Tooth Decay: Symptoms, Stages, Causes, and Prevention

Posted on April 1, 2021

Tooth decay is a pressing topic across all ages.

42% of children ages 2 to 11 have cavities in their baby teeth, and 21% of children in that age range already have developed them in their permanent teeth.

For adults, 92% of us have experienced tooth decay.

Here’s the good news: even if you have a history of dental issues, you can skip the headache (and the toothache) moving forward, stopping cavities before they start.

Let’s take a look at the symptoms, stages, causes, and prevention techniques you need to know to send away tooth decay.

What is tooth decay?

Tooth decay refers to small spots where tooth enamel or dentin has been eaten away by acid, eventually growing and spreading throughout the tooth. Advanced tooth decay, also called cavities or dental caries, is the number one preventable disease in the world.

This decay process can happen on any part of the tooth: on the smooth surface of the sides, at the root, between teeth (interdental spaces), or on the ridges at the top.

Tooth decay damages and eventually begins to break down the teeth if left untreated. Even a small cavity or spot is worth taking seriously.

If you’re caring for your children’s teeth, it’s crucial to be proactive about cavities. The Centers for Disease Control and Prevention (CDC) calls it “the most common chronic disease in children ages 6 to 11.”

Everyone from nursing children to dentists ourselves can develop tooth decay. It’s essential to understand how a cavity can develop so you can catch and prevent its spread.

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How does a cavity develop?

To understand how a cavity can develop and make its way through your tooth, we need to know how a tooth operates. Let’s talk about the four layers of teeth, according to the American Dental Association (ADA):

  • Enamel. This is the hard outer layer that you can see on the surface of your tooth. It is the hardest substance in your body, made up of several minerals.
  • Dentin. This second layer of the tooth contains the tiny tubules and living tissues that communicate with the nerves located farther inside the tooth.
  • Cementum. The cementum is also quite hard, covering the bottom half of the tooth’s root and anchoring the tooth in the gum.
  • Pulp. The pulp is softer than the other layers and is found in the middle of the tooth. It acts as a casing for the nerves, blood vessels, and connective tissue.

In the beginning stage of tooth decay, a layer of clear, sticky film called dental plaque builds up and coats the tooth. Plaque is teeming with pathogenic (disease-causing) bacteria that produce acids that can damage your teeth and cause gum disease.

Unfortunately, this acid that comes from plaque eats away at the minerals that make up the enamel. Over time, it can begin to demineralize and eventually break down the enamel layer, continuing to cause damage deeper into the tooth.

Symptoms of Tooth Decay

It’s relatively easy to see or feel dental cavities forming once they progress throughout the tooth. But your best bet is to catch this decay as early as you can before tartar build up and damage become irreversible.

Knowing the symptoms of tooth decay and catching it in the early stages can save you from more intensive procedures, possible infection, and bigger dental bills.

The signs and symptoms of tooth decay include:

  • White spots or a chalky appearance on the surface of the tooth
  • Small holes on the surface of the tooth
  • Tan, brown, or black spots
  • Sensitivity to hot or cold food and beverages
  • Pain and swelling at a tooth
  • Bleeding or swollen gums
  • Discomfort when chewing
  • Persistent bad breath
  • Unpleasant taste in the mouth

So, knowing the symptoms, how is tooth decay diagnosed?

Tooth decay can only be accurately diagnosed by a dental professional. While you may see the symptoms, it’s tough for an untrained eye to tell the extent of the damage and the best treatment plan. Your dentist will use a physical examination and, in many cases, x-rays to diagnose cavities and determine the appropriate treatment.

Head to the dentist if you notice any of these symptoms. The sooner you can catch tooth decay, the better. This is one of the many reasons it’s wise to keep your dental checkups scheduled every 6 months.

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Tooth Decay Stages (with Pictures)

What are the stages of tooth decay? Tooth decay has 5 stages, growing more severe as it progresses. Here’s how it develops, from the initial stages to the end result, if left untreated:

  1. Demineralization. In the first stage of tooth decay, acid produced by the bacteria in plaque begins to break down the minerals that make up tooth enamel.
  2. Decaying enamel. Once the enamel has lost its minerals, it is left weakened, and bacteria can eat through the enamel of the tooth, causing a hole that will need to be filled.
  3. Decaying dentin. The bacteria has passed through enamel and now begins to damage the dentin layer. In this stage, increased sensitivity in the tooth may occur since it is linked to the tooth’s nerves.
  4. Damage to the pulp. After the bacteria has penetrated through the dentin layer, it has now reached the sensitive pulp. This may cause swelling and more acute pain as the bacteria irritate the nerves inside the tooth.
  5. Abscess. At this stage of tooth decay, the pulp is infected. A pocket of pus can form at the base of the tooth, called an abscess, and pain may spread into the jaw, swollen lymph nodes, or fever. If you have an abscess, do not wait. Go see your dentist immediately to keep the infection from spreading.

