Evidence based dentistry: design architecture.

It is important for clinicians to understand the type of clinical studies that appear in the literature and the inherent strengths and limitations of each study. The three possible alternative explanations, chance, bias, and confounding, must be considered for any research study. Thus, it is important to evaluate research studies critically in light of this discussion and not simply to summarize the findings. Finally, conclusions about causality can only be made on the body of evidence, not on any single study.