Which antibiotic prophylaxis guidelines for infective endocarditis should Canadian dentists follow?

D ental providers must keep up to date with antibiotic prophylaxis guidelines for infectious endocarditis (IE) as these guidelines represent standards of care and determine medicolegal standards. A survey of Canadian dentists revealed that practitioners tend to employ antibiotic prophylaxis according to the guidelines in place at the time of their graduation from dental school — guidelines that often do not meet the current standards, 1 as both the American Heart Association (AHA) 2 and the British Society for Antimicrobial Chemotherapy (BSAC) 3 have currently updated their recommendations. Host factors that increase the risk of IE include specific cardiac abnormalities, a previous episode of IE and the extent of the dental procedure to be undertaken (Table 1). In the 2007 revision of its recommendations, the AHA limited the conditions for which endocarditis prophylaxis is recommended before dental treatment to those associated with the highest risk (Table 2). It is important to note that valvular disease independent of re-gurgitation is not a condition for which the AHA recommends prophylaxis. 2 This will result in considerable reduction in the use of IE antibacterial prophylaxis. It is believed that invasive dental procedures associated with bleeding increase the risk of oral bacteria entering the blood circulation. Although there is evidence that the risk of infection due to treatment-related bacteremia may occur during a short window of less than 2 weeks following a procedure, dental procedures conducted even months earlier may be questioned as causative of IE. 4 Furthermore, periodontal and dental disease increase the risk of bacteremia with activities of daily living and may more commonly cause bac-teremia; therefore, good oral care is of paramount importance in patients with conditions that place them at risk for IE. To reduce the risk of IE following dental procedures, prophylactic measures have been developed by experts in the fields of microbiology, epidemiology, cardiology and dentistry. The principle preventive measure recommended is the use of prophylactic antibiotics before certain dental procedures in patients identified as at risk. The first AHA-recommended prophylaxis regimen was issued in 1955; the most current recommendations were issued in 2007. 2 The British Cardiac Society 5 and the BSAC 3 have also recently updated their recommendations for IE prophylaxis (in 2004 and 2006, respectively). This article provides a summary of those guidelines and notes the differences among them. The continuing evolution of IE prophylaxis guidelines has recognized the natural history of the condition, risk …