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Can A Cavity Form Immediately?

Updated: May 12, 2023

Do you want to know if you have a cavity because you ate ice cream last night or maybe you ate ice cream the entire week. How quickly do cavities grow? Perhaps you already have one but what should you do about it?

Table of contents:

How long does it take for a cavity to form?

A cavity can form within a matter of minutes the moment after you eat something sweet, which has sugar or carbohydrates in it. The bacteria that are present in your mouth start digesting the sugar almost immediately once it comes into contact with it.

The byproduct of the metabolized sugar is acid and this acid can eat through the enamel. Once it gets through the enamel it is officially called a cavity.

The beginning stages of a cavity are not only undetectable to the naked eye but also to dental x-rays as well. It may take up to 6 months before the decay can be visible to the naked eye and also for it to show up on the x-rays.

The reason is because these physical changes cannot be perceived until the cavity has damaged at least 25-30% of the enamel but just because we can't see it yet, it doesn't mean that it doesn't exist.

Therefore, even if you can get a cavity almost immediately you won't know about it until about 6 months later. That may not have been the answer that you wanted to hear but it is true. Despite the bad news, there are also some good news because the beginning stages of tooth decay actually don't grow that quickly.

How fast do cavities grow?

There are multiple factors that influence how fast cavities can grow and the speed at which it develops will also depend on the stage that the tooth decay is in.

Fortunately, once the cavity forms it does not keep growing without any impediments because our body naturally tries to reverse and stop the development of tooth decay. We call this process demineralization and remineralization of enamel. Yes, you read that correctly your body can either stop or reverse the cavities that are in the enamel of your tooth.

  • Demineralization is the process when the acid from the bacteria starts to wear through the enamel. If left untreated the decay will grow bigger and bigger over time until it reaches the nerve of the tooth. Once that happens you may experience unbearable tooth pain, which will ultimately result in either a root canal or tooth removal procedure.

  • Remineralization is the process when your body tries to stop or reverse the tooth damage from a cavity. It does this by using your saliva as a buffer to counteract the acid development by bacteria. The saliva is also a reservoir for fluoride, calcium, and phosphate which are the building blocks for repairing your enamel.

white decalcification spots
white decalcification spots

Factors that influence the speed of tooth decay development

  • Dietary habits. The more sugar that you eat, the faster the decay can progress and develop. Consequently, the less of it that you consume the slower it will grow. Bad eating and drinking habits can accelerate the growth of damage to your teeth.

  • Brushing habits. The more diligent you are with keeping your teeth and mouth clean the slower it will grow and develop. The reason is because if you brush and floss everyday, there will be less residual sugar in your mouth for the bacteria to metabolize and create acid. This results in less chances for the cavities to form. If you slip up on your oral hygiene routine, it would only encourage the bacteria to work more effectively.

  • Dry mouth. Your saliva acts as a buffer to neutralize the acids in your mouth. When you eat, the pH level drops into the acidic levels and that is how cavities form. Your saliva has a neutral pH of around 7 and it can buffer the oral environment to make it less hospital for bacteria to work. Therefore, if you have a condition that induces dry mouth, you may be missing out on this benefit and consequently get faster forming dental caries.

  • Fluoride toothpaste. This type of toothpaste has the ability to reverse small cavities so if you're using one, it can either slow down the growth of tooth decay or even completely stop it. How it works is when hydroxyapatite, a hard mineral which your tooth is made out of comes into contact with a fluoride ion, it combines into fluorapatite. This new molecular structure has increased hardness, increased stability, and increased resistance to acid attacks.

hydroxyapatite and fluorapatite

  • Hydroxyapatite toothpaste. This is the second type of toothpaste that has the Frequent dental check upsability to reverse tooth decay. Since it is made out of the same mineral that our teeth are made out of, simply brushing with it can help repair the acid damages to our enamel by the bacteria. Studies have shown that it can remineralize the cavitated enamel at a deeper and more homogeneous way.

  • Frequent dental check ups. If you go to your dentist more frequently such as being on schedule for your 6 month check up and teeth cleanings, the lower the chances of you getting tooth decay. Your dentist can catch the smaller cavities and let you know which areas to focus on and keep extra clean. You may also be able to adjust your habits in time to reverse them while they're still small.

Both types of toothpastes, fluoride and hydroxyapatite have the ability to reverse damaged tooth structures by decay. They are the only ones that are able to do that because other types such as charcoal, xylitol, and fluoride-free ones do not. We recommend that you use one of the two above and if you are anti-fluoride, then you should go with the hydroxyapatite.

The stages of cavities and how fast they develop

Tooth decay progresses through various stages and at each stage, they grow at different speeds. Some of the stages will be easier for the cavity to grow faster while other stages they will be forced to develop slower.

