The Modified Gingival Margin Plaque Index: a predictable clinical method

Abstract

Objective: This investigation was designed to determine whether the Modified Gingival Margin Plaque Index (MGMPI) method could consistently detect a significant statistical difference between two control commercial products for antiplaque efficacy.

Methods: The data from 28 studies, where the MGMPI was used on Colgate Total, a well-documented, antiplaque dentifrice versus Colgate Cavity Protection, a regular fluoride dentifrice, were analyzed. The differences between the baseline and a 24-hour plaque scoring were used.

Results: The analysis demonstrated that the delta score from baseline to the 24-hour scoring was consistently lower for the Colgate Total dentifrice. This difference was statistically significant in 23 of the 28 studies, yielding an 82% probability of success rate. The subject numbers in the studies ranged from 9 to 19, and impacted the statistical findings.

Conclusion: The power of a study to detect significant statistical differences is dependent upon the number of subjects in the study or the data sample size. The MGMPI was found to give consistent and predictable data for clinical trials, with the additional benefit of convenience for the examiner and for the subjects.