Depending on the extent and severity of the cavity, you may or may not be able to feel any differences by running your tongue over it. What you can feel with your tongue has a lot to do with the condition that the cavity is in.
Is the cavity small or is it very large? Is the tooth cavitated with a hole and is it chipped or not? Is the tooth infected with an abscess? Depending on the specific state that your tooth and cavity is in, it may feel different.
Condition of the cavity and what it feels like to your tongue:
Small tooth decay
Small cavities are typically undetectable to your tongue because they're not big enough to cause a physical change. The exterior and shape of the tooth will largely remain unchanged. However, you may notice some brown discoloration forming if you do indeed have a small cavity.
We'll show you what a couple of teeth with small cavities look like and explain why you won't be able to feel it:
Small cavity on the chewing surface
It is most likely impossible for you to feel a change in surface texture with your tongue for a small cavity on the chewing surface. The decay hasn't progressed enough to cause that type of physical change.
Basically the only thing that looks different about the tooth is the discoloration in the grooves where the cavity is located. The overall shape remains the same. We'd be hard pressed to say you can feel that with your tongue.
Small cavity on the side
It is definitely extremely difficult for you to feel a cavity on the side of your tooth with your tongue. The vast majority of this type of decay is located on the cheek side of your tooth. Your tongue is on the tongue side so it rarely if ever even goes over to that side of your mouth.
These cavities are really small so its not likely for your tongue to detect it. If you take into consideration that your tongue doesn't normally go there, the chances of you feeling it are pretty slim.
Small cavity in between the teeth
Your tongue definitely cannot feel small cavities in between the teeth. They're not even detectable to the naked eye because the only way your dentist knows is by taking an x-ray.
The point that we're trying to make is that the cavities that are in between the teeth are impossible for you to feel with your tongue nor with your fingers for that matter.
Related content: In case you were curious, we do have a lot more photos of what cavities look like. We've every possible one that you can think of it.
Can you feel a large cavity with your tongue?
Large cavities that are not cavitated, meaning that they don't physically have a hole in them, you won't be able to feel them. You can run your tongue over it all you want but if there isn't a physical hole, you won't be able to feel it.
In order to demonstrate what we mean by that, here is a case that we recently did. This is a picture of a molar with a big cavity. However, if you look at the picture, it looks normal and doesn't look like there is any decay at all.
Nonetheless, once you drill into the tooth, you'll see the decay right away. Here are two sequential photos showing the extent and depth of the decay.
Immediately after drilling into it, you start to notice a lot more brown which tells you that it is decayed.
As you keep drilling, it just gets bigger and bigger. None of this even looks remotely close to what the tooth showed at the beginning. The point that we're trying to make is that you can have LARGE cavities but not have a hole in them. Since there isn't a physical external change with the tooth, your tongue won't be able to feel it at all.
Decay tooth with a hole
The only cavities that you can feel with your tongue are the ones that are cavitated, meaning they have a physical hole in them. These type of cavities are typically very large because the decay has to eat through enough of the tooth for the integrity to be compromised that it forms a hole.
Here is a picture of a wisdom tooth with a big cavity that has a hole in it:
The picture above shows the tooth with a fairly large hole that is near the gum line. We would be hard pressed to say that your tongue can't feel that hole. In fact, you can even feel it with your fingers because you can probably stick your fingernail in there.
What it will feel like with your tongue:
The hole will feel jagged or sharp.
Can be rough feeling.
It may be tender if you stick your tongue in there.
Aside from that, any type of cavities that have holes in them can be felt regardless of their size. Most commonly, it can be teeth with cavity fillings in them that have broken down.
The picture above shows a tooth with an existing filling but part of it is missing. The missing section has become decayed which is why it looks black in the photo. That missing section can definitely be felt if you feel it with your tongue.
What it feels like:
Could be sharp or jagged feeling.
It'll feel like there is a hole in your tooth.
It won't feel smooth.
Abscessed tooth that is infected
Last but not least, an abscessed tooth that is severely infected can be felt with your tongue. The tooth won't feel any different on the exterior but it will feel tender if you touch it with your tongue.
If it hurts just by putting a little pressure on it, it probably hurts even more if you chew on it. If your tooth feels "off" like this, you may want to get it checked out. There could be some kind of infection with it.
It is not as primitive as it sounds because your dentist does use a percussion test to see if the tooth is healthy or not. For this test, we usually use the back end of the dental mirror and tap on the tooth. If the tooth is sensitive, it could be indicative of something going on with the nerve.
Here is a video demonstrating the percussion test:
Therefore, it is really not that different if you keep trying to push your tongue against the tooth. If it feels sensitive from just pushing pressure, it'll definitely react to being percussed by the end of a metal dental mirror handle!
Takeaway
The vast majority of cavities cannot be felt with your tongue at all. You can try to feel it but it won't feel like anything is amiss!
However, if you have large cavities that are cavitated it would be a different story. In that case you would be able to physically feel the hole that was created by the large decay. It'll feel rough, sharp, and possibly jagged. It may even feel sensitive while your prodding around in there with your tongue.
The take home point is that if you can feel the cavity with your tongue, it is most likely a very big one so you should go see your dentist. Nonetheless even if you don't feel anything you may still have a cavity, which is why you shouldn't skip your routine dental check ups.
All of the photos above were taken at our Long Island City, NY dental office! If you happen to need a cavity filling and you're close by, feel free to come on over. If you're far away you should find someone close to you because we don't want you traveling that far.