Tooth anatomy

  • Demineralization of enamel. The beginning stage which is almost undetectable to the naked eye and dental x-rays but once it has grown to a big enough size, you may be able to see it. When you can see it, what it looks like is a chalky white appearance on the enamel. At this stage, it grows very slowly and can take months before you can see it.

  • In the enamel. Your enamel is the hardest substance in your body, in fact it is harder than steel. For that reason the decay can grow extremely slowly and may take up to 2-3 years before it reaches the next stage of being in the dentin. While the cavity is in the enamel, it also has the potential to be reversed by fluoride or hydroxyapatite.

  • In the dentin. Once the dental caries has progressed into the dentin it will begin to grow much faster. In fact, it will take less than a year for it to reach the next destination, the nerve of the tooth. The damage cannot be reversed once it has reached this part of your tooth.

  • In the pulp. This stage is not good because it is usually when it starts to cause you pain. The damage from the decay is irreversible at this point and requires definitive intervention by your dentist. The development rate is very fast at this point and the cavity can travel down the tooth and into the bone in less than a few months.

  • In the bone. The final resting place for tooth decay because once it reaches here, it is considered a dental abscess. You've officially attained a tooth infection and you may be rewarded with facial swelling that can be life threatening if left untreated. You cannot delay treatment any longer even if you have high pain tolerance, you need to see a dentist immediately.

How to treat tooth decay

Permanent treatment for a cavity can only be performed by a dental professional. Depending on the amount of tooth damage caused by the decay, there will be a different corresponding treatment for it.

Small cavity

For minor tooth damage, a simple tooth filling will be sufficient to repair the damage. Your dentist will clean out the decayed parts of your tooth and then fill it back in with a composite filling, which is tooth colored. This is a simple one visit procedure and should only take about 30-45 minutes.

small cavity

Medium sized cavity

For a medium one, you may be able to treat it with either a larger filling or a dental crown. Both of these treatments are only valid as long as the bacteria haven't reached the nerve because once it does you will also need to treat the nerve. The cavity filling and porcelain crown can only fix cavities that have not reached the tooth pulp.

medium sized tooth decay

Large cavities

Decay of this size is reserved for describing damage that has reached the nerve of the tooth. This will require a root canal, which is complete removal of the tooth nerve. Afterwards, you will need a crown to protect the tooth.

large cavity

Extremely large cavity

If the damage has destroyed more than 75% of your tooth, it may not be saved or restored via conventional means. You will need the entire tooth removed. After the extraction you can replace the missing tooth with a dental implant.

Related content: Article about what cavities look like.

How to prevent it from forming

The best way to prevent them from forming is to alter your dietary habits and increase your oral hygiene efforts. If you can implement these two things, you should be able to prevent it.

Try to eliminate or reduce the amount of sugar and carbohydrates that you consume because they act as fuel for the bacteria to damage your teeth. If you reduce the intake, the decay will grow more slowly but if you manage to eliminate it completely, it may not grow at all.

As long as you stick with brushing and flossing habits that your dentist approves of, the chances of you getting tooth decay should be minimal. What we recommend is to brush for at least 2 minutes twice a day. You should also floss before you go to bed and use a mouth rinse too. Last but not least, don't forget to get your dental check ups every 6 months.

The Verdict

A cavity can form almost immediately but thankfully your body has defensive mechanisms in place that can slow down or even reverse the damage. If it is left untreated, it will continue to grow but the rate of development depends on which stage the decay is in. It could grow quickly or very slowly but you should still get it checked out by your dentist.

Our long island city dentist will diagnose and treat all types of oral health issues.



David Chen 200 x 200.jpg

About the author: Dr David Chen, DDS

Hello, I'm Dr Chen and I'm an actively practicing dentist in Long Island City, NY. I graduated from Columbia University College of Dental Medicine in 2016 but prior to going to dental school I was already working in the dental field. It's been more than a decade since I first got to know dentistry and let me tell you, time flies by quickly. Since then I've developed a fondness for writing, which is how this all got started!

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Medical Disclaimer:

This blog is purely meant for information purposes and should not be used as medical advice. Each situation in your mouth is unique and complex. It is not possible to give advice nor diagnose any oral conditions based on text nor virtual consultations. The best thing to do is to go in person to see your dentist for an examination and consultation so that you can receive the best care possible.

The purpose of all of this oral health information is to encourage you to see your dentist and to inform you of what you may expect during your visit. Due to the unfortunate nature of dentistry, there isn't really any true home remedies that will get rid of dental problems. Roughly 99.99% of them require in-person intervention by a healthcare professional.

Hint: That is the reason why you can't eliminate seeing dentists in your life!

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