The laboratory for Cellular Research is currently involved with a wide variety of histologic, autoradiographic and electron microscopic experiments integrated into the study of parodontal tissue changes in normal and traumatized short-lived mice concomitant with aging. Histologic studies involve evaluation of tissue age changes, whereas, autoradiographic studies involve the use of H3-thymidine, H3-proline, H3-carbohydrates, and H3-uridine to delineate the cellular kinetics, proliferative potentials, growth, remodeling and repair activities of the various cell compartments with increasing age. The distal effects of injury, the cell kinetics of rewounding and gingival fiber reformation are also under study in aging animals. Electron microscopic studies presently encompass a survey of the effects of aging on parodontal tissues including the gingiva, periodontium alveolar bone and cementum. The entire gerontologic research program is designed to furnish significant information at different levels regarding the effects of aging on the functional maintenance, and reparative potentials of the numerous cell compartments which comprise the dental tissues.