Tooth enamel is the hardest and strongest substance in your body, playing a vital role in protecting your teeth. It coats the outer layer of your teeth to form a barrier that safeguards the inner layers, including dentin, from the effects of destructive bacteria. Enamel also protects your teeth as you chew and bite food, and provides insulation against tooth sensitivity when you eat hot or cold foods.However, enamel is still susceptible to decay, and can be broken down by a build-up of tartar around the gum line and on the teeth. Unfortunately, enamel cannot regenerate because it has no living cells. This is why it’s crucial to brush and floss your teeth at least twice each day to get rid of bacteria-producing substances like acids, sugars and starches.