Tooth decay & caries: symptoms, treatments and prevention

What is tooth decay and how is it caused?

Dental caries, also known as tooth decay, is one of the most prevalent oral diseases in the world. The WHO (World Health Organisation) emphasises the importance of oral health and, they actually say that, 'untreated dental caries in permanent teeth is the most common health condition according to the Global Burden of Disease 2021.'

A large percentage of oral health issues and caries could be avoided with better treatment and prevention packages within universal healthcare. There is a significant correlation between poor oral hygiene, plaque buildup, and the incredibly high demand for tooth decay treatment.

Whether you're looking for information on how to avoid cavities, or you want to understand exactly what they are, we'll give you an answer to all your questions right here!

What is a cavity?

Most dentists use the term 'cavities' to describe the presence of tooth decay or caries. Technically speaking, the cavity is the hole produced by caries. Cavities and caries can also develop from chipping your tooth, or having a broken tooth which causes a cavity and invites infection and decay.

What is a dental carie?

Dental caries are a more technical term and refers more specifically to the bacterial disease that starts the decay. It occurs as a result of the bacteria in your mouth that feeds on sugar from the foods you eat.

How is tooth decay caused?

The fewer rich vitamins and minerals you eat in your diet, and the more starchy, carby and sugary foods and drinks you consume, the more likely you are to face cavities and root extractions. Decay can sometimes be caused by medications too.

Caries and 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 demineralisation of the tooth's enamel surface. This occurs because plaque, bacteria that excretes acid, demineralises the enamel surface.

You might notice white spots appearing on your teeth at this point, which is an indicator of the start of tooth decay. When the enamel surface is demineralised, the plaque reaches the more porous surface of the dentin.

A fertile ground for cavities

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

1. Some people have weaker teeth with fine, poorly mineralised 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.
2. The pH of saliva can differ depending on each person and their diet. People with an acidic pH higher than average are more prone to develop cavities.
3. On the other hand, patients who are immunosuppressed by medication also have a higher likelihood of developing dental caries. Their defences are lower, and it is easier for cavities to appear.

Other reasons for tooth decay

• Living in communities with no fluoridated water supplies

• Diets rich in sugars, refined carbohydrates and sweets

• Poor oral hygiene

• Reduced flow of saliva, or dry mouth

• Low pH saliva that produces acid

• Being an older adult

How to prevent tooth decay

• Opt for fluoride-based toothpastes

• Foods rich in fluorides: seafood, shrimp, crab and nuts, such as almonds and walnuts

• Visit the dentist regularly

• Take the time to brush your teeth for long enough

• Don't brush too harshly as it can remove enamel

• Include the use of dental floss in your daily regimen

Excessive consumption of sugar is one of the biggest contributors to the deterioration of teeth and decay, along with poor hygiene. Too many sugary treats during the day, gives little time for the saliva to neutralise the sugars. This means the bacteria in the plaque will convert these sugars into acid, causing what is known as tooth decay.

Preventing caries in children

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, to maintain good oral hygiene and keep teeth clean.

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. If identified in the early stages, it is reversible.

For that reason, we always recommend booking an appointment with your dentist to confirm if this is the case:

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. If left untreated, tooth removal may be necessary.

Consequences of dental caries

• 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 and cavities 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 infection affects all, not just part of the tooth. As a result, it may suffer necrosis and the patient may lose it.

• Radiating pain in the jaw and ear is also a consequence of caries.

Visit your dentist regularly

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 function.

If the dentist detects that the caries needs to be treated with a tooth filling, they will notify the patient and let them know that this procedure will require the use of infiltrative anaesthesia 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. Once removed, the remaining surface is decontaminated.
2. An adhesive technique is used to glue the filling material. 
3. The seal is inserted. This returns the lost dental anatomy.
4. 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. 
5. The composites are of different colours, and the professional selects the appropriate colour for the patient's dentition so that it is as noticeable as little as possible.

Crowns

When the tooth cavity treatment requires a more serious approach and a filling cannot be used, 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, or tooth extraction. Edentulism, is the medical term for tooth loss, and it 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. 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.

Having fixed orthodontics in place can make maintaining your oral hygiene more difficult, which is one of the reasons removable orthodontics are a great solution. With the use of removable orthodontics, such as invisible aligners, this difficulty disappears. The aligners can be removed, allowing you to maintain an adequate brushing regime.

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 to use impress clear aligners.

During your first visit to Impress, a panoramic X-ray and oral exam are performed. These free evaluations, help us detect other possible problems, such as identifying cavities and advising you so you can act accordingly before starting any treatment.

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're ready to start your teeth straightening journey and could benefit from a free orthodontic evaluation, find your nearest Impress clinic. You can also contact us by making an appointment through our website, by phone or WhatsApp at +44 20 3808 1072.

Updated: May 2025

Sources: https://www.who.int/news-room/fact-sheets/detail/oral-health