Enamel Decay
Tooth decay is a process that occurs gradually over time. It ordinarily begins at the outer layer of enamel where plaque has formed. Because enamel is almost entirely made up of minerals and has no live cells or nerves, this stage is usually painless and often goes unnoticed.

Dentin Decay
The decay then penetrates the dentin . The dentin is made up of both minerals and living cells. These cells are connected to the nerve cells in the pulp. A person may begin to notice increased sensitivity or even some pain, although this stage can also go unnoticed.

Since decay spreads faster in the dentin, the softer tissue becomes affected and cannot support the enamel. At this stage, the tooth may break and cavities can form.

Pulp Decay and Pulp Death
Next the pulp (the center tissue of the tooth) becomes inflamed. Left untreated, the decay will reach into the pulp, which contains pain sensitive nerve endings. The tooth will most likely ache. This requires dental assistance or the tooth may die.

Formation of an Abscess
Infection causing bacteria forms an abscess, which can spread bacteria to adjoining teeth or other parts of the body. Caught early enough, the tooth can usually be saved by a root canal procedure, usually followed by a crown. If the tooth cannot be saved, it will have to be extracted.

Because the early stages of tooth decay are relatively painless and often go unnoticed, it is extremely important that you schedule an appointment with your dentist every six months for a checkup and cleaning.