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 amongst 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 and strengthening them with fluoride. Sticking to a healthy diet and not eating too much candy or sweets is also good for your teeth. Last but not least, dental check-ups can help detect and treat tooth decay early on.

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 gum is one way to prevent tooth decay. Eating sweet things every once in a while is perfectly fine, though, as long as you still take good care of your teeth.

The trouble starts when teeth are in constant contact with sugary foods and drinks. Toddlers may develop tooth decay faster if their bottle usually contains sugary drinks or fruit juice. Unsweetened teas or water are good alternatives.

One way to help strengthen your teeth is by getting fluoride in your diet, for instance from salt containing added fluoride. Some other foods also have added fluoride in them, and many types of mineral water contain fluoride. Tap water in Germany contains relatively little fluoride.

What do you need to keep in mind when brushing your 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.

It has been shown that children and teenagers can prevent tooth decay by brushing with fluoride toothpaste on a daily basis. Children need adults to show them how to brush properly, and very young children need hands-on help. Even if a preschool child is able to brush their teeth, an adult may need to help by touching up afterwards. It is important to brush the teeth thoroughly but also carefully, to avoid damaging the gums.


Fluoride toothpaste can strengthen the teeth most effectively and offer the best protection from tooth decay. Different types of toothpaste are recommended for children of different ages: Toothpaste with an especially low dose is available for younger children. It has about 0.05% fluoride in it. This amount is often listed on the package as “500 ppm” (parts per million). Toothpaste that has over 0.1% fluoride in it (more than 1000 ppm) is only recommended once permanent teeth have come in – usually when the child is about six years old.

These different doses are recommended to take possible side effects into account: Getting too much fluoride can leave white spots or streaks on your teeth, but doesn’t usually have any other negative effects. In rare cases, too much fluoride can damage the enamel, increasing the risk of tooth decay. Some people worry that fluoride could lead to loss of bone mass or kidney damage, but this only happens if extremely high doses are taken on a daily basis.

It is especially important to get the fluoride dose right for young children because they often swallow their toothpaste. If they are also taking fluoride tablets and eating food with fluoridated salt, they may easily get too much fluoride. Toothpaste also contains ingredients that shouldn’t be ingested in larger amounts. That’s why it’s important to teach children early on to spit out toothpaste. If they aren’t yet able to do so, it‘s better to brush their teeth with very small amounts of toothpaste. Non-fluoride toothpaste may be better suited for children who take fluoride tablets.

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 mouthwashes contain fluoride. Regularly rinsing with fluoride mouthwash can effectively prevent tooth decay too.

Floss, interdental brushes and mouthwash are only options for older children and teenagers, though. Younger children can’t use them properly, and may swallow mouthwash.

Fluoride for younger children: How should they take it?

Recommendations for preventing tooth decay in toddlers vary quite a bit in Germany. Dentists recommend starting to brush their teeth with fluoride toothpaste early on. Pediatricians often say that it is better to give toddlers fluoride tablets at first, and brush their teeth with small amounts of non-fluoride toothpaste.

Fluoride tablets contain a fixed amount of fluoride (0.25 mg). For the fluoride to be effective, the tablets are meant to dissolve slowly in the mouth. Research has shown that regularly taking fluoride tablets lowers children’s risk of tooth decay. This is especially true if the tap water contains hardly any fluoride, as is the case in Germany, for example. The advantage that tablets have over toothpaste in toddlers is that the daily dose of fluoride can be better regulated. It's also not clear whether children’s toothpaste with low levels of fluoride in it (less than 0.05% or 500 ppm) even prevents tooth decay at all.

It’s often quite difficult to brush young children’s teeth well enough – and they are also likely to swallow some of the toothpaste. So there are a few good reasons to give them fluoride tablets and brush their teeth with fluoride-free toothpaste to start off with. As soon as they are able to brush their teeth properly and spit out the toothpaste, you can switch 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?

Dentists can apply fluoride varnish or gel to teeth. This can offer protection from tooth decay for several months at a time. But it can’t replace regular tooth brushing or a tooth-friendly diet. Children and teenagers who brush their teeth properly anyway probably won’t get much extra protection from using gels or varnishes. The benefit is greater in people with poor oral hygiene or early stages of tooth decay.

In Germany, statutory health insurers cover the costs of this treatment twice a year in children between the ages of 6 and 17. Fluoride gel is also available from pharmacies without a prescription and can be put on once a week.

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

The back teeth (molars) are particularly prone to tooth decay. Bacteria can settle in the fissures, grooves and pits in these teeth. The dentist can put a sealant on the larger back teeth if children have teeth that are likely to have problems or already have deeper grooves, to keep 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 can check whether they are still intact during check-ups. In Germany, statutory health insurers will cover the costs of this treatment on the permanent back teeth (molars) of children between the ages of 6 and 17.

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

Twice a year, once a year or less often? The question of how often you need to have check-ups has been the subject of international debate for over 30 years. Seeing the dentist every six months is probably the most common recommendation. In some countries, people who have healthy teeth and intact gums are advised to go only once a year or every two years. In people who have dental problems, though, more regular check-ups are recommended.

Having regular dental check-ups may generally make it possible to treat any problems with your teeth sooner. Another potential advantage is that check-ups may help encourage some people to look after their teeth and gums better. But no studies have shown that having a check-up every six months is better for your overall dental health. People who are very careful about cleaning their teeth and gums are probably less likely to benefit from regular check-ups than people who pay less attention to their dental hygiene. It might be best to talk with your dentist about how often you need a check-up.