closer look.

Some experts believe that regular dental check-ups can help to detect tooth problems earlier, leading to faster treatment. These check-ups also aim to help children and teenagers to take better care of their teeth and gums. But no studies have shown that having a check-up every six months is better for your overall dental health.