What is a Dental Cavity

A cavity or dental caries is nothing more than a hole that has formed in the tooth by dissolving an area of the outer layer: enamel.  Enamel is the second hardest compound on earth, second only to diamonds.  A cavity can form when three things are present: a tooth, food and bacteria.

Firstly, a tooth must be present for a cavity to form.  I promise I am not trying to sound silly, but babies could have the bacteria and eat food, and not get cavities because there is not a tooth for the bacteria to attach.

Secondly, food must be present for cavities to form.  Certain foods can lead to cavities more frequently than others.  Foods that are high in processed sugars, such as candies, starches, and fruit juices, are more easily processed by the bacteria that live in our mouths.  Foods that are less likely to create cavities are things such as cheese, nuts, and apples. 

Thirdly, bacteria or “sugar bugs” as I call them, must be present for a cavity to form.  The mean sugar bug’s name is Streptococcus mutansS. mutans can adhere to teeth and if left to his own devices, can produce an acidic byproduct that can breakdown the protective enamel exposing the softer dentin below.  S. mutans loves starchy foods because it is easier for them to breakdown.  And guess what its byproduct is.  That’s right!  Acid.  S. mutans has an interesting quality in that it thrives in an acidic environment and every time we eat or take a sip of a beverage other than water; the oral cavity becomes acidic.  Now, it’s okay!  Our saliva attempts to counterbalance the acidic environment and bring the mouth back to neutral.

But, when food and plaque sit on teeth, the environment underneath the plaque is acidic, it can stay stuck to the enamel until we remove it from the teeth with a toothbrush or floss.  In the acidic environment, the minerals that make enamel so strong, can get broken down and is unable to recover.  At that time, a cavity will form. 

The last thing needed to form a cavity is time.  It takes time for the acid to break through the enamel and reach the underlying layer of dentin.  Can I give you some bonus information?  Did I hear you yell an emphatic “YES”?  I’m so glad you did.  Research studies show that it takes approximately six months for a cavity to break through the enamel layer.  It is for this reason that insurance companies cover a cleaning every six months and one day.  And not a moment sooner!