While advancing tooth decay can cause significant pain and trouble, a tooth abscess is dangerous to your overall health. Untreated abscesses can cause life-threatening complications.


There are many possible contributors to decay in the teeth, or dental caries. These include, but are not limited to:

  • Consistent snacking. Food can cling to the teeth between meals, especially on sugary foods and carbohydrates that break down into food for oral bacteria.
  • Poor oral hygiene. It’s important to brush and floss regularly and for your kids to do the same. I recommend brushing 3 times a day and flossing at least once.
  • A consistently dry mouth. This can be caused by mouth breathing at night, stress, or even overusing mouthwash.
  • Acid reflux disease. Stomach acid can enter the mouth and cause wear and tear on the enamel.
  • Medical conditions. Some forms of treatment for cancer in the head and neck can increase the likelihood of dental caries.
  • Improper nutrition. You need a healthy intake of vitamin D3, vitamin K2, and calcium to build healthy enamel. For children, these nutrients also support jaw development and can help reduce the risk of orthodontic problems.


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As you can see, many of these causes of tooth decay are preventable with intentional oral care.

Risk Factors

Interestingly, not all mouths, or even all teeth, are at the same risk for decay.

These factors make teeth more susceptible to bacteria:

  • Location. Your molars are often harder to reach when brushing. They also have many grooves and places for food to hide. The back teeth are more likely to experience decay.
  • Age. Young children under 12 and older adults are more likely to have tooth decay than other groups.
  • Brushing and flossing. Not brushing 3 times a day after meals or flossing regularly raises the risk of tooth decay.
  • Old dental fillings or devices. If fillings and crowns are not looked after, they can become weaker and create a place for decay to build underneath.

What are the long-term effects of tooth decay?

The long-term effects of tooth decay include abscesses, potential root canals, and even tooth loss. Gum disease can also occur when plaque and tartar go unchecked — cavities and gum disease run hand in hand.

What happens if tooth decay is left untreated? Tooth decay that is left untreated has the potential to continue to spread throughout the whole tooth. It can continue its movement to infect the mouth and head, or even the jawbone in the late stages. These later stages pose a risk to both your dental and whole-body health.


Can you fix tooth decay? Yes, there is a treatment for each stage of tooth decay. No matter what stage of tooth decay you are experiencing, let a dentist help. We can alleviate discomfort, find solutions, and put your mind at ease.

From fillings to extractions, you or your child will be numbed and comfortable through the procedure. Don’t let fear of pain stop you from treatment. Here are the most common treatments for tooth decay.

1. Reversal

When tooth decay is caught early on, it is possible to reverse it. My top recommendations are diet changes to incorporate more vitamins like D3 and K2 and minerals like calcium for strong teeth.

In addition to a diet overhaul, oral probiotics, tongue scraping, and nasal breathing help reverse tooth decay. I also recommend oil pulling and certain dietary supplements, depending on the situation.

Another great option to rebuild enamel is hydroxyapatite toothpaste. Hydroxyapatite is the primary mineral that teeth are made of, and brushing it on can help to restore the structure of your teeth.

What is the best toothpaste? The best toothpastes to restore enamel are Risewell (use code: DOCTORSTACI for 10% off) or Boka (use code: DOCTORSTACI for 20% off); I highly recommend both for their hydroxyapatite content and fantastic flavors.

Fluoride toothpaste is associated with more systemic risks to children than HAp toothpaste, but it can also support remineralization of the teeth to support cavity reversal in certain high risk situations, although I find hydroxyapatite to be superior and without the worry..

2. Fillings

Once bacteria have broken a more significant hole into the enamel, fillings will be necessary. Your dentist will clear out the area of decay and then place a composite material into the tooth to fill the gap.

3. Pulpotomy/Root Canal

What is a root canal? A root canal is a procedure that removes infected pulp from within the tooth before cleaning and filling the cavity inside the tooth. After this is complete, a crown is placed on top of the tooth.

A root canaled tooth is essentially “mummified.” It is no longer living, changeable tissue but cut off from the body’s blood supply.

In baby teeth, this procedure is called a pulpotomy and removes less pulp than a root canal to avoid excessive damage to the tooth.

4. Extraction with Implant

In more severe tooth decay cases, it may be necessary to extract the tooth if the infection has spread or irreparably damaged the tooth. After removing a permanent tooth, it’s possible to have a new, false tooth implanted into the jaw, maintaining the health of the mouth. Primary, or baby, teeth do not need replacement but may need a space maintainer.

However, if a child loses a permanent tooth, kids generally cannot have dental implants until they turn 17-18 yo (because the jaw and palates continue to grow). Instead, talk to your dentist about a spacer to prevent orthodontic issues.


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How to Prevent Cavities

We’ve talked about diet and brushing directly after meals, but there’s much more you can do to be proactive against cavities.

