Toothbrushes: Are the electric ones better than ordinary manual brushes?

Whether or not electric toothbrushes clean teeth better than manual toothbrushes depends on the way the head moves. Rotation oscillation brushes that move in one direction and then the other remove plaque a bit better than ordinary toothbrushes.

Brushing teeth is an effective way to prevent tooth decay (dental caries or cavities), if fluoride toothpaste is used. Fluoride strengthens the tooth against decay. You can read more about fluoride here. Toothbrushing removes plaque.

Plaque builds up at the edges of the gums in particular. Many experts suggest that the bacteria growing in plaque can cause cavities and gingivitis (gum inflammation). The signs of gum inflammation are bleeding, although this usually does not have serious consequences.

Sometimes, though, this inflammation can lead to a gum infection that goes down into the bones under the teeth. This condition is called periodontitis. That stage of the disease can cause teeth to loosen and fall out.

It is open to question whether or not particular toothbrushes can prevent more serious problems than plaque and gingivitis. A great range of toothbrushes are on the market. There is a lot of competition between different models of electric toothbrushes. One essential difference between them is the motion of the brush heads. With some the head moves from side to side like windscreen wipers, and in others the head rotates. Some brushes vary the direction of the rotation, with the head changing direction of its rotations several times a second. This motion is called rotation oscillation.

In order to answer the question of whether any type of toothbrush cleans teeth better, researchers from the Cochrane Collaboration systematically reviewed trials. Their search found 42 trials involving about 3,900 people, which tested seven types of electric toothbrushes. Most of the trials were funded by the manufacturers of the electric toothbrushes, who clearly had an interest in showing that their products did better.

However that was not always the case. The Cochrane researchers concluded from their analysis that most electric toothbrushes do not do much better than ordinary toothbrushes. Rotation oscillation brushes removed plaque somewhat better than manual toothbrushes. There was also less gum bleeding when this type of toothbrush was used for more than three months.

The differences were so small though, that it was first noticeable when larger groups were looked at. One way of measuring gum bleeding, for example, involved using an instrument to press on the gums of the people in the trials to count how often this led to bleeding. In these trials, about 40 out of every 100 spots tested bled at the beginning of the trial.

After three months of brushing, the number of places that bled dropped to 24 out of 100 in the people who were using ordinary toothbrushes. For the people using rotation oscillation brushes, the number dropped to around 20 out of 100.

These numbers show that people who do not have a problem with bleeding gums would probably hardly notice any difference if they changed to the substantially more expensive kind of toothbrush. But it is still unclear whether or not brushing teeth with electric toothbrushes also reduces tooth decay or more serious gum disease.

There is little information about possible side effects of using electric toothbrushes. Damage to the gums or teeth from electric toothbrushing were unusual in the trials.