Most dentists don’t go a day without seeing patients who are damaging their teeth and gums by brushing too hard. Some report that as many as two out of three patients brush their teeth too hard. This is a problem. A stiff-bristled toothbrush combined with overzealous brushing teeth can cause serious dental problems over time, including gum disease and tooth sensitivity.
People think that if they brush twice as hard, they will do twice as much good, In fact, overzealous brushing can cause significant damage to the periodontal tissues and bones that support the teeth. If you used the same amount of force and brush the side of your arm, you could take your skin off.
One way to avoid damaging your teeth and gums is to purchase a "soft" toothbrush featuring rounded bristles which are less abrasive to teeth. You should hold the brush between the thumb and forefinger, not with the fist. When brushing, do not `scrub' the teeth with a horizontal, back-and-forth motion. Instead, start at the gum line and angle the brush at a 45-degree angle. Brush both the teeth and the gums at the same time. Push hard enough to get the bristles under the gumline but not so hard that the bristles flare out. It's also a wise move to limit the amount of toothpaste because it is abrasive.
The irony is that dentists want people to brush longer, not harder. Children and adults tend to spend less than one minute at a time brushing their teeth, even though removing plaque from the mouth requires at least two to five minutes of brushing at least twice a day. Remember: brush longer, not harder.