EMBARGOED FOR RELEASE: 14 NOVEMBER 1998 AT 17:00:00 ET USContact: Rebecca Harmon
harmonr@mail.med.upenn.edu
215-349-5660
University of Pennsylvania Medical CenterPenn Scientists Find No Link Between Dental Procedures And Heart Valve Infection
Philadelphia, PA -- For the past 40 years, anecdotal information has suggested a link between dental procedures and the onset of endocarditis, a potentially deadly inflammation of the heart's lining and/or valves caused by bacterial infection. As a result, professional guidelines issued jointly by the American Heart Association (AHA) and the American Dental Association (ADA) have recommended the administration of prophylactic antibiotics to dental patients deemed at-risk for the development of endocarditis -- i.e., those with known heart valvular problems, including mitral valve prolapse and heart murmurs.
Today, however, researchers at the University of Pennsylvania School of Medicine have determined that dental procedures are not a risk factor for endocarditis, even in patients with underlying cardiac valvular abnormalities (who, the researchers confirmed, are at increased risk for endocarditis). The researchers' study appears in tomorrow's Annals of Internal Medicine.
As a result of their findings, the researchers recommend a reconsideration of current policies for antibiotic prophylaxis of persons with cardiac valvular abnormalities who are about to undergo dental treatment. "Only a few cases of infective endocarditis could be prevented by prophylactic antibiotics for dental procedures, even if 100% effectiveness were assumed," said Brian L. Strom, MD, MPH, lead author of the study and Chair of the Department of Epidemiology and Biostatistics at Penn. "Given the failures of prophylaxis which occur even with recommended antibiotic regimens, the low incidence of the disease, and the rare, but real, risk of adverse reactions to the antibiotics, we conclude that current policies should be reconsidered." Still another factor for reconsideration, adds Strom, is that antibiotic-resistance is increasing in the general population as a result, in part, of the overuse and misuse of antibiotics.
If fall-out bacteria from dental work is not a major culprit in the development of endocarditis, then what is? According to Strom, "transient bacteremia is documented as part of everyday life -- coincidental with tooth brushing, chewing food, and after tooth brushing."
To reach their findings, the scientists compared the relationships between previous dental work performed on 273 "case patients" (those diagnosed with infective endocarditis that was not associated with intravenous drug use) and previous dental work performed on 273 "controls" (community residents with no endocarditis, and who were matched with the former group according to age, sex, and neighbornood of residence). The case-patients were derived from 54 participating hospitals throughout the Delaware Valley Area. Phone interviews with study subjects, supplemented by medical and dental records, then determined the exact nature and timing of individuals' previous dental work.
The results showed that neither dental work, in general, nor any individual dental procedure was significantly associated with infective endocarditis -- except, possibly, tooth extraction. In particular, among case-patients and controls with known cardiac abnormalities -- the target of antibiotic prophylaxis -- the risk for infective endocarditis was not increased by dental treatment.
"As a result of our findings, we believe that if any associations exist, too few cases result to justify the expense and risk of widespread prophylactic antibiotic use," notes Strom.
The research was supported by a grant from the National Heart, Lung and Blood Institute of the National Institutes of Health (NIH).
Editor's Note: Dr. Brian Strom can be reached directly at (215) 898-2368.
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