Tooth decay

Cavities are a very common infectious disease that gradually destroys the components of the tooth, starting with the hard tissues (enamel and dentin) and progressing to the dental pulp, which contains the nerves. It can also develop on the root of the teeth if it is exposed. Dental caries is the result of the attack of the tooth by acids produced by the microorganisms of plaque (biofilm) accumulated on the teeth.

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The main cause of the appearance of cavities is the presence of dental plaque (biofilm).

Despite regular tooth brushing, certain habits can promote the presence of plaque:

  • Absorption of sweetened liquid: if the sugar in liquids such as soft drinks or milk (lactose), for example, remains in the mouth too long, it is metabolized by plaque bacteria (biofilm) to produce acid;
  • Snacking between meals: despite effective tooth brushing immediately after meals, the carious process can remain active if food is introduced into the mouth after meals;
  • Poor tooth alignment makes daily tooth maintenance difficult and promotes the accumulation of food debris and plaque (biofilm) between teeth;
  • The presence of cracks (e. g. broken teeth) reduces the protective power of the enamel;
  • Defective fillings or large quantities of fillings can allow decay to infiltrate;
  • The absence or lack of saliva flow;
  • Inadequate hygiene habits;
  • Inadequate maintenance of prosthetic appliances including partials, bridges and fixed or removable orthodontic appliances;
  • Smoking and/or frequent use of cannabis;
  • Certain medical conditions requiring, for example, chemotherapy;
  • Irregular or excessively spaced dental examinations.

Emergency advice

Make an appointment with the dentist as soon as possible. In the meantime, here are some recommendations:

  • Avoid sugary drinks and foods;
  • Brush your teeth regularly, floss and use a mouthwash enriched with fluoride.


  • Amalgam restoration;
  • Composite restoration.

Stages of problem evolution

Stage 1 of caries

In the initial stage, the acid causes decalcification and decomposition of the different structures of the tooth by demineralizing it, starting with the enamel. No pain is yet felt.

Stage 2 of caries

If the cavity is not stopped, it will progress and destroy the dentin of the tooth under the enamel. At this stage, careful and thorough brushing and flossing of the teeth will not prevent it from developing, as the bristles of the brush can only access the surface of the infected site.

Stage 3 of caries

The survival of the tooth is severely compromised when the cavity reaches the pulp, causing pain and allowing the infection to spread. At this stage, root canal treatment is almost the only way to preserve the tooth. This is possible if the remaining walls of the decayed tooth are not too damaged and are in sufficient quantity.

Stage 4 of caries

In addition to compromising the vitality of the tooth, the infection that has invaded the entire dental pulp can spread and form an abscess at the root tips. The pus cluster located in the abscess causes bone destruction that contains the infection and destruction can progress to piercing the jaw bone causing a fistula allowing pus to flow out.

Without the elimination of pus, symptoms such as swelling, fever and acute pain will appear. If the tooth is too heavily affected by cavities, the tooth may have to be extracted.

Possible complications

  • Nerve and alveolar bone damage;
  • Abscess;
  • Need to extract the infected tooth;
  • Sepsis (discharge of bacteria into the blood);
  • Sinus infection if the abscess is in the upper molars.

Prevention tips


  • The absorption of sweet liquid;
  • Snacking between meals.

The most recommended methods to prevent cavities and maintain good oral health remain:

At home

  • Brushing your teeth two to three times a day using a good technique;
  • Flossing.

In the dental office

  • A dental examination and cleaning once or twice a year at the dentist;
  • The sealing of the permanent molars as soon as they erupt;
  • The analysis of the salivary Ph in order to know the propensity to dental caries;
  • Diet analysis to identify foods with cariogenic potential.