Design of studies or clinical trials to evaluate the effectiveness of agents or procedures for the prevention, or treatment, of loss of the periodontium.

The purpose of this paper is to evaluate the available methods for recording and assessing loss or gain of the periodontium following preventive and therapeutic procedures. Measurements from the cementum-enamci junction to the alveolar crest also can he obtained with soft tissue penetration of a probe after the use of anesthetics, or with either probe, or calipers, during periodontal surgery after exposure of the alveolar crest. An obvious way of assessing loss of periodontal support is by count of teeth lost from periodontal disease with or without various types of preventive and therapeutic procedures.