In addition to satisfying these conditions, powered or electric toothbrushes bearing the seal also must undergo safety testing in an independent lab and prove through clinical trials that the toothbrush is safe for use on the tissues of the mouth and teeth, as well as any dental hardware that may be in place.

For disposable toothbrushes, this seal ensures that: the bristles will have safe tips; the bristles will not fall out of the toothbrush under typical brushing conditions; the handle will withstand normal use; and the toothbrush will effectively reduce plaque build-up and gum disease in their early stages.

Toothbrushes: Disposable or Electric?

As long as you clean your teeth regularly using proper brushing technique, you should be able to reduce plaque build-up and keep your gums healthy with either a manual or powered toothbrush. Here are some things to keep in mind as you go about choosing the best toothbrush:

Cost. Although there are some more affordable powered toothbrush options being sold, electric toothbrushes cost many times more than manual toothbrushes. In addition to the initial expense of an electric toothbrush, you will need to replace the removable toothbrush head as often as you replace your manual toothbrush. Of course, if using an electric toothbrush helps you keep your teeth cleaner, you may make up for the expense with a reduction in dental bills.

Likability. When it comes down to it, the best toothbrush for you is going to be the one you're most likely to use -- and use well. Some people may not like the vibrating feeling of a powered toothbrush. Others might find an electric variety easier to use to clean all tooth surfaces. This may be especially true for people with conditions that limit mobility, such as painful arthritis. If you enjoy using your toothbrush, you're more likely to brush for the recommended length of time -- two minutes. Some powered varieties even have a built-in timer to let you know when you've devoted enough time to brushing.

Effectiveness. Numerous scientific studies have been conducted to investigate whether manual or powered toothbrushes are more effective at reducing gum disease and eliminating plaque. A review of nearly 30 studies comparing disposable and electric toothbrushes found that, overall, there was not a significant difference between electric and manual toothbrushes in their ability to remove plaque and prevent gum disease. But, evidence suggests that a certain type of powered toothbrush called a rotation oscillation toothbrush (the bristles go round and round and back and forth) is more effective than manual toothbrushes.

Safety. Although all toothbrushes with an ADA Seal of Approval have been tested for safety, there may be certain individuals for whom a particular type of toothbrush is safer. If you tend to brush too vigorously, which can damage your gums and teeth, a powered toothbrush may make it easier for you to be gentle on your gums and teeth and get them clean at the same time. Some studies suggest that using a powered toothbrush may increase the amount of bacteria in the bloodstream more than a manual toothbrush. This does not pose a risk for healthy people with normal immune systems and healthy hearts. But it could increase the likelihood that people with certain heart conditions could acquire a potentially dangerous infection in the heart. Further investigation is needed to determine whether this should be a cause for concern.