How long does it take for a cavity to form? -
Cavities take a while to form.
A person doesn't just have a cavity develop overnight. It typically takes months, or possibly even years, for decay to advance to a point where it requires attention. (That's why your dentist feels comfortable enough only examining you every 6 months.)
It takes that long because conditions aren't always right for the continued progress of the demineralization process (the action that forms cavities).
How can you tell is something you see is a cavity?
In the case of relatively small lesions, you, the dental patient, are typically in a position where you can't tell what's what. Not everything that looks like it might be decay always is. Especially when it comes to small discolorations.
It will take an examination by your dentist to determine if something that seems suspicious is an actual concern.
Here are links to pages that discuss some of the things dentists look for when making an evaluation:
- White-spot lesions (the earliest visible sign of a cavity).
- How dentists check for cavities on x-rays.
Reasons why it takes time for cavities to form. -
A) Cavity formation is a cumulative process.
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 (demineralization, see link above) will occur.
Ultimately, there may be a point where the cumulative effect of innumerable small episodes of demineralization have finally resulted in the formation of a cavity that's advanced enough that a person's dentist determines that it's in need of treatment.
Here's basically what happens over the time frame that a cavity develops.
Cavity formation is the cumulative effect of repeated acid attacks stemming from dental plaque.
- When dental plaque accumulates on a tooth's surface, acids produced by the bacteria within it attack (demineralize) calcified tooth tissues (enamel and dentin).
- When the dental plaque is brushed away, the current attack is stopped but the damage it has caused remains.
- When more plaque accumulates, the acid attack resumes, adding to the damage that occurred previously.
- If ultimately the plaque is allowed to persist on the tooth's surface long enough (as in they don't brush as frequently or as well as they should), a full-fledged cavity will form.
B) Remineralization - The other reason why cavities can take a while to form.
To the rescue.
Beyond just demineralization, there's another important dynamic that takes place with teeth. If conditions are right, a tooth can undergo "remineralization."
This process helps to counteract the damage that occurred during the demineralization phase. In effect, it's like tooth decay in reverse.
How does remineralization reverse cavity formation?
When conditions at a tooth's surface are non-acidic, the process of remineralization has a chance to take place.
When it does, minerals obtained from the oral environment (saliva, oral rinses, foods, beverages) are re-deposited onto the tooth. The effect is one of reversing the damage that was caused by the 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.
The damage caused by tooth decay can be repaired by remineralization.
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 decay formation.
Our second graphic illustrates how cavity formation can progress when dental plaque is present.
But then, if the tooth surface is kept plaque-free, the remineralization process has a chance to take place and repair some of the damage that's occurred.
C) All cavities require prompt attention.
Just because cavities can take a long time to form, doesn't mean that once they've been 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 decay can first be definitively identified. This represents a stage where a cavity is still quite small.
If you have the situation where tooth damage is readily visible, or your tooth experiences sensitivity due to the presence of decay, your cavity is much more advance than what we are describing here. Delaying treatment will only worsen the outlook for your tooth's repair and health.
Menu for topic Tooth Decay -
- How to detect cavities on dental x-rays.
- How (and why) do cavities form? / The demineralization process.
- How long does it take for a cavity to form? / The remineralization process.
- White-spot lesions - The earliest visible sign of cavity formation.
- Decay syndromes - Baby-bottle caries. / Root cavities. / Xerostomia.
- How fluoride prevents cavities. / Side effects (fluorosis).
Related topics -
- Preventing cavities with tooth sealants.
- Using xylitol (a natural sugar alternative) to prevent cavities.