You may be wondering how to prevent cavities, or more practically, “How can I prevent tooth pain?” You can prevent tooth pain with the following tips to avoid cavities and minimize tooth decay:

Managing Mouth Breathing

Breathing through the mouth can cause tooth decay, not to mention facial development issues in children. In fact, chronic nighttime mouth breathing can present in children similar to ADHD.

Try mouth taping overnight for adults. Bring a child who breathes through the mouth regularly into their pediatric dentist to check for underlying issues and discuss treatment with your pediatric dentist. A visit to other specialists like an ENT or myofunctional therapist may be indicated.


Flossing daily removes bacteria that your toothbrush can’t reach, preventing hardened plaque called tartar from attaching to the teeth.

Tongue Scraping

Tongue scraping can help remove the aggressive bacteria from the mouth and balance out the oral microbiome. I’ve found that kids love the silliness of tongue scraping, which is a bonus!

Oral Probiotics

There are good bacteria in your mouth, not just bad ones, and they help fight off tooth decay. Taking oral probiotics can increase the ratio of good bacteria in your mouth, aiding in the battle against cavities.

Other Approaches

Many dentists will recommend dental sealants or fluoride treatments (fluoride varnish) to prevent cavities. However, studies have shown that hydroxyapatite is as effective as fluoride but with fewer side effects.

Dental sealants are an option for some families but merit an in-depth conversation about what materials they’re made of and what technique is used to ensure bacteria or early cavities are not getting trapped underneath as these sealants are sitting in your child’s mouth indefinitely and should be taken very seriously.

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When to See Your Dentist

How can I remove tooth decay myself? Unfortunately, you can’t remove tooth decay yourself. Come see your dentist, and some x-rays and a quick conversation will give you a plan you can smile about.

The best way to prevent tooth decay is to practice prevention and see your dentist every 6 months. We’re here to help, and we can catch demineralization before it progresses. We want to see you empowered, not afraid, so you can live without tooth decay.


  1. Colard, T., Falgayrac, G., Bertrand, B., Naji, S., Devos, O., Balsack, C., ... & Penel, G. (2016). New insights on the composition and the structure of the acellular extrinsic fiber cementum by Raman analysis. PLoS One, 11(12), e0167316. Full text:
  2. Ghannam, M. G., Alameddine, H., & Bordoni, B. (2020). Anatomy, Head and Neck, Pulp (Tooth). StatPearls [Internet]. Full text:,each%20other%27s%20development%20and%20survival.
  3. Ratcliff, P. A., & Johnson, P. W. (1999). The relationship between oral malodor, gingivitis, and periodontitis. A review. Journal of Periodontology, 70(5), 485-489. Full text:
  4. Hicks, J., Garcia-Godoy, F., & Flaitz, C. (2004). Biological factors in dental caries: role of saliva and dental plaque in the dynamic process of demineralization and remineralization (part 1). Journal of Clinical Pediatric Dentistry, 28(1), 47-52. Abstract:
  5. Selwitz, R. H., Ismail, A. I., & Pitts, N. B. (2007). Dental caries. The Lancet, 369(9555), 51-59. Abstract:
  6. Robertson, D., & Smith, A. J. (2009). The microbiology of the acute dental abscess. Journal of medical microbiology, 58(2), 155-162. Abstract:
  7. Erazo, D., & Whetstone, D. R. (2020). Dental Infections. StatPearls [Internet]. Full text:
  8. Islam, B., Khan, S. N., & Khan, A. U. (2007). Dental caries: from infection to prevention. Medical Science Monitor, 13(11), RA196-RA203. Abstract:
  9. Estrela, C., Holland, R., Estrela, C. R. D. A., Alencar, A. H. G., Sousa-Neto, M. D., & Pécora, J. D. (2014). Characterization of successful root canal treatment. Brazilian dental journal, 25(1), 3-11. Abstract:
  10. Surtel, A., Klepacz, R., & Wysokińska-Miszczuk, J. (2015). The influence of breathing mode on the oral cavity. Polski merkuriusz lekarski: Organ Polskiego Towarzystwa Lekarskiego, 39(234), 405-407. Abstract:
  11. Bordas, A., McNab, R., Staples, A. M., Bowman, J., Kanapka, J., & Bosma, M. P. (2008). Impact of different tongue cleaning methods on the bacterial load of the tongue dorsum. Archives of oral biology, 53, S13-S18. Abstract:
  12. Shakib, P., Rouhi, S., & Zolfaghari, M. R. (2020). The role of probiotics in preventing dental caries. Plant Biotechnology Persa, 2(1), 55-58. Full text:
  13. Amaechi, B. T., AbdulAzees, P. A., Okoye, L. O., Meyer, F., & Enax, J. (2020). Comparison of hydroxyapatite and fluoride oral care gels for remineralization of initial caries: a pH-cycling study. BDJ open, 6(1), 1-7. Full text:

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