Cavity Basics

What is a cavity/tooth decay?

A cavity is an open pathway in the tooth which is caused by bacterial invasion.  In the dental world, it’s referred to as a carious lesion.  The severity of the cavity/carious lesion will determine which type of restoration is needed.

How would I know if I have a cavity?

If you experience pain in the tooth, more than likely it can be attributed to bacterial invasion/cavity.  However, keep in mind that tooth pain can be attributed to several other factors such as periodontal disease.  The best way to tell if you have a cavity is to visit the dentist.  Sometimes, cavities occur between our teeth, and the only way to determine its presence is on a radiograph/x-ray. 

What can be done to prevent cavities?

Brush, brush, and brush some more!!  If you brush 3 times a day, or even better, after each meal, you will remove food debris and other agents that act as magnets for bacteria.  If you are unable to brush that often, be sure to chew gum with Xylitol after your meals.  This will aid in remineralizing your enamel after a meal, thus making it stronger and more resistant to bacterial invasion.  Please see our article on gum with xylitol for more information.

Please see our article on cavity prevention for more information on maintaining a healthy mouth.

Tooth Anatomy

The tooth is composed of 4 layers, the enamel, dentin, cementum, and dental pulp.

What is enamel?

Enamel is the hardest substance in the entire body.  It’s the outside layer of the tooth, completely covers the dentin, and is actually transparent in color.  That means the color of our teeth is due to dentin and not enamel.  However, enamel is comprised of enamel rods which can hold stain quite easily, including red wine, coffee, tea, and cigarettes.

What is enamel comprised of?

Enamel is comprised of 96% calcium hydroxyapatite and 4% organic material and water.  Bone is composed of 50% hydroxyapatite and 50% organic material including collagen, thus making enamel the hardest substance in the body.

If I chip or break enamel, will it repair on its own?

Unfortunatley, enamel does not contain any living cells.  Therefore, if chipped, it will not repair itself.  However, dentin can repair itself if damaged.

What is hydroxyapatite?

Hydroxyapatite is a storage form of calcium in the body.  99% of calcium in bone is stored as hydroxyapatite.  The chemical formula for hydroxyapatite is Ca₅(PO₄)₃OH.

What is dentin?

Dentin makes up the bulk of the tooth.  It completely surrounds the pulp, and is covered by enamel on the crown portion of the tooth, and by cementum on the root of the tooth.  Dentin is usually yellow in color and ultimately determines the color of the tooth, being that enamel is transparent.  Dentin is composed of dentinal tubules that communicate directly with the pulp.  This means that is bacteria reaches the dentin, usually some type of pain will be felt.  Dentin is composed of 65-70% calcium hydroxyapatite, 20-25% organic material, and 10% water.

What is cementum?

Cementum covers dentin on the root surface of the tooth.  Cementum connects the tooth to the periodontal ligaments and is therefore somewhat responsible for securing the tooth in the bone.  It is composed of 50% calcium hydroxyapatite and 50% organic material and water, the same consistency as bone.

What is pulp?

Pulp is the livelihood of the tooth.  Pulp supplies nutrients, blood, and nerves to the tooth.  This means that the pulp is responsible for keeping the dentin, cementum, and dentin strong.

Well what if my pulp is removed with a root canal?

Once bacteria reaches the pulp, depending on how extensive, it’s usually recommended to have the pulp removed.  This is because the pulp communicates directly with the rest of the body, and if harmful bacteria is present in your pulp, and it easily move to other areas of the body, including the brain!!  Please see the article on root canal for further information on this subject.

Child Tooth Basics

These teeth are similar to our adult teeth except smaller (of course!!!).  Also, children don’t have as many teeth as adults.  Where adults have 32 teeth, children only have 20.  The descriptions listed below can also be found on the adult page.

Incisors:

These are the main teeth that are visible when we smile.  Children have four on top and four on the bottom.  They are used primarily for “incising” or cutting into food.  The two in the middle are known as the central incisors.  The outer two are referred to as the lateral incisors.

Canines:

Believe it or not, these are the longest teeth in the mouth (root included).  Located next to the lateral incisors, these teeth are the cornerstones of the mouth.  Canines are used for tearing or shearing food.  They are sharp and usually form a point at the tip.  Children have four canines, two on the top and two on the bottom.

Premolars:

Children do not have premolar teeth.  These teeth are only found in the adult dentition.

Molars:

Molars are the largest teeth in the mouth.  Children have 8 molars, 2 on each side on the top and bottom.  These teeth are used for chewing food.

Adult Tooth Basics

We have 2 sets of teeth in our lifetime.  A childhood set, known as the deciduous or primary dentition, in which we normally begin to lose around the age of 6.  The adult set, also known as the permanent or succedaneous set, is what we keep for the remainder of our lives, that is if we keep our mouths in good condition.  Naturally, the adult mouth contains 32 teeth separated into 4 separate categories: Incisors, Canines, Premolars, and Molars.  So what is in your mouth and how do you know what is what?

Incisors:

These are the main teeth that are visible when we smile.  We have four on top and four on the bottom.  They are used primarily for “incising” or cutting into food.  The two in the middle are known as the central incisors.  The outer two are referred to as the lateral incisors.

Canines:

Believe it or not, these are the longest teeth in the mouth (root included).  Located next to the lateral incisors, these teeth are the cornerstones of the mouth.  Canines are used for tearing or shearing food.  They are sharp and usually form a point at the tip.  Adults have four canines, two on the top and two on the bottom.

Premolars:

Premolars, also known as cuspids, are located between the molars and the canines.  We have 8 premolars in the mouth, a first and second premolar.  The first premolar may somewhat resemble the canine in that it may appear somewhat sharp and form a point at the tip.  These are used for grinding and chewing food.

Molars:

Molars are the largest teeth in the mouth.  We have 12 molars, 3 on each side on the top and bottom.  These teeth are used for chewing food.