Accordingly, it is not clear which dental procedures are more or less likely to cause a transient bacteremia or result in a greater magnitude of bacteremia than that which results from routine daily activities such as chewing food, tooth brushing, or flossing. In patients with underlying cardiac conditions, lifelong antibiotic therapy is not recommended to prevent IE that might result from bacteremias associated with routine daily activities.5 In patients with dental disease, the focus on the frequency of bacteremia associated with a specific dental procedure and the AHA guidelines for prevention of IE have resulted in an overemphasis on antibiotic prophylaxis and an underemphasis on maintenance of good oral hygiene and access to routine dental care, which are likely more important in reducing the lifetime risk of IE than the administration of antibiotic prophylaxis for a dental procedure. However, no observational or controlled studies support this contention. Impact of Antibiotic Therapy on Bacteremia From a Dental Procedure The ability of antibiotic therapy to prevent or reduce the frequency, magnitude, or duration of bacteremia associated with a dental procedure is controversial.24,74 Some studies reported that antibiotics administered before a dental proce- dure reduced the frequency, nature, and/or duration of bac- teremia,53,75,76 whereas others did not.24,66,77,78 Recent studies suggest that amoxicillin therapy has a statistically significant impact on reducing the incidence, nature, and duration of bacteremia from dental procedures, but it does not eliminate bacteremia.52,53,76 However, no data show that such a reduc- tion as a result of amoxicillin therapy reduces the risk of or prevents IE. Hall et al78 reported that neither penicillin V nor amoxicillin therapy was effective in reducing the frequency of bacteremia compared with untreated control subjects. 