Tooth decay & caries: symptoms, treatments and prevention

30 December · 5 minutes

Dental caries, also known as tooth decay, is one of the most common oral diseases in the world. The WHO (World Health Organization) emphasizes the importance of oral health and, in particular, the relevance of tooth decay treatment to avoid health complications.

But what are dental caries? How can we know if we have any? And when and how should we treat them? Read on below, we tell you everything you need to know.

Tooth decay and cavities: what are they and how do they appear?

Before getting started, it is important to know what a tooth cavity is. Cavities are the result of the progressive deterioration of enamel and dentin by plaque germs.

As for how tooth decay begins, it all starts with the demineralization of the tooth's enamel surface. This occurs because plaque, bacteria that excretes acid, demineralizes the enamel surface. When the enamel surface is demineralized, the plaque reaches the more porous surface of the dentin.

If the caries reach the dentin, we are already talking about an internal or advanced stage of dental caries. These are deeper, harder to stop, and can cause pain.

What causes tooth decay?

A fertile ground for cavities

What causes cavities is a difficult question as the origin is not the same in all patients.

  • Some people have weaker teeth with fine, poorly mineralized enamel, which can be a genetic issue. In these cases, the teeth are more sensitive to plaque acids and therefore are more likely to suffer from cavities.
  • The pH of saliva can also be different depending on the person and their diet. Those with an acidic pH higher than average are more prone to develop cavities.
  • On the other hand, patients who are immunosuppressed by medication also have a higher likelihood of developing dental caries. Their defenses are lower and it is easier for cavities to appear.

A woman waiting for treatment about her tooth cavity

An unhealthy diet as a cause of tooth decay

People who frequently eat foods that are too acidic or very sugary are more at risk of tooth decay. Sugar and tooth decay are very closely aligned.

Excessive consumption of sugar is one of the main causes of tooth decay along with poor hygiene. If we have too many sugary treats during the day, we do not give time for the saliva to neutralize the sugars. This means the bacteria in the plaque will convert these sugars into acid, causing what is known as tooth decay.

In addition to reducing sugar intake, it is also important to control the quantity and improve the quality, that is, to avoid consuming sugar in sticky forms since sugar in this form adheres to the tooth surface and is more difficult to remove.

Poor dental hygiene

Since dental plaque is the root cause of dental cavities, poor oral hygiene is directly linked to it. Another factor that favors the appearance of dental cavities is not brushing your teeth or doing it incorrectly.

We recommend having a good brushing technique and to do so regularly. The use of dental floss is also important, since it allows access to areas that the toothbrush has difficulty reaching.

Signs and symptoms of tooth decay

Tooth decay symptoms can vary depending on the severity of the cavities and where they are located. If you experience any of the following symptoms it is possible that you have tooth decay, although to confirm this you should consult your dentist:

  • Cavity symptoms include pain or sensitivity when you expose the affected tooth to cold, heat or sweet foods. This is normally the first sign you may have a cavity.
  • Spots on the teeth that can be white (in the initial phase, also called white or mild cavities) or black (more advanced).
  •  Sometimes they can be seen with the eye (a hole can be noticed in the tooth) but, sometimes, cavities appear between the teeth so they cannot be detected so easily.
  • Severe tooth cavity symptoms may include pain, throbbing and stinging. 

A woman holing her cheek in pain

Is it possible to know the different stages of a cavity?

It is possible to know approximately the stage of tooth decay and caries based on the patient’s symptoms:

  • If a stimulus occurs and the discomfort is spontaneous (lasts less than a minute), it is possible that it is a reversible cavity.
  • If the discomfort lasts more than a minute, it is an indication that the cavity is already developed.
  •  If the discomfort persists, without stimulation, it may mean that the cavity is at an advanced stage. Those symptoms can be an indicator that the caries have already reached the nerve and an X-ray is required.

Consequences of dental caries

Whenever you experience any of the symptoms mentioned above, you must consult your dentist to treat the problem as soon as possible. Otherwise, the consequences of not treating a cavity can be varied and can include:

  • If it is not treated when it is still a white cavity (without reaching the dentin), a filling could fix the problem. When non-natural filling materials are used, a more frequent review period is necessary and these materials may change from time to time (depending on the patient’s oral hygiene).
  • Dental cavities trap more plaque and can cause more cavities to appear.
  • One of the most frequent consequences of tooth decay is a greater sensitivity to heat, cold and sugary or acidic foods.
  • Tooth decay can also cause bad breath.
  •  If the caries reaches the nerve, it may be necessary to perform a root canal treatment, also called endodontics.
  • With advanced dental caries, the tooth may suffer necrosis and the patient may lose it.
  • In addition, radiating pain in the jaw and ear are also consequences of caries. 
 A dentist performing a treatment

Effects of tooth decay on the body

Apart from the consequences of tooth decay mentioned above, cavities that have been neglected for too long can lead to other complications that can affect other parts of the body.

For example, if tooth decay attacks the root of the pulp, penetrating it and reaching nearby tissues, the resulting infection can be very painful, they can expand, and even cause abscesses (accumulation of pus).

