The clinical discipline we call Periodontology has come a long way. Concepts and procedures for the treatment of periodontal disease are scientifically based, well-defined and generally adopted and applied by clinicians. Rational measures to prevent these diseases are available and widely practiced in industrialized societies. The goal of virtually eliminating periodontal disease as a public health problem seems not only feasible but probable summarize the major accomplishments of periodontal research over the past three and one-half decades, and to identify and discuss some of the more important remaining critical issues that still need to be addressed.