What is Tooth Decay? - Causes, Symptoms & Treatment

Instructor: Mary Ellen Ellis
Getting a filling or a root canal is no fun, but you may have to have these procedures if you suffer from tooth decay. Tooth decay may be one of the world's most common health problems, but it can be prevented with good dental care. Read on to find out more!

Tooth Decay and Cavities

No one likes going to the dentist, but a trip to see this tooth specialist is especially uncomfortable when you need to get a cavity filled or suffer through a root canal. If you have ever had a cavity, you know what this means: you literally have a cavity, a gap, or a hole in your tooth. This occurs when part of the tooth decays away. Tooth decay, also known as cavities or caries, is one of the most common, yet preventable health problems in the world.

What Causes Tooth Decay?

Tooth decay and cavity formation happens in a step-by-step way and it all begins with bacteria. Your mouth is teeming with bacteria, which live on the food you eat. When you eat, they eat, especially if you're not careful about brushing and flossing afterward. The bacteria surviving in your mouth form something called plaque, a sticky substance that you can feel on your teeth. If you don't clean this plaque off while it's still sticky, it will form a hard plaque on the surface of your teeth. This hard plaque gives bacteria a good place to live and thrive.

Plaque layered on to your teeth by bacteria is acidic. It eats away at the minerals in your tooth enamel. Enamel is a hard, outer layer that protects the interior of the teeth. Erosion by plaque acid weakens the enamel and causes it to develop small holes. This is the beginning of tooth decay and cavity formation. The gaps in enamel allow bacteria to get to the dentin, or soft, lower layer of your teeth, below the enamel. Dentin doesn't stand up well to acid and bacteria, so the little critters can move quickly from here to the pulp, the interior of the tooth.

The pulp of the tooth is surrounded by soft dentin, which is covered in hard, protective enamel. Tooth decay can go right down to the pulp.
tooth anatomy

Symptoms of Tooth Decay

A small cavity or the early stages of tooth decay may not present any symptoms, which is why it is important to visit the dentist regularly. As your teeth begin to decay more, or as a true cavity forms, you may start to get a toothache. The pulp of the tooth is full of nerves, which means deep decay can be quite painful. You may also experience tooth sensitivity or pain when you eat something hot or cold. You may see pits and holes in your teeth, as well as brownish stains.

Treating Tooth Decay

If you have had a filling, you know what treatment usually involves. A cavity needs to be filled to prevent it from getting worse and to bring you relief from the pain of tooth decay. If you're lucky and the damage isn't too severe yet, your dentist may give you fluoride treatments to strengthen and restore the enamel. Fluoride is an important mineral that makes enamel strong.

If your decay has progressed too far, a filling is the most likely treatment. The dentist will clean out decaying material and fill in the cavity with a resin, porcelain, or a silver amalgam.

Sometimes decay has gone too far for a simple filling to be good enough. Extensive decay may require a crown, a covering that replaces the top of your tooth. Once tooth decay has gotten as far as the pulp of the tooth, treatment requires a root canal, the most dreaded of all dental treatments. A root canal is a way to save a tooth that is badly damaged and involves drilling into the tooth to clear out the damaged pulp.

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