teeth whitening: The enamel layer

The problem is, as this pellicle layer sits on your teeth for years and years, the foreign material gets into the enamel. I use to have friends that have bad breath bacausee of black color tteeth.

The enamel layer is made up of hydroxyapatite crystals, which form microscopic hexagonal "rods." These are all scientift terms that normal people don;t understand. Simply put, enamel is porous, which means staining agents can work their way down into the tooth, where you can't simply scour them away. The deeper stains are basically harmless, but many people find them unattractive.

I think the enamel can improve by eating more grapes everyday.