A total of 108 adult male and female subjects completed a 7-month, double-blind clinical study designed to compare the effect of a dentifrice containing 0.3% triclosan and 2% of a copolymer of methoxyethylene and maleic acid on plaque formation and gingivitis, as compared to a placebo dentifrice. The subjects were stratified into two balanced groups according to baseline plaque and baseline gingivitis scores. They then received an oral prophylaxis and were assigned to the use of either a placebo dentifrice or the triclosan/copolymer dentifrice for the next 7 months. After this time, the dentifrice containing triclosan/copolymer provided a 58.96% statistically significant (99% level of confidence) reduction in plaque [corrected], as compared to the placebo dentifrice. Further, after 7-months' use, the dentifrice containing triclosan/copolymer also provided a 30.17% statistically significant (99% level of confidence) reduction in gingivitis as compared to the placebo dentifrice. The results after 7 months also indicated that the dentifrice containing triclosan/copolymer provided a 97.74% statistically significant (99% level of confidence) reduction in the supragingival plaque deposits on those tooth surfaces with the greatest amount of plaque formation, when compared to the placebo dentifrice. The dentifrice containing triclosan/copolymer also provided 87.56% less sites with the most severe amount of gingival disease, as compared to the placebo dentifrice. This decrease in diseased gingival sites was statistically significant at the 99% level of confidence. It was concluded that the twice daily use of a dentifrice containing 0.3% triclosan and 2% of a copolymer reduces supragingival plaque deposit formation and gingivitis to a highly significant degree, without any extrinsic stains observed.