A critical appraisal of antibiotic prophylaxis.

To some, antibiotic prophylaxis has reached the level of doctrine: it is highly successful with little attendant harm to the patient. To its skeptics, antibiotic prophylaxis has rarely been proved effective in human clinical studies and possesses little present scientific justification. The truth lies somewhere between the two extremes. The use of antibiotic chemoprophylaxis to prevent infective endocarditis in high-risk patients and other bacteraemia-induced infections in individuals with orthopaedic prostheses, impaired host defences and on haemodialysis is probably justified prior to dental treatment. Yet the issue of risk-benefit needs to be properly addressed. In some situations antibiotic prophylaxis may, potentially, be more harmful to the patient than the infection that might be prevented. With antibiotic prophylaxis there is no certainty that it will work in any specific situation. The general impression that dentist-induced bacteraemias are responsible for the vast majority of infective endocarditis cases is erroneous, for these bacteraemias may cause as little as 4 per cent or less of all infective endocarditis. A minor role for dentist-induced bacteraemias in other infections is also likely.