Stages of Tooth Decay

  • Stage One: White Spots
  • Stage Two: Enamel Decay
  • Stage Three: Dentinal Decay
  • Stage Four: Involvement of The Pulp

Teeth are comprised of three layers: the enamel, dentin and pulp. Enamel is the outermost layer that helps protect your teeth from damage often caused by plaque bacteria, when not properly removed, that can lead to decay like cavities. Dentin lies right underneath the enamel, when exposed, this second layer is prone to sensitivity. The third layer is Cementum which covers the roots of the tooth. The pulp is the tissue within the core of your tooth which houses the nerves and blood vessels making it the most sensitive layer of the tooth. Tooth decay begins when the enamel begins to break down, creating pockets of decay on the surface of the teeth. Decay results from acidic damage to the tooth structure produced by bacteria that lives in plaque. Plaque is a soft sticky film formed by the protein found in one’s saliva metabolizing sugary foods left in the mouth. Some forms of tooth decay can be prevented by limiting sugary and sticky snacks, maintaining good oral care habits and regular trips to your dental professional. The following image can help you identify and understand tooth decay, so you can help prevent it.

Tooth Decay Stages

Stage 1: White Spots

The first stage of tooth decay begins when chalky white areas on the surface of the tooth appear due to the loss of calcium and build-up of plaque. These areas are caused by bacteria in the plaque metabolizing sugars from food consumed. The bacteria produces acid as a product of the metabolic process. The buildup of these acids causes tooth enamel to deteriorate, a process referred to as demineralization of the tooth surface. At this phase, tooth decay might still be reversible with the proper treatment—which should be discussed with your dental professional, such as using appropriate brushing technique, a fluoride toothpaste, and applying a topical fluoride treatment. One the best ways to prevent plaque buildup is to brush at least twice a day using a toothpaste with stannous fluoride and an electric toothbrush like the Oral-B iO. Its dentist-inspired round brush head expertly cleans tooth-by-tooth with micro-vibrations to deliver a professional clean feeling every day.

Stage Two: Enamel Decay

In stage two of tooth decay, the enamel starts breaking underneath the tooth’s surface. At this stage, if the natural remineralization process is unable to restore the proper enamel and minerals, it may cause a lesion to form within the tooth as acids are released over an extended period of time. As the decay persists, the surface of the tooth risks breaking, which is irreversible and can cause a jole or cavity to form. To better prevent enamel decay, it’s important remineralize or fortify the enamel with a fluoridated toothpaste before a cavity is formed.

Stage Three: Dentinal Decay

Stage three of tooth decay is known as dentinal decay. This occurs when the decay extends through the enamel into the dentin. The dentin is the part of the tooth that exists in between the enamel and the pulp. Once the decay reaches the dentin, it will spread quickly as the dentin is softer and less mineralized than enamel. When enough of the sub-surface enamel is weakened by the loss of calcium and phosphate minerals, the enamel collapses and a dental cavity is formed and may be visible to the eye. To avoid dentinal decay, a dental filling will most likely be required to restore the tooth, however, this must happen before the decay reaches the dentin layer.

Stage Four: Involvement of The Pulp

The pulp is considered the tooth’s center. It is made up of living tissue and it is where the nerve and blood supply are located. If the pulp of a tooth gets infected with bacteria, the exudate (pus) that forms can lead to an abscess which can be very painful. The gums and face may swell which can affect speech. At this stage, the most common courses of treatment are either root canal therapy which is then followed by the placement of a crown when caught early or extraction if the tooth structure is completely lost.

Popular For Tooth Health


Tooth decay is preventable. Establishing an oral care regimen that involves these preventive measures will help avoid tooth decay:

  • Adhere to a robust oral hygiene regimen –use toothpastes and mouthwashes with fluoride, floss daily and brush with an electric toothbrush. Studies show that brushing with an electric toothbrush like the Oral-B iO can help reduce tooth loss by removing more of the plaque bacteria that leads to decay. A strong oral care regimen can maintain your oral health and is regarded as the best preventative measure to take to avoid tooth decay.
  • Avoid a diet high in sugar as well as eating between meals. 
  • Drinking water can also help: keeping hydrated can help produce saliva to continue to nourish teeth enamel and to clean the mouth. 
  • Visit your dental professional for regular checkups will both help prevent tooth decay and maintain healthy oral care.

Source Yaacob M, ey al… Powered versus manual toothbrushing for oral health.Cochrane Database of Systematic Reviews 2014, Issue 6. Art. No.:CD00282. DOI:10.1002/14651858.CD002281.PUB3 Kantar.


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