Tooth Decay Prevention

So What is tooth decay?

Tooth decay is a disease process where acidic waste products created by oral bacteria cause damage to the hard (mineralized) tissues of a tooth (enamel, dentin and cementum). If left unchecked, a point can be reached where enough mineral content is finally lost that a defect (a hole or a "cavity") forms on the tooth's surface.

Tooth Anatomy - The mineralized tissues of a tooth.

In order to understand tooth decay you first need to think of a tooth as being a hard, calcified object. Yes, teeth do have "nerves" (pulp tissue) in their center and this tissue is soft. But the surface of a tooth (where the tooth decay process begins) is made out of dental tissues that have a very high mineral content.

The mineralized tissues of a tooth are enamel, dentin and cementum. (The mock-up of a dental x-ray shown to the right illustrates where the dentin and enamel portions of a tooth are located. Cementum is a very thin covering that lies on the surface of a tooth's root.)

Tooth Enamel
Most of a tooth's visible surface (and quite possibly even 100% of what you see) is covered by enamel. You've probably heard that tooth enamel is the hardest tissue found in the human body. This is true. Enamel is more than 95% mineral in composition. Most of this mineral content is a compound very rich in calcium called hydroxyapatite.

Dentin
You may be surprised to learn that teeth are not solid enamel. Only the surface layer of a tooth's "crown" (that portion of a tooth that nature intended to lie at and above the gum line) is enamel. The bulk of a tooth, both its root and inner aspects, is composed of another calcified tissue called dentin. Dentin also contains the mineral hydroxyapatite, but to a lesser degree than enamel. Only about two thirds of the composition of dentin is mineral so, relatively speaking, dentin is "softer" than enamel.

Cementum
Cementum is a thin calcified layer that lies on the surface of a tooth's root