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Small Cavity - Comprehensive Guide

Updated: Apr 19, 2023

A small cavity is one of the earliest progressions in the stages of tooth decay. It shares many of the same properties as any other cavity with the main difference being the size of the decay. As its name implies, it is smaller than all the other forms of tooth decay.

small cavity on premolar
small cavity on premolar

Nonetheless, don't let its size fool you because when it is left untreated it can progress and potentially deal some serious irreversible damage to your tooth. It will grow bigger and bigger until it gives you a toothache.

The good news is that at least you've caught it early. That means you do have a chance at redeeming yourself. When you decide to take action early you can potentially keep the treatment less complex and more conservative. It'll also be a lot less costly if you do so that'll save you some in the finances department!

The purpose of this article is to cover everything that you need to know about a small cavity:

How a small cavity forms in your tooth

Before a small cavity can form, demineralization of your enamel happens first and that is a natural part of the stages of tooth decay. This is when the surface of your tooth starts to weaken and lose minerals in its structure. It is the result of an acid attack from the bacteria in your mouth.

For all of this to occur, cavities require four factors to begin developing:

  • Bacteria. There needs to be bacteria present in your mouth because they're the ones that process the sugar to create acid that attacks the enamel.

  • Host. If you didn't exist, there would be no teeth for the bacteria to attack.

  • Substrate. Usually this means sugar because that is the fuel which bacteria use to create acid as a byproduct. Without it, they wouldn't be able to do any work.

  • Time. Cavities don't form overnight, it requires time for the acid to melt through the enamel and eventually form a cavitation.

The cavities will form as long as you have teeth for them to develop on. What makes it interesting is that no two of them are alike because they can form on any surface of the tooth. They'll spare no tooth in your mouth so it can be on any of them as well.

Here is where they can potentially develop:

  • Small cavity on the molars and the premolars.

  • On the side of the tooth, either on the cheek or tongue side.

  • Small cavity in front tooth. You definitely don't want anything to happen to the front ones. Imagine missing a front tooth.

  • Small cavity in between teeth. This usually happens if you don't floss often enough.

Basically, every single tooth in your mouth is a candidate for tooth decay. The only way to never get it is if you lost all of your teeth and became edentulous. In other words, if you had full complete dentures, you would never get cavities.

Is it normal to have tiny cavities?

It is not something that you want to have nor wish upon someone else but yes, it is normal to end up with tiny cavities if you consume a lot of sugar. It is also amplified if you don't keep up good oral hygiene because that can cause you to develop them even faster.

Getting them is like cooking with a recipe. As long as you provide it with all four of the factors from the above section, you will surely develop them. That much is certain.

With that being said, it is not so straightforward as if you ate sugar you will get a decayed tooth. If you maintain impeccable oral hygiene everyday, you can minimize the chances of getting it. Sometimes if you are lucky, you can completely prevent it. That is why it is important to brush twice a day and go in for your biannual deck check ups!

Is this a serious condition?

Getting tiny cavities is not serious in the sense that you need to drop everything that you're doing in order to take care of it like a dental emergency. The truth is that it most likely won't cause you any pain any time soon. You may get some sensitivity such as when you eat sweets but that would be about it.

However, that doesn't mean that you should just ignore it nor delay treatment for it. Tooth decay will grow when it is left unattended. If that doesn't motivate you, perhaps additional out of pocket expenses will. Large cavities will require more complex treatment and that will also mean it will be more expensive as well.

Our recommendation is to give it prompt attention. If you take care of it while it is still small you can keep treatment more conservative and less costly. Your future self and your bank account will thank you for it!

What does a small cavity look like?

They look similar to other types of decay with the main distinguishing factor being their size. As its name implies, this type of tooth decay is small. That means medium and large sized decay would not qualify.

small cavity on top of molar (black dot)
small cavity on top of molar (black dot)

Physical appearance:

  • Brown to black in color but the color saturation may vary.

  • Small in size.

  • May appear on any surface of the tooth; top, bottom, side.

  • May or may not have an actual hole in the enamel.

  • Texture could be hard or soft.

These are all signs that you can visually see on either the top or sides of the tooth. If the cavity is located in between the teeth, you wouldn't be able to see it at all. The only way to detect those are with dental x-rays. Without the radiographs, even your dentist wouldn't even be able to tell unless it is a large cavity. Small decay in between your dentition are undetectable to the naked eye.

Once again that just exemplifies the importance of not skipping your annual dental x-rays. Even if you are at low risk for caries, it is still a good idea to get them once in awhile just in case something is trying to form. Catching it early will result in less costly treatment.

Dental x-rays

Unfortunately not all of the small cavities will show up on the x-rays. In fact, only the small ones that are in between the teeth will show up. It has more to do with the angulation and the thickness of the tooth at that junction which permits it to reveal itself on the x-ray.

cavity in between the premolars on x-ray

The x-ray above shows small decay in between the two upper premolar teeth. There is also a small one in between the bottom left premolar as well. What the cavities look like on x-ray is darkness, which we refer to as radiolucent. These are the only types of small caries which you'll be able to detect on radiographs.

Unfortunately for the tiny decay that are on the chewing surface of a tooth or on the side of it, they will not show up. This has to do with where they are located and the angulation of the x-ray. They're practically located at the thickest portion of the tooth and with how we position the x-ray machine, it makes it impossible to detect them.

The fortunate news is that your dentist can easily detect them via a clinical oral examination. They can not only touch them but also visually see them. This is in contrast to the in between ones where they are undetectable to the naked eye without x-rays.

Therefore, there are pluses and minuses for detecting decay on various surfaces. This is why a complete dental exam requires multiple methods of diagnosis!

Related content: Aside from just small ones, here is an article about what cavities look like.

