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What Are the Stages of Tooth Decay?

Tooth decay is one of the leading types of preventable dental diseases and if untreated can lead to a loss in an individual's quality of life.1 In fact, tooth decay is the most common ailment in the United States—90% of adults over 20 have had dental caries at some point in their lives.1

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What Causes Tooth Decay?

Tooth decay is caused by bacteria in plaque that adhere to the teeth and break down sugars in foods and drinks.1 This breakdown produces lactic acid and leads to the loss of calcium phosphate from the structure of your teeth.1 These acid attacks can last for an hour before the minerals in your saliva helps the outer layer of your tooth to remineralize (or harden) again.2 Cavities most commonly form on the chewing surfaces of the teeth, mostly due to their irregular topography and natural nooks and crannies that facilitate the buildup of plaque and bacteria.1 However, any part of the tooth is at risk for decay.2

Tooth Decay Stages

Teeth are made up of multiple distinct layers.1 The outermost layer of your tooth’s crown is called the enamel. It is the hardest and most mineralized part of the tooth—even harder than bone!1 The second layer is called the dentin, which is softer due to its high percentage of water and collagen.1 The center of the tooth contains the third layer, called the pulp, which contains nerves and blood vessels that keep the tooth alive and provide sensation.1

As decay progresses, it can affect each part of the tooth, causing pain and eventually leading to tooth loss.

  • First Stage.
    In the early stages of tooth decay, the damage is reversable. The decay is confined to the tooth’s outermost layer, the enamel, and may be asymptomatic.1 Proper dental care such as brushing twice daily with a fluoride toothpaste, flossing and visiting the dentist is a good start in the effort to reverse the decay. A dentist or hygienist may apply a fluoride varnish to the tooth to help stop decay and strengthen or "remineralize" your tooth. They may also recommend further options based on an individual's needs.2
  • Second Stage.
    As the decay breaks through the tooth’s enamel via a cavity, it moves through the dentin and toward the pulp.1 A localized toothache is usually the first sign that tooth decay has progressed and caused a cavity.2 Because dentin is softer and less mineralized than the enamel, the decay can progress more quickly, leading to pain.1 At this point, compromised teeth may be treated or repaired with restorations (fillings) made of amalgam (silver), resin (tooth colored), porcelain or gold.1,2
  • Third stage.
    If tooth decay reaches the tooth’s pulp, it will start to affect the nerves and blood vessels.1 At this point, there is a risk of pain, swelling, and tooth loss.1 Treatment typically involves a root canal to remove the infected tissue and the restoration may be a cap or crown to replace and protect the missing and/or remaining tooth structure.1,2 If the tooth is too compromised, extraction may be the only treatment option.1

Preventing Tooth Decay

Adults and children can prevent tooth decay by practicing good oral hygiene to keep plaque from accumulating on the surface of the teeth. Take steps to protect your enamel with good oral hygiene like:1,2,3

  • Drinking water with fluoride
  • Avoiding or limiting sugary foods and drinks
  • Minimizing the number of snacks that you eat in between meals, which will help minimize the instances of acid attacks on your teeth.
  • Regular preventative dental visits—which may include sealants being placed on your molars to prevent bacteria from accumulating in the grooves of the teeth. Children may have additional fluoride varnishes painted on their teeth to help reduce the chances of decay.
  • Flossing to remove plaque and food from between the teeth, where a toothbrush is unable to reach.
  • Brushing your teeth thoroughly twice a day with a fluoride toothpaste, like Pronamel, which works to strengthen weakened enamel every time you brush. Pronamel helps minerals penetrate deep into the enamel surface, actively strengthening acid-weakened enamel, making it stronger, healthier and better protected against the effects of everyday acids.

Preventing tooth decay is relatively simple but requires diligence. By taking care of your teeth you can protect against enamel loss, cavities, gum problems (gingivitis) and tooth loss, and enjoy a healthier smile.

Source Citations:

  1. Tooth Decay Is The Most Prevalent Disease. National Library of Medicine. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6373711/. Accessed 8/2/22.
  2. Dental Decay. Oral Health Foundation. https://www.dentalhealth.org/dental-decay. Accessed 8/2/22.
  3. Cavities: What are They and How do we Prevent Them? Mouth Healthy. https://www.mouthhealthy.org/en/dental-care-concerns/how-do-we-prevent-cavities. Accessed 8/2/22.