Aggressive tooth brushing removes the outer portion of the teeth, which is called "enamel." It can also remove the thin layer that's situated behind enamel, which is called "dentin." At times, people brush with a "heavy hand," and at other times, people choose toothbrushes that have hard bristles. Both of these practices can cause a lot of problems for the mouth. We can help restore your dental health, but it's better to avoid problems in the first place.