Can a tiny cavity heal itself?

The answer would be it depends on how tiny or small this cavity is but the determining factor is actually where it is located. Cavities that are located solely within the enamel do have the potential to heal itself but once it grows past that and into the dentin, it becomes irreversible. Once that happens you can try as much as you want but it'll never go away.

human tooth diagram with all of the layers
Credit: KDS4444

When we say that it can heal itself, it does not do so on its own. It requires intervention from you in order to actually reverse itself. It can do so with either fluoride or hydroxyapatite, which you can find in toothpastes.

According to this study, both types of toothpastes were equally as effective in remineralization the carious lesions. The newer product, hydroxyapatite was found to be not inferior to the traditional fluoride detrifice.

What the study also found was that the remineralization of the lesion was most effective at the outermost 30 μm. That is one of the reasons why if your small cavity has extended beyond the enamel, the remineralization capabilities of these toothpastes would not be able to reach it.

Thus, the answer is that yes a small cavity can go away but not all on its own. It requires you to practice good oral hygiene by brushing with either a fluoridated or hydroxyapatite toothpaste. It also helps if you minimize the sugar intake so that the cavity doesn't get worse.

How to treat small decay

There are two ways to treat a small cavity and both of them will get rid of it permanently.

  • Reverse it with fluoride or hydroxyapatite. This is the most conservative way, which we described in the previous section above. Just be aware that it only works for the lesions that are located solely in the outermost enamel layer.

  • Cavity filling. Alternatively if you're unable to reverse it on your own or it seems to be growing bigger, you will need the help of a dentist. By drilling out the decay and filling it with a tooth colored composite, you can get rid of the decay.

What to expect for a small cavity filling procedure:

  1. Apply the pre-numbing gel to the area to be anesthetized.

  2. Administer the local anesthetic Lidocaine to numb the tooth.

  3. Excavate the cavity by drilling it out.

  4. Apply conditioner, primer, and bonding to the tooth.

  5. Place a liner at the bottom.

  6. Start packing in the composite resin.

  7. Light cure to harden and make the filling material set.

  8. Adjust the bite to get the occlusion right.

  9. Polish the tooth and you're all done!

The entire procedure sounds like a mouthful but it shouldn't hurt at all because you'll be thoroughly numb from the local anesthetic. If you do feel anything during the procedure, just raise your left hand and your dentist can always administer an extra dose of the lidocaine.

How long does it take to fill a small cavity?

Since small cavity fillings are the least complicated filling procedure, they consequently take the least out of time to complete at least compared to their larger counterparts. You can expect the entire treatment to take only one visit and about approximately 30 minutes total.

The reason it takes that long is because each step of the procedure requires time.

  • The anesthesia to numb the tooth takes about 5 minutes.

  • Drilling out the decayed parts will take about 10 minutes.

  • Filling in the tooth then takes another 10 minutes.

  • Finally adjustment the bite and polishing it will take the last 5 minutes.

What can you eat after the procedure?

There aren't any restrictions as to what you can eat after the cavity filling procedure. You may choose to consume whatever your heart desires.

The only thing you need to watch out for is that you shouldn't eat anything while you're still numb. According to this study, it will take approximately 2-3 hours for the anesthesia to fully wear off. In other words, you should wait 2-3 hours before eating anything after a tooth filling procedure.

It isn't necessarily that you can't physically eat because you sure can. It is more so for your own safety because you may end up chewing up your lip, tongue, or cheeks since you're so numb. You'll injure yourself and not even realize it! However, you will certainly feel the pain once the numbness wears off.

How much does it cost to do a cavity filling?

The average cost for a small one surface cavity filling in the United States is $190.90 without any dental insurance. However it may range from as low as $144 to as high as $260. This is all according to the latest survey of ADA (american dental association) fees.

However if you do have insurance, it will certainly bring the cost down. Depending on your specific plan, it may cover a percentage of it. The most common amount that we see for restorative work is about 80%. What that means is that your out of pocket cost would only be 20%.

The final cost would be dependent upon your insurance plan and whether or not you are seeing an in-network or out-of-network dentist. Depending on which one you see, it can affect the expenses greatly.

How do you prevent tooth decay from coming back?

After you get that small cavity filled, it does not make it immune to future cavities. It can always come back and cause new decay on a different spot on the tooth or even underneath the old cavity filling. When the latter happens, we call it recurrent decay.

This is why it is important to practice good preventative measures so that the situation above does not happen to you. The best thing to do is to control your diet and practice good oral hygiene. You just need to be diligent about it on a daily basis.

How to prevent cavities:

  1. Minimize the amount of sugar intake in your diet. Absolute avoidance is even better.

  2. Brush your teeth for at least 2 minutes twice a day.

  3. Use a fluoride or hydroxyapatite toothpaste to help reverse cavities.

  4. Definitely floss before you go to bed and use a mouthwash when you can.

  5. Get your dental check up and cleaning every 6 months.

If you manage to do all of the above, you should be able to keep the caries away! Remember, it is not a once and done deal because you need to maintain all of this for the rest of your life. If you lapse, the tiny cavities can and will return to take advantage of it.


The main difference between a small cavity and their larger counterparts is due to its size. The rest of the properties remain the same since decay is still decay. Even though it is tiny, you don't want to leave it untreated because it can grow and progress.

Larger cavities will require more complex treatment and also an increase in cost. Therefore, just because its small and they don't hurt, you shouldn't leave them unattended!

That is the advantage in catching the cavities when they're small because they usually require only conservative treatment due to it's smaller size. Typically a cavity filling will be more than sufficient to get rid of it. That is actually a big motivator to getting tiny cavities taken care of because it keeps the procedures less complicated and also less costly.

That is not only better for you but also better for your finances.



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!

Association Memberships:

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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