Aging is the physiologic change that occurs over time. In humans, this change occurs at different rates and are related to lifestyle, environment and genetics. It can be challenging to differentiate normal aging from disease. In the oral cavity, with increasing age the teeth demonstrate wearing of the enamel, chipping and fracture lines, and a darker color. The pulp chamber and canals are reduced in size as a result of the deposition of secondary dentin. Coronal or root caries, however, represent disease. A limited amount of periodontal attachment loss occurs in association with aging, usually manifesting as recession on the buccal surface of teeth. Severe periodontitis occurs in 10.5–12% of the population, with the peak incidence being observed at 35–40 years of age. Changes to the mucosal tissue that occur with age include reduced wound-healing capacity. However, environmental factors, such as smoking, dramatically increase the risk of mucosal pathology. Reduced salivary gland function is often seen in association with medication usage, as well as with disorders such as diabetes mellitus. Both medication use and chronic disorders are more common in older adults. Masticatory function is of particular importance for older adults. Maintenance of a nutritionally complete diet is important for avoiding sarcopenia and the frailty syndrome. Successful oral aging is associated with adequate function and comfort. A reduced, but functional, dentition of 20 teeth in occlusion has been proposed as a measure of successful oral aging. Healthy oral aging is important to healthy aging from both biological and social perspectives.