In addition, in the most extreme cases, if the cavity is in the lower jaw and the infection becomes complicated, it can cross the floor of the mouth and reach other parts of the body through the blood vessels, and can even lead to endocarditis. (inflammation of the heart chambers and valves).

How to prevent tooth decay and cavities?

Choose products with fluoride

Fluoride reduces bacteria that causes cavities and strengthens teeth so it is added to some dental products. Therefore, as a measure to prevent cavities, toothpastes and mouthwashes containing fluoride are a good option.

Ensure good oral hygiene

Preventing cavities begins with adopting good hygiene habits. Like all habits, oral hygiene must be instilled from an early age as cavities can even appear in baby teeth.

Parents are advised to check their children's teeth regularly and to remain vigilant during adolescence as brushing is often forgotten. It is recommended to brush your teeth at least twice a day for 2 minutes. Ideally, brush your teeth after every meal.

A mother and daughter brushing their teeth

Adopt a healthy diet

As mentioned above, in terms of diet, sugar is our teeth's greatest enemy.

So be careful with sodas and juices that contain added sugars, pastries, gummies and other sweet foods.

Visit your dentist regularly

 Finally, as a measure to prevent and avoid cavities, it is recommended that you visit the dentist at least once a year. During this visit you should request an oral exam and hygiene appointment. However, depending on the condition of your teeth, your dentist may suggest more frequent follow-ups.

Tooth decay treatments: How to get rid of cavities?

Tooth decay treatment will depend on the state of the cavities themselves. White cavities (milder cavities) can simply be treated with fluoride. In the case of more advanced cavities, the treatments can be varied. These are the most common.

Tooth cavity filling

To begin with, it is important to explain what a dental filling is. Filling consists of filling a tooth that has been damaged by a cavity in order to restore its shape and functions.

If the dentist detects that the caries must be treated with a tooth filling, they will notify the patient and let them know that this procedure will require the use of infiltrative anesthesia in the area to be treated. During this process the following steps are carried out:

  1. The professional uses an instrument that can be rotary or manual to remove the damaged tissue.
  2. Once removed, the remaining surface is decontaminated.
  3. An adhesive technique is used to glue the filling.
  4. The seal is inserted. This returns the lost dental anatomy. The filling contains composite resins (composites) that have a chemical bond with the tooth and present a ceramic load to be able to return the part to its mechanical functions. The composites are of different colors and the professional selects the appropriate color for the patient's dentition so that it is noticeable as little as possible.


When the tooth cavity treatment requires a more serious approach and a filling cannot be made, the dentist must replace the natural crown of the tooth with a kind of cover after removing all the decayed part.

Canal treatment

When the nerve is affected and the pulp cannot be recovered, the canal is treated. This is called root canal treatment. This treatment for cavities is the last resort.

Caries and orthodontics

Can braces cause tooth decay?

While some people could think that braces can cause tooth decay, orthodontic devices are not linked to the development of cavities. However, cavities tend to develop mostly in the back teeth (in the molars) and these teeth are the most difficult to reach with a toothbrush and floss, which can be even more difficult with the use of fixed orthodontics. With the use of removable orthodontics, such as Impress’ invisible aligners, this difficulty disappears. The aligners can be removed, allowing a better brushing technique.

However, with the use of any type of orthodontics we must pay special attention to the accumulation of plaque. To avoid the development of new cavities, it is very important to maintain a good dental hygiene routine, whatever the orthodontic treatment.

A set of invisible aligners

Can you get braces or aligners if you have cavities?

Our priority is the dental health of our patients, so if the patient has any cavities that have not been treated previously, our recommendation will always be to treat the cavities before starting treatment. In this way, we prevent cavities from continuing to advance during orthodontic treatment, causing more serious problems.

During the first visit to Impress, a panoramic X-ray and oral exam are performed. These procedures, in addition to helping us detect other possible problems, help us to locate cavities and act accordingly. Caries filling is one of the most common pre-treatments and, to facilitate the start of treatment with aligners, in some of our clinics we have qualified experts to perform this type of intervention.

If you are thinking of improving your smile, get in touch with us and find out about our orthodontic treatments and pre-treatments available at your nearest Impress clinic. You can contact us by making an appointment through our website, by phone or WhatsApp at +44 20 3808 1072.

Find out without obligation about our prices, orthodontic treatments and pre-treatment. We look forward to hearing from you!

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FAQs about dental caries

How to ease tooth cavity pain?

If your cavity pain is becoming more noticeable, it means that it is in a relatively advanced state. In this case, it is best to make an appointment as soon as possible with your dentist in order to solve it.

Can tooth decay be reversed?

You can reverse tooth decay as long as it is in an initial stage, that is, when there was plaque present but it caused little demineralization (it did not completely perforate the enamel surface). In this case, it can be reversed with hygiene and application of fluoride.

Can tooth decay spread?

The main bacteria that cause cavities is Streptococcus Mutans and it is transmitted between humans, so we must be careful with seemingly harmless practices such as sharing a glass or cutlery.

How long can you leave a cavity untreated?

Cavities should not be left untreated as they can lead to more serious problems. If you have any symptoms, see your dentist.

Does tooth decay cause bad breath?

Yes, one of the consequences of cavities is bad breath.


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