Reprinted from the American Academy of Periodontology website.
Selecting a toothbrush: Look for a toothbrush that has the ADA Seal of Acceptance and soft-bristles. The size and shape of the brush should fit your mouth.
Step-by-Step: To clean the outside surfaces of your teeth, position the brush at a 45-degree angle where your gums and teeth meet. Gently move the brush in a circular motion several times using short, gentle strokes. Apply light pressure to get the bristles between the teeth. This should not cause discomfort. Use the same method on the inside of the back teeth. Move the brush in short, gentle but firm strokes, keeping it angled against the gumline.
To clean the inside surfaces of the upper and lower front teeth, hold the brush vertically. Make several gentle back-and-forth strokes over each tooth and its surrounding gum tissue.
To clean the biting surfaces of your teeth, use short gentle strokes. Since the toothbrush can clean only one or two teeth at a time, change the position of the brush as often as necessary to reach and clean all tooth surfaces. If you have any questions, ask your periodontist or dental care provider.
Don't forget to floss. There's no clear answer on whether it's better to floss first then brush or brush then floss. Flossing first may loosen plaque, which can then be brushed away with your toothbrush.
Don't skip the professional visits. Professional cleanings at least twice a year are necessary to remove calculus from places your toothbrush and floss may have missed. And, a professional evaluation can determine if you have periodontal diseases.