IE, although an infrequent event, remains a serious and frequently lethal complication in patients at risk. Oral microorganisms undoubtedly play a significant role in the development of IE in such patients. For example, in a retrospective review of prosthetic cardiac valve candidates (156) at the Cleveland Clinic Foundation, 15% were found to have at least one abscessed tooth, whereas approximately 17% were found to have severe (class IV) periodontal disease.⁹⁵³ Cardiac defects in conjunction with bacteremias from such dental pathoses clearly elevate the risk, although a small but increasing number of noncardiac conditions and behavioral patterns seem also to be able to induce susceptibility. Whether dental or other medical procedures are truly direct inducers of IE, however, remains to be proven and in all probability are only minor contributors overall. Despite its ubiquitous use, antibiotic prophylaxis has not been proven in human clinical trials, and its underlying rationale is arbitrary and questionable at best; nevertheless, its efficacy in animal models has led to the current human protocols. A more profitable strategy, and certainly an adjunctive one, should be to direct one’s efforts at eliminating oral pathology and educating and motivating patients at risk toward meticulous oral hygiene—an exhortation published many years before the advent of antibiotics and still undoubtedly the best recommendation today.