Book excerpt: ​This book provides a wide-ranging update on the associations between oral infections and general health. Detailed consideration is given to the underlying mechanisms or pathways linking oral infections to general health, including metastatic spread of infection from the oral cavity as a result of transient bacteremia, metastatic injury from the effects of circulating oral microbial toxins, and metastatic inflammation caused by immunological dysfunction induced by oral microorganisms. The book also reviews the complex structure and development of oral biofilms in health and disease, and the molecular tools that are currently available for their analysis. The advantages and limitations of such techniques, as well as their impact on the future of diagnostics, prevention and patient management, are discussed.