The use of the Modified Gingival Margin Plaque Index (MGMPI) method to investigate the inhibitory effect of various toothpastes on dental plaque formation

Abstract

Objective: Colgate Total (CTT) is the only FDA-approved toothpaste for antiplaque and antigingivitis benefits. The objective of this study was to compare the impact of Colgate Total Pharma (CTP), a new variant of Colgate Total, with Colgate Regular Toothpaste (CRT) on plaque formation over a 24-hour period following a single use of the dentifrice.

Methods: CTP and CRT were the two test products. CRT was used for a washout product as well. Fifteen male/female subjects who met the inclusion/exclusion criteria were included into this single-blind (preliminary phase) and double-blind (randomized phase) crossover study. Ethical approval and written informed consent were obtained. Preliminary phase: After a one-week washout with CRT, subjects brushed in the dental clinic with CRT before a one-minute use of a test dentifrice. A baseline Modified Gingival Margin Plaque Index (MGMPI) score was calculated. Subjects refrained from oral hygiene for 24 hours, and returned to the clinic for their 24-hour MGMPI score. Subjects entered the second washout phase to repeat as per the crossover design. The above procedures were conducted three times by three independent examiners. Randomized phase: Subjects were randomized to the groups according to a computer-generated randomization schedule. The procedure was carried out as in the preliminary phase, except the washout period between the two products was at least one week and the products (CTP or CRT) were used in a randomized double-blind manner. Plaque scores were recorded as above.

Results: CTP provided a significant (p = 0.01) antiplaque effect versus CRT. The results are consistent with previously reported data for CTT. All three examiners demonstrated a strong correlation for this clinical study utilizing the MGMPI methodology.

Conclusion: This clinical investigation examined the efficacy of a new variant of a commercial dentifrice, historically shown to provide antiplaque and antigingivitis efficacy. It is important to confirm the continued efficacy of new products to consumers and to the profession. Additionally, this clinical trial demonstrated the usefulness of the clinical methodology with respect to consistency in results by three independent clinical examiners. Because this methodology is often employed to document antiplaque benefits of new and existing technologies, it is important to periodically evaluate and confirm its reliability and reproducibility.