Clinical trials and the evaluation of new periodontitis therapies.

A number of new periodontitis therapies have recently emerged for either inhibiting disease progression or regenerating lost tissues. As basic research continues to define specific bacteria and host response mechanisms involved in periodontitis, the development of new treatment strategies will continue to expand. This surge in biotechnology along with a tightening of federal regulations has prompted intense interest in clinical trials for testing new periodontitis therapies. A clinical trial is a scientific experiment involving human subjects in which treatment is initiated specifically for evaluation. The overall goal of any clinical trial is to minimize bias and variability. Studying periodontitis in clinical trials presents three problems related to this goal. Periodontitis is a heterogeneous disease grouping, the course of disease is often irregular, and conventional assessment instruments are associated with high error thresholds. Several methods can be used to minimize bias and variability when planning periodontitis trials. These include experimental design selection; inclusion and exclusion criteria; randomization of treatment and blinding; and standardization of treatment, follow-up, and assessment procedures. In addition, recently developed automated periodontal probes and computer-assisted radiography show promise in accurately detecting subtle changes in periodontal support. With improved planning, conduct, and reporting of periodontal clinical trials, investigators can facilitate the transfer of information to clinicians, who can decide on the utility of these new therapies for their periodontitis patients.