Enamel is the hard, outer layer of your teeth. It is fairly transluscent with a high gloss.
Enamel is the hardest substance in the body and scores a 5 on the 1-10 Mohs Hardness Scale:
Mohs Hardness Scale
MINERAL COMMON EXAMPLE
1 Talc Pencil lead 1.0-2.0
2 Gypsum Fingernail 2.5
3 Calcite Copper penny 3.5, brass
4 Fluorite Iron
5 Apatite Tooth enamel, knife blade, glass 5.5-6.0
6 Orthoclase Steel file 6.5
7 Quartz Scratches glass
8 Topaz ——
9Corundum Saphire, ruby
10 Diamond Synthetic diamond
In dentistry, enamel is important to bonding fillings and crowns onto teeth because bonding agents bond much better to enamel than they do to dentin. Often, when placing a filling on a front tooth, I place a bevel around the edge of the filling to increase the surface area of the bond.
Here is a photo of a bevel:
The small rainbow-shaped reflection on the lower right corner of the upper middle tooth is the bevel I cut into the tooth.
Enamel on baby teeth begins to form by a process called amelogenesis during the third month of fetal development and is completed around one year of age. Enamel develops from the tips of the teeth toward the roots, laying down one layer each day corresponding to the Circadian rhythm.
In my practice, I often describe enamel to patients as similar to a brick wall. The wall is made up of minerals such as Calcium, Phosphates, and Fluoride. When acid (plaque) sits on enamel, it removes minerals/bricks. This is called demineralization. When enough bricks are missing, a hole is visible either in x-rays or upon clinical examination. That is a cavity. Mineral “bricks” start to leave the enamel surface in an acid that measures 5.5 or smaller on the pH scale. Examples of pH in acidic fluids:
Water 7.0 (remember, anything over 5.5 is ok)
Diet Coke 3.39
Diet Pepsi 3.05
Hawaiian Fruit Punch 2.82
Coke Classic 2.53
Battery Acid 1.00
Fluoride is a naturally-occurring substance that happens to fit into the space of missing bricks and leaves the enamel stronger than it is without it.
Dental materials manufacturers continue to create products that mimic enamel in every way: hardness, wearability, how it wears opposing teeth, flexibility, and translucency. Dental filling material is often layered to achieve the best esthetic outcome possible.
Here is an example of enamel replaced with porcelain in my office: