In 2007 the American Heart Association changed the guidelines so that only people at highest risk for developing infective endocarditis are now advised to receive prophylactic antibiotics before invasive procedures.

CNN: Why do I no longer need an antibiotic before teeth cleaning?

For certain heart conditions, antibiotics are recommended about one hour before invasive medical procedures to prevent a condition called infective endocarditis, which is a potentially life-threatening bacterial infection of the inner lining or valve within the heart.

CNN: Why do I no longer need an antibiotic before teeth cleaning?

The changes were made because it was discovered that infective endocarditis is more likely to occur after frequent exposure to bacteria from routine activities such as chewing food or brushing one's teeth than from occasional dental, gastrointestinal tract or genitourinary tract procedures.

CNN: Why do I no longer need an antibiotic before teeth cleaning?