Re: Question for you, StratRebel

Ok, think of a building. You have the metal beam scaffold that holds the shape and structure of the building. And then you have the walls and everything else that goes inside the scaffold.

When the building gets damaged, you may lose walls and furniture, but as long as that metal scaffold stays up, things are fairly easy to fix. However, if one of those metal beams gets damaged or destroyed, you basically have to start from scratch.

The tooth is the same way. The enamel matrix is like the metal scaffold of a building, it holds the shape of the tooth. Inside that matrix is the minerals that make the surface hard (like the walls, drywall, insulation, etc of a building), these would be calcium, phosphate, fluoride, hydroxyappetite, etc.

Just like a building thats damaged, a tooth can loss small parts without permanent damage. Bacteria create acid that leeches out the minerals from the tooth, but the matrix will still be intact as long as you keep enough minerals inside. This process is called demineralization. If you remove the bacteria, restore the pH, the body can come back and replace those minerals and restore the tooth to normal. This is called remineralization.
However, when you lose enough minerals, the enamel matrix can no longer hold its shape and it collapses, creating a hole (or cavity). Nothing the body does can replace this matrix, so the damage is permanent. This is what I meant by saying enamel cannot "regrow", because you cannot create new matrix once the tooth erupts.

In your case, you have lost the matrix. You can tell this because the enamel has become thin enough to show the yellow dentin below. Now, as long as you keep it clean, the likelihood it becomes and actual cavity is small. The only long term problem you might have with a spot like that is increased sensitivity to cold/heat. The enamel and dentin act like insulators for your tooth nerve, the thinner they get, the less they can insulate.

If its not sensitive, I would not worry much about it, just keep it clean. If you are sensitive there are several options to help.

Does this analogy help?