What Does a Cavity Filling Look Like?

So you're told that you have a cavity and you need a "cavity filling". Your dentist proceeds to explain that the decayed portions of your tooth needs to be drilled out and then replaced by a tooth colored filling material.


The succinct explanation is great and all but you're probably curious as to what exactly the cavity filling process even looks like. After all pictures are worth a thousand words right?


Our purpose is to describe to you and show you with visual aid about what a cavity filling. We'll do it for every step of the filling process so that you know what to expect when you go in for your dentist appointment. You won't be walking into the world of the unknown once you finish reading all of this!



What the cavity filling looks like from start to finish on a molar:



What a cavity looks like before it gets filled

This was a real clinical case of a large cavity on the chewing surface of an upper molar that was done at our long island city dental office. We're going to cover this case from start to finish and this section will focus on what the before looks like.


Here is the before picture of what tooth decay looks like on said molar:


large cavity on chewing surface of an upper molar

This photo may not seem as bad because it just looks like staining in the grooves of the molar. There are dark brown lines in various parts of the tooth. To the untrained eye you may think that it's probably just a tiny cavity that needs an equally small filling.


Related content: Difference between a cavity vs a stain.


However, that couldn't be farther from the truth because if you look closely you can see a dark halo that is underneath where those brown lines are. There is a dark shadow that radiates out from the darkened lines. That is an indication that the decay is much larger underneath than what it appears.


Our thoughts are confirmed and verified by the dental bitewing x-ray that it is indeed a very large cavity. This is the x-ray of the same tooth in the photo above:


x-ray of large cavity filling on a molar before filling

On the x-ray you can see a big dark circle within the upper molar. You don't see that on any other tooth on this x-ray because that is the only one with large decay!


Basically anything that is solid on the x-ray will show up as white (radioopaque) and anything that is not solid will show up as black (radiolucent). Thus, when you start seeing black inside of objects that should be solid/white you're in trouble.


Learn more: What cavities look like on x-rays.


This is why it is important to take annual check up x-rays because you would've never known that you had such a large cavity. If you simply looked at your tooth in the mirror you would've just thought that it was staining. That all changes with the x-ray because even with the untrained eye, you can tell that one of the teeth looks different from all the other ones.


Additional info on what cavities generally look like:

  • Brown to black in color

  • Can appear on any surface of the tooth - top, sides, and in between

  • May be cavitated with a hole


Related content: We have a complete guide on what cavities look like.




What it looks like when the decay is being cleaned out

Now we're going to go through the cavity excavation process. All of the decayed parts of the tooth will be removed via a high speed drill with a ton of water. The high rpm drilling generates a lot of heat so water is needed to cool the tooth down to prevent it from burning to death.


This is still the same tooth as presented in the beginning of this article. Here is what it looks like after we drilled into the tooth.


large molar cavity - excavation step 1

As we drilled into the tooth, you can see that there was a lot more decayed tooth structure than you would've thought. This is shown by the fact that you can see a lot of brown colored material within the tooth. Cavities typically look brown in color as opposed to pearly white like healthy enamel.


You can also tell that the brown parts are decayed because the texture of it looks different. It looks flaky and gritty looking. The reason it looks like that is because it is actually soft. You can actually remove this decayed part by scooping at it with a hand instrument. You don't even need the drill to excavate this because it is so soft.


Healthy tooth structure on the other hand is hard and feels rock solid. That is why you can try scratching your enamel with your fingernail but it won't deform or put scratches in it. That is literally how hard healthy enamel should be.


Further excavation

When we continued to drill out the cavity, we started to see a lot more of the decayed tooth structure. When the hole is widened, we can truly see the extent of the cavity. It was definitely a lot bigger than we thought.


large molar cavity - excavation step 2

You can still tell that it is all decay because the color of the tooth structure is all brown. That is in stark comparison to the top of the tooth with healthy enamel that looks white.


Further and further excavation

Since there was still more decay, we had to excavate it deeper. As we removed more of the rotten parts of the tooth, we can see the color changing. The deepest part of the cavity is actually a dark black color.


large molar cavity - excavation step 3

The darkest part of the tooth is the most advanced and decayed part of it. That is basically how it works, small cavities start off as a light brown color but as it matures it becomes darker and darker.


Read more here to learn about the color of cavities.


Further, further, and further excavation

Since there was still more of the cavity left, we had to continue excavating and removing all of the rotten parts.


large molar cavity - excavation step 4

With further excavation, we can now see a dark circle at the base of the floor of the tooth. However, what is different in this photo is that the surrounding walls of that dark circle has changed to a more healthy yellow. It is no longer completely brown than before. This means that we're reaching healthy dentin on the periphery.


We continued to excavate a little bit more but had to stop because it started getting close to where the nerve was. you can tell that we're getting close to the nerve because as the arrows show on the picture, you're starting to see a little bit of pink showing through.


The pink color comes from the pulp and blood vessels within the pulp chamber. Since blood is red, it'll give a light pinkish hue when it shows through.


If we continue drilling, the patient would definitely need a root canal on it. As discussed with the patient, we decided to do an indirect pulp cap where we place a liner over the base of the cavity and then seal the entire tooth with a filling.


Sometimes this technique is successful while other times it does not but only time will tell. Nonetheless, there will always be a possibility that the tooth may still need a root canal in the future since the cavity filling was so deep.



What a finished cavity filling looks like

After all of the cavity was cleaned out, it is ready for the cavity filling part. It involves applying conditioner, primer, and bonding to the tooth. Then you fill it all in with a composite resin which is a tooth colored filling material.


Here is what the finished cavity filling looks like 6 months later:


finished cavity filling 6 months later

The color of the tooth looks significantly more pleasing than the previous where it had all of this brown colored embedded within it. Now it is a healthy and pretty white color.


This picture was actually taken 6 months later when the patient returned for their next dental check up. Why six months later you asked? That was because we forgot to take pictures after we finished but luckily they returned for their check up!


The great news is that they're not feeling any pain nor symptoms so the procedure at the moment is currently a success. We're hoping that it stays that way because things can always change.


Here is an x-ray of what the finished cavity filling looks like:


Finished cavity filling

If you compare this x-ray to the beginning one, you can see that all of that darkness or radiolucency within the top molar is now gone. It has been replaced by a white filling material that shows up as radioopaque on the x-ray.


You can even see the liner that we placed at the base of the cavity, which is the extra white looking material that is close to the nerve.




Takeaway

The appearance of a cavity filling goes through three distinct phases - before the cavity removal, during the removal, and after the filling.

  • The before part looks like any other tooth with decay. The decayed parts of the tooth are typically brown in color.

  • During removal, you can see a variety of shades of brown each signifying the particular stage of decay that each section is at.

  • After the cavity filling is completed, you should see a more aesthetic looking tooth without any brown coloring. The tooth should look pearly white now.


Overall the appearance of your tooth should have drastically improved after the completion of the cavity filling. That was our goal after all.

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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!