The purpose of this study is to present and discuss statistical issues as they arise in the design and analysis of gingivitis clinical trials demonstrating either superiority or equivalence. The problems of designing and interpreting data that are obtained from an equivalence trial are being investigated. There are a variety of statistical issues that are important when conducting studies in which no bona fide control or placebo group is included. Their implications for gingivitis studies will be the focus of this study.
