A total of one hundred fifty three healthy male and female adults were entered into a six month, double-blind clinical study designed to evaluate the effect of a dentifrice containing 0.3% triclosan and 2.0% PVM/MA copolymer in a 0.243% sodium fluoride/silica base, relative to a 0.243% sodium fluoride silica base control dentifrice on supragingival plaque accumulation and gingivitis. Plaque and gingivitis were scored after 3 and 6 months' use of the assigned dentifrice. At the end of the study, the dentifrice containing triclosan/copolymer demonstrated an average reduction, relative to the control dentifrice of 16.1% in plaque accumulation and 24.3% in gingivitis. Both were statistically significant(P < 0.001). It was concluded that the twice-daily use of the triclosan/copolymer containing dentifrice resulted in a significant reduction in plaque formation and a significant improvement in gingival health. No side-effects were observed.