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What is a Tooth Cavity and What Does it Look Like?

I still remember when I got my first cavity. Nothing hurt, so I didn’t realize I had a cavity until much later when the tooth fell out (it was a baby tooth!). Cavities come in all shapes and sizes. Some hurt like heck, while others you wouldn’t even know they are there until the dentist shows you a picture or X-Ray of your tooth.

Let’s go through the ins and outs of a tooth cavity. Let’s figure out how to spot it, what caused it, and how to prevent it.

What is a tooth cavity?

Teeth are the strongest parts of our bodies. The enamel is made out of hydroxyapatite and is very strong. Teeth can withstand an immense amount of pressure and stay in great shape. They can chew on food for an entire lifetime and still be fine. But teeth do have kryptonite, and in general, it’s SUGAR. Sugar in small quantities is fine, but it can destroy even the strongest parts of our bodies over time.

We all have billions of bacteria in our bodies. In healthy individuals, the bacteria works along with our bodies to help us live a healthy life. Yet, if sugar is allowed to stay on our teeth for too long, it will erode our teeth. Sugar is not the only culprit, though. Sugar needs the help of bacteria to create an acidic environment.

Our bodies are at a slightly basic acidity, and all of our organs function best at that level. Our teeth prefer to be at a relatively neutral pH if we maintain that pH, the fluoride and various molecules are in harmony and keep our teeth strong.

If we allow sugars to stay on our teeth too long, some bacteria flourish. Certain bacteria in our oral cavity feed off those sugars, and they produce an acidic environment. This environment slowly eats away at the surface of our teeth. 

If we do not brush and floss the sugar properly, the bacteria stay on the teeth and keep the area acidic. The acids keep slowly eating away at the teeth millimeter by millimeter until eventually, we can see it.

Can you stop a cavity without drilling?

Yes, but it would help if you caught it very early. You will often hear the dentist say, “you have a small cavity that can be reversed with brushing and flossing.” This means the cavity is so small that the minerals lost by the acidic environment can actually be replaced with fluoride (that makes the teeth stronger), and removing the bacteria with a dental cleaning and an amazing electric toothbrush.

If you do these things and maintain amazing oral hygiene, you can reverse a small cavity. If the cavity has gone beyond the strongest layer of the tooth, enamel, and made its way to dentin or further, then you can’t reverse it. Once the cavity has gotten past the strongest layer of tooth structure, it will spread very quickly.

If you stop it early enough, you may need a small filling. This can be done with composite or porcelain or even gold!

Will I feel pain if I have a cavity?

You may or may not feel a cavity if you have pain when you drink hot or cold or sweets; that’s a pretty good indication you have a cavity. Yet, if the cavity is small enough, you may not experience any pain. Our jobs as dentists and educators are to show you where your cavity is. That’s why at all of our Thrive offices, we have intraoral cameras and X-rays that you can see on TV screens in every operation. We want to make sure you know where your cavity is and what we need to do to fix it. 

If your cavity has gone too deep, a normal filling will not do. If the cavity has eaten away a quarter or more of your tooth, you will likely need a tooth crown. Typically you will know if the cavity is deep as you can see it yourself. 

If on the tops of the teeth, the cavity will look dark. We use a tool called an explorer to see if the tooth is still healthy or sticky. If it’s sticky, you know that it has been eaten away by bacteria and the acidic environment.

Where do cavities normally form?

Most cavities form on the tops of teeth in kids, but in adults, most of them form in between the teeth. Why is that? Children tend to have spaces between the teeth, and the parents try to help them as best as possible with their oral health.

Most adults are terrible at flossing, so cavities tend to form in between teeth. If someone is prone to cavities, they likely received dental sealants to prevent fillings on the tops of the teeth, but nothing to really help cavities from forming in between teeth.

Risk factors for cavities.

  1. Tooth locations: If the teeth are crooked, they are harder to clean. Harder to clean means the bacteria can sit in those hard to reach areas longer.
  2. Sugar consumption: The more sugar you eat (or drink), the more food you give to the bacteria. The bacteria love sugar, so less sugar can help prevent cavity formation.
  3. Eating frequency: The more often you eat, the more often sugar is left on the teeth, and the more likely you are to get cavities.
  4. Bottle feeding: A real issue with some babies is allowing them to bottle feed at night or go to sleep with the bottle in their mouths. Milk, sugary drinks, etc., all have sugar that the bacteria love.
  5. Fluoride: Fluoride strengthens your teeth as it replaces certain minerals in the teeth that make them more resistant to acids.
  6. Plaque build-up: Plaque is leftover food particles mixed with bacteria. The longer it is on your teeth, the more likely you are to get cavities.
  7. Tarter and calculus: The dentist or hygienist can only remove the hard substance. Tarter stays on your teeth and harbors bacteria.
  8. Poor brushing: If you do not brush properly will not remove the bacteria that cause all the damage. You can get your regular 6-month cleanings, but you will get lots of cavities if you do not brush properly.


Cavities come in all shapes and sizes. It may hurt sometimes, or the cavity can be so small that you don’t even notice it. Cavities are caused by bacteria that feed off sugar and create an acidic environment. 

There are multiple ways to treat cavities, but the best way is prevention. If you brush and floss properly along with regular dental visits and maybe dental sealants, you can eliminate most cavities. 

Thank you so much for reading this, and if you have any questions or comments, please let me know!

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