What causes tooth decay?

Tooth decay, also called cavities or dental caries, is caused by plaque and bacteria buildup. When bacteria escapes brushing and flossing, it can colonize and form a soft sticky substance called plaque. Since plaque is clear and attaches fiercely to teeth, it can sometimes go unnoticed.


When the bacteria in plaque mix with the sugars and starches you eat, acids form and destroy the tooth enamel, which creates a hole in the tooth called a cavity. If left untreated, a cavity can extend into the dentin or tooth pulp, affecting the tooth nerves and causing pain and infection.

Why do I need a filling?

Only a dentist can halt the progression of a cavity by removing the infection and placing a filling. Brushing and flossing can prevent cavities, but once a tooth has decay, it will continue to progress into a larger infection. A minimally-invasive procedure, fillings prevent the decay from reaching the inside of the tooth. Once the bacteria reaches the center of the tooth, called the pulp, where the nerves are located, a root canal treatment is necessary to remove the infection.

How can I prevent my children from developing cavities?

Help your children brush their teeth twice a day using children’s toothbrushes and toothpaste, and schedule dental examinations and cleanings for them every six months. At a dental cleaning, a hygienist can also apply a sealant to block out bacteria from hard-to-clean teeth. Establishing good dental habits early is imperative to ensure your child’s continued successful oral hygiene into adolescence and adulthood. You can read more about how to maintain your child’s oral health on our prevention tips for children page.

What foods contribute to tooth decay?

A catalyst for plaque development, sugar and bacteria can collect in the mouth and form an acid which wears away the tooth enamel and causes decay. Therefore, foods like cookies and candy have been cited the most for causing cavities. It is important to know, however, that sugar content is not limited to the most obvious offenders like sweets and soft drinks. Starches and carbohydrates like white bread or crackers are also hospitable to bacteria after fermenting into sugar. Additionally, pay attention to the amount of sugar in fruit drinks; some artificial fruit beverages include high amounts of sugar as well as tannins, which stain teeth.