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June 20, 2003 -- Less may be more when it comes to brushing your teeth. A new study shows that applying more than a light amount of pressure to your teeth or brushing longer than two minutes doesn't make them any cleaner and may increase the risk of oral health problems.
Experts say many people believe that the longer and harder you brush your teeth, the better it is for your teeth. But the study shows there's a limit to the amount of pressure your teeth can take, and beyond that extra force or time doesn't do any further good.
Researcher Peter Heaseman, professor of periodontology at the Newcastle University's School of Dental Sciences, says the goal of brushing your teeth is to remove plaque, the sticky substance that can harden on teeth and gums when bits of food are left in the mouth. Plaque buildup can cause problems beyond just cavities, such as gum disease. But brushing too hard or for too long can damage the protective enamel on your teeth or irritate your gums and cause other oral health problems.
Researchers studied the brushing techniques and times of 12 volunteers who used electric toothbrushes during a four-week study. The participants were taught how to use the oscillating toothbrush, which was hooked up to a computer that took time and pressure measurements. Researchers compared 16 combinations of various brushing times and pressures. Plaque levels on the teeth were also recorded before and after brushing.
They found that plaque removal improved with longer brushing time up to two minutes and with greater pressure up to 150 grams of pressure, which is about the weight of an orange.
"Although we found that you have to brush your teeth reasonably long and hard to get rid of the harmful plaque which causes dental diseases, our research shows that once you go beyond a certain point, you aren't being any more effective," says Heaseman, in a news release. "You could be actually harming your teeth and gums."
Heaseman says the same results would also be expected if the volunteers had used ordinary toothbrushes rather than the electronic versions.
Researchers say the force necessary to brush your teeth is actually quite light because the pressure is being applied to a very small area.
"If you are unsure how to go about brushing your teeth, the best thing to do is to make an appointment with your dentist or dental hygienist who will be able to train you in the correct techniques and will show you approximately how much pressure you should be applying," says Heaseman.
SOURCES: Journal of Clinical Periodontology, vol. 30, 2003. New release, University of Newcastle upon Tyne, UK.