Antibiotics for Prevention of Endocarditis during Dentistry: Time To Scale Back?

Antibiotics should be given to prevent endocarditis when a predisposed patient undergoes dental treatment. This 50-year-old doctrine is based on a logical premise: Dental procedures induce bacteremias with bacterial species that often cause endocarditis, and endocarditis carries high morbidity and mortality; therefore, antibiotics should be administered to susceptible patients before dental procedures to prevent endocarditis [1]. Furthermore, antibiotics definitely can prevent endocarditis in experimental animals [1-3]. On these grounds, prophylaxis against endocarditis is widely recommended [1, 4]. Although compliance has been less than perfect [5] and apparent failures of prophylaxis are not rare [6], the practice is now so entrenched that failure to give prophylaxis has generated many malpractice claims [7]. However, its effectiveness in humans, let alone its cost-effectiveness, has not been proven and probably never will be [1].

The foundation for the practice of endocarditis prevention has been questioned repeatedly [8-14] but not seriously shaken. As a colleague wryly commented, “The less the evidence there is, the more antibiotic we give.” Now, Strom and colleagues [15] have stirred the pot with a major case–control study of 273 adults in which no link was found between endocarditis and dental procedures. The incubation period before onset of symptoms when endocarditis follows a dental procedure is usually short [16], but in this study, the calculated risk for endocarditis was no higher in the first month after dental treatment than after 2 or 3 months. This finding is consistent with a lack of a link between the two events. Of course, it does not prove that dental procedures never cause endocarditis-occasionally, they do [17, 18]. The authors simply argue that this happens too rarely to justify routine use of antibiotic prophylaxis. This supports the …