Q. I've been brushing with a manual toothbrush my entire life. But my best friend insists that electric toothbrushes are better. Should I switch?
A. What matters most is that you brush your teeth at least twice a day. That's the way you keep plaque from forming. Plaque is a sticky film that attaches to the surface of your teeth. If it isn't removed, it can lead to tooth decay and gum disease. Brushing regularly keeps plaque in check.
Certain bacteria that live in the mouth mix with saliva to cause plaque. In particular, a kind of bacteria called "Streptococcus mutans" -- a distant cousin to the bacteria that cause strep throat -- is the bad guy.
Some of my patients are surprised to learn that bacteria live in their mouths. Boy, do they. There are more bacteria living in your mouth than there are human beings on planet Earth. And that's just your mouth! There are more than 7 billion of them in everyone's mouth -- and trillions of them in the gut below the mouth.
But I digress. You asked whether electric toothbrushes are any better than the tried-and-true manual brushes.
My colleague Dr. Hans-Peter Weber of Harvard Dental School explains that most electric toothbrushes are no better than regular toothbrushes when it comes to removing plaque, maintaining gum health or removing stains.
He says there is one exception, however. One type of electric brush -- the rotation oscillation design (where the brush heads rotate in one direction and then the other) -- is better at removing plaque and reducing gum inflammation than a manual toothbrush. Examples of this design include brushes in the Braun Oral-B Triumph and ProfessionalCare lines.
Even if many electric toothbrushes are no better than manual toothbrushes at removing plaque, they may have other advantages for some people. An electric toothbrush can be particularly helpful for people who have trouble reaching all corners of their mouths.
Power brushes are also useful for parents brushing their young children's teeth and for people with mental or physical disabilities that impair dexterity. The thicker handle on power models is also a plus for older people and those with arthritis who have difficulty grasping the thinner shaft of a manual brush.
Ultimately the best brush is simply the one you feel most comfortable with.
We have more information on dental health in our Special Health Report, "Dental Health for Adults: A Guide to Protecting Your Teeth and Gums." You can find out more about it at my website.
No matter what type of brush you choose, replace your toothbrush when the bristles splay out of line. And remember, on any toothbrush, softer bristles are better. Finally, brush your teeth at least twice a day -- once after you eat breakfast and again before you go to sleep.
• Dr. Komaroff is a physician and professor at Harvard Medical School. Go to his website to send questions and get additional information: AskDoctorK.com.