How long does it take for a cavity to form?

A person doesn't just develop cavities just overnight. It typically takes months, or possibly even years, for tooth decay to advance to a point where it requires attention.

That's because conditions aren't always right for the continuation of the tooth demineralization process (the action that causes cavities).

Cavity formation is a cumulative process.

As explained on our previous page, tooth demineralization only takes place when a combination of dental plaque (including the bacteria it harbors) and dietary sugars are present.

Fortunately, these conditions don't always exist. But each time they do, some tooth damage will occur.

Ultimately, there may be a point where the cumulative effect of innumerable episodes of demineralization will have finally resulted in the formation of a cavity that's advanced enough that a person's dentist determines it's in need of treatment.

Graphic #1.

Our illustrations to the right show how tooth decay has a chance to progress when dental plaque is present.

Then, once the plaque has been removed (brushed or flossed away), the decay process is stopped (although any tooth damage that's taken place still remains).

Every time this cycle repeats (which may be multiple times per day), the amount of tooth structure damaged by the decay process gets larger.

Remineralization - Another reason why cavity formation can take so long.

Beyond just demineralization, there's another important dynamic that can take place. If conditions are right, a tooth can undergo "remineralization."

Remineralization helps to counteract the damage created during demineralization. In effect, it's like tooth decay in reverse.

How does remineralization reverse tooth decay?

When conditions at a tooth's surface are non-acidic, the process of remineralization may take place.

When it does, minerals obtained from the oral environment (saliva, oral rinses, foods, beverages) are re-deposited onto the tooth, thus reversing, or at least minimizing, the damage that was caused by the cavity-forming demineralization process.

Remineralization will continue on until the repair is complete, or acidic conditions have returned (due to a renewed presence of dental plaque and dietary sugars).

It's a constant tug-of-war.

This back-and-forth action between demineralization and remineralization (both can take place several times a day) is one reason why cavities can take many months to form.

In some cases, remineralization can completely balance out the damage done by the demineralization process.

However, in those cases where there is heavy dental plaque accumulation or the person has a high sugar intake, the balance will likely tip to the side that favors tooth decay formation.

Graphic #2.

Our illustrations to the right show how decay formation can occur when dental plaque is present.

Then, if the tooth surface is kept plaque-free, the remineralization process can act to repair some of the damage that has been created.

White spots.

The earliest sign of cavity formation that you can actually see is termed a white-spot lesion. (This link will take you to our next page where they are discussed.)

All cavities require prompt attention.

Just because cavities can take an extended time period to form, doesn't mean that once they're diagnosed they don't need immediate attention.

The information above describes the initial transformation of a tooth from a state of good health to one where the presence of tooth decay can first be definitively diagnosed. This represents a stage where a cavity is still quite small.

If you have a situation where tooth damage is readily visible, or your tooth experiences sensitivity due to the presence of decay, your cavity is way more advance that what we are describing here. Delaying treatment will only worsen the outlook for your tooth's repair.