How Do Teeth Get Cavities?

Our teeth are made up of what is called Calcium Hydroxyapatite, which is a complex form of calcium and phosphate. When we eat foods with fermentable carbohydrates or sugars there is a bacteria that may be attached to the tooth (in the form of plaque) called Streptococcus mutans that converts the food to acid, which demineralizes the enamel or tooth surface. Every time we have any challenge (meaning anything we eat or drink) with sugar or carbohydrates there is a 20-minute interval in which acid is produced by the bacteria that weakens or eats at the tooth surface. The saliva in our mouths bathes the tooth with calcium and phosphates so it tends to minimize the acid attack. Sometimes we lose the battle if the teeth are not cleaned efficiently enough. It is important to know that in our saliva is an enzyme called amylase that converts certain carbohydrates to sugar, which is the main source for the bacteria to then release this acid production.

In terms of common sense things we can do to prevent decay, it is important to note that it is not the total amount of sugar or carbohydrates that increases decay potential but rather the frequency of the acid attacks. Every time we have some sugar or certain carbohydrates we get 20 minutes of acid production and the bacteria remain on our teeth. To put this in perspective, if one person has 2 ounces of sugar every day, all at once, and another person has 1/10 of an ounce of sugar, but it is broken up over 9 times throughout the day, then the latter person would have 9 acid attacks compared with only one for the person consuming more sugar. The person with more acid attacks would thus be more susceptible to decay.

Brushing one’s teeth can remove 60% of the plaque (bacteria) off of the teeth, but without flossing daily there is potential for 40% of the tooth surfaces to be subject to decay in between the teeth.  That is why people who floss regularly will have less decay in between their teeth than those who do not.

In a future article we will go into the different types of decay.

(The information contained in this article is strictly for educational purposes and is not meant to replace the professional knowledge or advice of your personal dentist.)