Since the 1950s, the American Heart Association (AHA) has urged a sizable group of people to take antibiotics before having dental work or other procedures that might flood the bloodstream with bacteria.
The antibiotics were supposed to prevent infective endocarditis, a potentially serious infection of the heart's lining. After a look at the latest evidence, the AHA now emphasizes routine oral care and recommends pre-procedure antibiotics for only some people.
Infective endocarditis occurs when bacteria invade the innermost layer of the heart's chambers. It isn't common, but it is hard to get rid of and potentially deadly. It can make heart tissue prone to other infections, damage heart valves, and lead to heart failure, stroke, or heart rhythm problems.
Even so, no large trials have tested whether taking antibiotics before dental work actually prevents endocarditis. If antibiotics do help, the effect is so small that the risk of side effects from the medication outweighs the benefits for most people, explains the Harvard Heart Letter.
The AHA now says you need antibiotics before dental procedures only if you have an artificial heart valve, you've had endocarditis before, or you've had a heart transplant and developed a valve problem. Some people who were born with heart problems may also need antibiotics depending on whether and how the defects were repaired.