From the time we're young, we're taught that using a toothbrush regularly is one of the best ways to keep our teeth and gums healthy. But which toothbrush is best?

In the late 1930s, when toothbrushes with nylon bristles were first invented, consumers choosing a toothbrush didn't have many options. Now, the story's completely different when it comes to toothbrushes. Most stores that sell oral hygiene products now have an extensive collection of different types of toothbrushes on their shelves, including manual (disposable) and powered (electric) varieties.

There are certain characteristics that you should look for in whatever toothbrush you choose, regardless of whether it is manual or powered.

Size. The best toothbrush head for you should allow you easy access to all surfaces of your teeth. For most adults, a toothbrush head a half-inch wide and one-inch tall will be the easiest to use and the most effective. Though there are larger toothbrush heads available, you may find that it is difficult to maneuver them to clean certain hard-to-reach areas, such as the sides and backs of your molars. The toothbrush should have a long enough handle so you can comfortably hold it in your hand.

Bristle variety. If you go to the drug store to purchase a manual toothbrush or a replacement head for your electric toothbrush, you will be able to select a toothbrush with soft, medium, or hard nylon bristles. For the vast majority of people, a soft-bristled toothbrush will be the most comfortable and safest choice. Depending on how vigorously you brush your teeth and the strength of your teeth, medium- and hard-bristled brushes could actually damage your protective tooth enamel. For even more tooth protection when you brush, be sure the bristles on the toothbrush you select have rounded tips.

Expert recommendation. To ensure your toothbrush has undergone rigorous quality control tests for cleaning effectiveness and safety, ask your dentist for a recommendation. Or look for manual or powered toothbrushes that have earned the American Dental Association Seal of Approval.

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 its early stages.

In addition to satisfying these conditions, powered or electric toothbrushes bearing the seal also must undergo safety testing in an independent laboratory and prove through a clinical trial 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.

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 every three or four months. 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.

When it comes to choosing the best toothbrush for your child, it's important to opt for one that your child will use properly and regularly. There are a variety of disposable and electric options available for children. And they come in a variety of colors and often feature children's favorite characters from classic stories and popular cartoons. Some varieties even play music to help your child know how long to brush.

To choose a good toothbrush for your child, try the following suggestions:

• Make sure the toothbrush you select has an ADA Seal of Approval.
• Pick a child-sized toothbrush with soft bristles.
• If your children are old enough, have them help you pick out their toothbrushes. Getting your children involved in the process and excited about a new toothbrush may make tooth-brushing a more enjoyable task.