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Good oral hygiene is important to your overall oral health and well-being. But even if you take care of your teeth, you might notice some discoloration.

It can be tricky to tell the difference between a tooth stain and a cavity, especially since a cavity can cause light and dark spots. But a few differences can help you distinguish the two.

Some people might confuse a cavity with a stain and vice versa.

A cavity, also called tooth decay, is a permanently damaged area on the surface of your tooth, which may feel sticky.

Tooth decay can become bigger and deeper in time, and may create a hole in your tooth, so it’s important to call a dentist.

Stains may resemble cavities but seem to shrink or grow rather than steadily get bigger. They may even disappear after brushing your teeth or changing your diet.

But sometimes, the difference between the two isn’t so clear-cut. Let’s take a closer look at your teeth to help you identify whether discoloration is a cavity or a stain.

How far has it spread?

First, consider how widespread the stain appears. Is there a single spot on your tooth? Or is the entire tooth discolored?

When discoloration affects an entire tooth or surrounding teeth, it’s more likely a stain.

On the other hand, a single spot on your tooth or spots on your surrounding teeth in the following colors can often indicate a cavity:

  • brown
  • black
  • gray

Accompanying symptoms

A brown or black spot on a tooth isn’t the only sign of a cavity. Cavities also have symptoms that don’t occur with a tooth stain, including:

  • Sensitivity. With a cavity or tooth decay, you may have some sensitivity around your affected tooth. This includes sensitivity to hot or cold foods and drinks.
  • Holes in teeth. Cavities can not only cause spots but also lead to visible holes or openings in your teeth. A hole might start off small and then become bigger and deeper if the cavity goes untreated.
  • Tooth pain. Without treatment, tooth discomfort can progress from intermittent mild sensitivity to consistent pain. Pain occurs when cavities cause inflammation in your pulp, which is your nerve in the center part of your tooth. Discomfort can radiate to your jaw, ear, or cheek.

Residue from food and drinks is a common cause of tooth stains. These stains may appear suddenly and sometimes disappear just as quickly.

You might have staining if you drink a lot of:

  • coffee
  • tea
  • wines
  • sodas

Teeth staining can also occur after eating tomato-based foods. Often, reducing or cutting these out of your diet can help limit the appearance of stains.

Other causes of tooth stains include:

  • smoking and other tobacco use
  • aging: enamel may wear away with age, exposing yellow dentin underneath
  • too much fluoride consumed when your teeth were developing can cause white spots on your teeth
  • certain medications, such as antibiotics and antihypertensive medications
  • buildup of tartar (hardened plaque) on teeth

According to the American Dental Association, cavities develop over time when the acid in plaque slowly eats away at tooth enamel.

Plaque is a sticky film of bacteria that forms on your teeth. As your enamel weakens, holes or pits can develop in your teeth.

Risk factors for cavities include:

  • poor oral hygiene, such as not brushing or flossing regularly
  • dry mouth
  • acid reflux
  • eating too many sugary or acidic foods and drinks
  • insufficient fluoride

You have many options to remove stains and treat cavities to improve the appearance of your smile.

Tooth stains

  • Reduce or avoid foods and drinks that stain teeth to prevent further staining and discoloration.
  • Brush your teeth throughout the day. Brushing shortly after meals, snacks, and after drinking dark-colored beverages might prevent staining and discoloration.
  • Use at-home whitening treatments. Over-the-counter whitening treatment, such as whitening strips and whitening toothpaste, can help remove surface stains.
  • Consider professional whitening treatments. For deeper stains, at-home whitening treatments might be insufficient. Professional whitening treatments can speed the whitening process, resulting in more noticeable results.
  • Ask about dental treatments. Depending on the severity of discoloration, you might be a candidate for other dental procedures to whiten your smile.

Professional whitening treatments

  • Dental bonding can improve the color of your teeth.
  • Your dentist might suggest a dental crown if you’re also looking to restore a damaged tooth.
  • Dental veneers involve placing a porcelain shell over the front of your tooth.

Healthline

There’s no at-home treatment for a cavity, if you develop a hole in your tooth. You may be able to stop the early signs of a tooth decay, like a dark spot, by improving oral hygiene and avoiding sugary foods.

Schedule an appointment with your dentist as soon as possible if you have symptoms of a cavity, such as:

  • pain
  • holes in your teeth
  • sensitivity

If left untreated, a cavity can worsen and reach your nerve inside your tooth.

To protect your teeth and prevent nerve injury, your dentist will recommend a treatment based on the size and extent of the cavity.

Cavity treatments

  • Filling. The most common procedure for cavities includes removing the decay and filling your tooth with a special tooth-colored resin. This restores the shape and function of your tooth.
  • Crowns. For more serious cavities in which you’ve lost tooth structure, your dentist might recommend a crown after removing the decay. This involves placing a cap over a damaged tooth to prevent further decay.
  • Root canal. If a deep cavity causes nerve injury, you’ll likely need a root canal to remove a nerve.
Healthline

Here are a few tips to prevent further tooth discoloration and cavities.

Tooth stains

  • Brush your teeth at least twice a day with fluoride toothpaste, and even after meals and snacks.
  • Use teeth-whitening toothpaste to lift hard-to-remove stains.
  • Rinse your mouth with water after drinking dark-colored beverages like cola, tea, and coffee.
  • Floss between your teeth daily to remove food particles.
  • Drink beverages through a straw to reduce staining.
  • Try to reduce or quit smoking and avoid using other tobacco products.

Cavities

  • Brush your teeth at least twice a day, and floss at least once a day.
  • Schedule regular dental cleanings, at least twice a year.
  • Use mouthwash containing fluoride and antibacterial ingredients to reduce plaque and germs. Swish mouthwash in your mouth for at least 30 seconds.
  • Limit consumption of sugary and acidic foods and drinks.
  • Ask your dentist about sealants if you have a history of tooth decay. When applied to your tooth surface, sealants help strengthen teeth and protect them from decay.
  • Use a fluoride toothpaste to strengthen your teeth and prevent cavities.

A tooth stain and cavity can look similar, but they’re not the same. Although a cavity can cause a tooth stain, discoloration is often due to food and lifestyle habits.

Making a few adjustments can help reduce discoloration as well as the onset of cavities. These include:

  • brushing more often
  • rinsing your mouth with water
  • limiting certain foods and drinks

But contact your dentist for treatment if you have a cavity. Once you get a cavity, you may need dental treatment to fix it.