Frequent consumption of sweets and inadequate cleaning of teeth creates ideal conditions for caries. Bacteria in plaque can then damage the teeth. This can be painful and lead to tooth loss. Nowadays caries is much rarer than it was a few decades ago.

At a glance

  • Caries develops through plaque bacteria, sweet foods and poor oral hygiene.
  • Caries damages the teeth, can be painful and cause tooth loss.
  • The initial indication of caries is whitish or brownish spots on the teeth.
  • In Germany, about eight out of ten twelve-year-olds do not have any caries.
  • Brushing teeth regularly with toothpaste containing fluoride and a diet that is low in sugar contribute to caries prevention.

Note: The information in this article cannot and should not replace a medical consultation and must not be used for self-diagnosis or treatment.

Caries: woman at the dentist’s opening her mouth. A doctor wearing surgical gloves and holding instruments is treating the teeth.

What is caries?

Caries is a tooth disease. The causes are plaque bacteria, sweet foods and poor oral hygiene. The disease damages the teeth, can be painful and eventually cause tooth loss.

Caries is also referred to as tooth decay. Nowadays the disease is much rarer than it was a few decades ago. The major reasons for this are that nowadays more people use toothpaste with fluoride and overall oral hygiene has also improved. This offers good options for keeping teeth healthy and preventing caries.

What are the symptoms of caries?

The initial indication of caries is whitish or brownish spots on the teeth. As the disease progresses, cavities develop on the tooth surface. If deeper tooth layers are attacked, the disease also damages the tooth nerves and roots. Caries makes the teeth sensitive and painful, especially when cold or sweet foods and beverages are consumed. Caries can damage teeth so severely that they have to be removed and replaced for instance by a bridge.

What are the causes of caries?

Causes of caries include poor oral hygiene, dental plaque, frequent consumption of sugar.

Caries normally develops when three factors come together: plaque, frequent sugar consumption and poor oral hygiene. Plaque covers the teeth like a film. It can feel furry and forms from bacteria, saliva and food residue. Bacteria on the tooth surface break down food residue and the sugar contained therein. In the process, acid is produced that attacks the tooth enamel. If the teeth are not cleaned or treated, they can gradually be destroyed by the acid. Caries bacteria can be transmitted through the saliva.

Children are especially vulnerable to caries because the tooth enamel in baby teeth is more sensitive than with permanent teeth. Caries jeopardizes the baby teeth when a child eats too much sweet food or consumes too many sugary drinks. In addition to that, it is not always easy to brush the teeth of babies or younger children. The risk for caries also increases when small children very often suck on a feeding bottle with sugared tea or juice.

Permanent teeth are also sensitive in the beginning. That is because when they come through, the tooth enamel is not yet fully hardened and therefore more susceptible to caries.

What causes caries?

The video below explains what causes caries, how it is treated and how it can be prevented.

This and other videos can also be found on YouTube

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How common is caries?

Many children and adolescents have healthy permanent teeth. In Germany, only about two out of ten twelve-year-olds are affected by caries – meaning that they have one or more diseased teeth.

Half of all children have already had caries by the time they reach 6-7 years of age. On average, people aged 35 – 44 have 11 teeth affected by it.

In the six to seven-year-olds with baby teeth, about half has had caries at least once.

Adults have caries more frequently. For those aged between 35 and 44, about eleven teeth on average are affected by caries, capped, have a filling or are missing.

How can caries be prevented?

Both children and adults can reduce their caries risk by brushing their teeth regularly with toothpaste containing fluoride. Fluoride is a substance that strengthens the tooth enamel and thus protects it from caries. Brushing moreover removes plaque containing bacteria and acids. It is recommended to brush the teeth at least twice a day after meals.

Dentists advise the use of toothpaste containing fluoride right from when the first baby tooth breaks through. However, pediatricians often recommend giving small children fluoride in tablet or drop form every day to start with. The teeth should then be brushed with just a small amount of fluoride-free toothpaste. But fluoride can have side effects, so children must not absorb too much of it.

Nutrition is also extremely important. Consuming fewer sugary foods means a lower risk of caries. Sweets and soft drinks for example contain a lot of sugar, as do fruit juices and ketchup.

Furthermore, regular dental check-ups are a good idea. They help with the early discovery and treatment of caries.

More detailed information about caries prevention can be found at

How is caries diagnosed?

Dentists usually detect caries already by closely examining the teeth. An X-ray can be taken in addition. This makes it possible to assess how far advanced the disease is, but also where exactly the caries is located – for instance between the teeth or under fillings.

How is caries treated?

Caries can be treated by fillings, root canal treatment; new techniques such as caries infiltration; toothpaste containing fluoride, dental prostheses, partial crowns or crowns.

Early caries can be recognized by white or brown spots on the teeth. In this early phase, regular brushing of the teeth with toothpaste containing fluoride can be sufficient. Those affected can moreover have fluoride applied to their teeth by their dentist.

If a cavity has already developed, it is drilled and treated with a filling. The filling can be made of plastic (composite), amalgam, ceramic or precious metal. Severely damaged teeth can be preserved with a partial crown or full crown. If the pulp is affected, a root canal treatment is usually suggested. Sometimes caries results in a tooth having to be removed. It can be replaced later by a bridge or dental implant with a fitted dental prosthesis.

Along with these caries treatment methods, there are various new procedures, some of which no longer require drilling. These include for instance so-called caries infiltration, which can be used for early caries. With this method, plastic is used to harden the tooth.

What else is important?

Many people go to their dentist not only because of acute symptoms, but also for regular check-ups. 

At you can find information on how to find the right dental practice and how you can best prepare for the visit. 

In cooperation with the Institute for Quality and Efficiency in Health Care (Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen) (IQWiG).

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