At present, the diagnosis of periodontal disease requires a clinical evaluation of the patient including visual findings, the use of the periodontal probe, and radiographs. No test is available to evaluate disease activity. In specific cases, adjunctive procedures may also be useful. The identification of pathogenic microorganisms may aid in evaluating the periodontal status of special patients. However, these are not required for an adequate diagnosis of the common adult form of chronic periodontitis.