Chronic inflammation is a prominent feature of aging and of common age-related diseases, including atherosclerosis, cancer and periodontitis. This volume examines modifiable risk factors for periodontitis and other chronic inflammatory diseases. Oral bacterial communities and viral infections, particularly with cytomegalovirus and other herpesviruses, elicit distinct immune responses and are central in the initiation of periodontal diseases. Risk of disease is dynamic and changes in response to complex interactions of genetic, environmental and stochastic factors over the lifespan. Many modifiable risk factors, such as smoking and excess caloric intake, contribute to increases in systemic markers of inflammation and can modify gene regulation through a variety of biologic mechanisms (e.g. epigenetic modifications). Periodontitis and other common chronic inflammatory diseases share multiple modifiable risk factors, such as tobacco smoking, psychological stress and depression, alcohol consumption, obesity, diabetes, metabolic syndrome and osteoporosis. Interventions that target modifiable risk factors have the potential to improve risk profiles for periodontitis as well as for other common chronic diseases.