Tooth decay stages: From cavity to serious complications

Tooth decay is a very common problem that has been around for a long time, especially because we now consume more sugary foods.

When we eat sugars, bacteria in our mouths break them down and create acid. This acid can harm our teeth by dissolving their minerals, leading to cavities over time.

We will discuss in this article the different stages of tooth decay and the treatment options available.

How does tooth decay occur and progress over time?

Did you know that?

The enamel that covers the tooth is the hardest tissue in our body. It contains the highest percentage of minerals (at 96%).

To understand how tooth decay progresses, let's take a closer look at the structure of our teeth.

Enamel Rods

Enamel, the outermost layer, is made up of tiny crystals called enamel rods. These rods are tightly packed together, giving the enamel its strength and rigidity.

However, despite being the hardest tissue in our bodies, enamel has a weakness.

Tooth decay progress: From demineralization to cavity

When our mouths become acidic, the chemical bonds holding the enamel's hydroxyapatite crystals together start to break down. This process creates small lesions or weak spots on the tooth surface, known as surface demineralization.

At this early stage, tooth decay can be stopped or even reversed with proper care and oral hygiene.

However, if the demineralization is left untreated, it can progress further into the enamel, forming an irreversible cavity.

At some point, decay moves beyond the enamel and reaches the layer beneath, known as dentin. Dentin is also a mineralized tissue, but it is less dense than enamel, making it more vulnerable to rapid destruction.

Once decay has reached the dentin, there's no alternative but to remove the decayed tissue and restore the tooth with a filling material.

At a more advanced stage, decay continues to progress towards the innermost layer, called the pulp.

The pulp is a soft tissue that contains nerves and blood vessels. When the pulp is affected, it can cause irreversible inflammation and intense pain. In such cases, a root canal treatment becomes necessary to remove the infected pulp and save the tooth.

Tooth decay stages:

Tooth decay is a gradual process that goes through several stages.

1. Enamel stage

superficial stage

At this stage, decay first affects the outermost layer of the tooth, called the enamel. In this superficial stage, you may not feel any pain, making the lesion challenging to detect. However, you might notice whitish or brownish spots on your teeth, indicating surface demineralization.

The good news is that at this early stage, decay can be stopped or even reversed. This is because enamel can respond well to remineralization treatments. However, left untreated, demineralization can progress and evolve into a cavity.

Treating the enamel stage:

When decay is limited to the enamel surface, remineralization treatments can be effective. These aim to strengthen and repair the weakened enamel by replenishing essential minerals.

These treatments involve regular applications of fluoride or other phosphorus-calcium-based products to fill in the damaged porous areas.

Your dentists may recommend fluoride supplements (mouthwash, dental gel, or highly concentrated toothpaste) or dental sealants to promote remineralization and prevent further decay.

You should also ensure that you practice good oral hygiene and adapt your diet to provide an optimal environment for your teeth to heal.

2. Dentin stage

When decay progresses beyond the enamel, it reaches the dentin, which is in direct contact with the pulp. At this stage, you may experience sensitivity to cold and pressure.

Dentin decay is deeper and more severe than enamel decay, making it inaccessible to topical remineralization treatments. It also tends to progress rapidly ad dentin is less resistant.

The treatment at this stage involves removing the decayed tissue and replacing it with a filling to protect the underlying pulp.

dentin stage

Treating the dentin stage:

When tooth decay progresses to the dentin, more extensive treatment becomes necessary. The primary approach for treating dentin decay involves the removal of the decayed tissues and restoring the tooth with a filling.

The choice of filling material depends on the extent of decay and the specific tooth involved.

In cases where the damage is not extensive, a composite filling (tooth-colored) or amalgam filling (silver-colored) is often sufficient to restore the tooth's functionality. These can be achieved in a single visit to the dentist's office.

However, if the tooth is significantly weakened or has a larger cavity, a two-visit restoration may be the recommended option. This can include procedures such as inlays, onlays, or dental crowns.

3. Pulp stage


The pulp is a vital tissue located in the center of the tooth, containing nerves and blood vessels.

When decay reaches the pulp, it causes inflammation, resulting in a condition called pulpitis.

You will experience severe pain due to increased pressure within the tooth.

If the infection persists, the blood vessels supplying the tooth can become severed, leading to pulp death or necrosis. The tooth then becomes insensitive.

Treating the pulp stage:

Once decay reaches the pulp, root canal treatment becomes necessary.

During the procedure, the infected pulp is completely removed from the tooth. The root canals are then cleaned, disinfected, and filled with a special material to prevent further infection.

After the root canal, depending on what remains of the tooth, the treatment options may be as follows:

  • Regular filling.
  • Dental crown.
  • Endocrown.
  • Post and core crown.

4. Complications

In the final stages of tooth decay, various complications can arise. When the pulp dies, the infection can spread beyond the tooth, leading to dental abscess, cellulitis, sinusitis, sepsis, and endocarditis.

Final stage of tooth decay: Periapical Periodontitis

  • Dental abscess: It forms beneath the root tip and cause swelling, redness, and localized pain that can spread to the surrounding jaw area.

  • Cellulitis: In advanced stages, the infection can spread to the external tissues of the face and neck, resulting in swelling, redness, and a sensation of heat. Prompt treatment is crucial, as the infection can spread to life-threatening areas.

  • Sinusitis: The roots of the upper molars are close to the maxillary sinuses. A dental infection can reach these bony cavities, leading to sinusitis.

  • Endocarditis: Bacteria from a dental abscess can enter the bloodstream and reach the heart, causing bacterial endocarditis.

  • Septicemia: Bacteria involved in pulpitis can enter the bloodstream and affect other organs, including the kidneys, lungs, and liver. Individuals with pre-existing organ-related diseases are at higher risk.

How to prevent tooth decay in the future?

Some tips to prevent cavities include:
  • Brush with a fluoride toothpaste at least twice a day.
  • Floss your teeth daily.
  • Visit your dentist regularly.
  • Drink a lot of water.
  • Balance your diet.
  • Avoid snacking and sipping frequently.
  • Eat healthy foods for your teeth that are rich in minerals and water like green vegetables, cheese, apples, tea, and fish.
  • Consider fluoride treatments.
  • If you are at risk, consider using additional oral hygiene aids, such as daily mouthwash, oral irrigators, or fluoride gels.