The objective of this 6-month, double-blind clinical study, conducted following the American Dental Association guidelines, was to investigate the efficacy of Colgate Optimized Stannous Fluoride (COSF) dentifrice for the control of supragingival dental plaque and gingivitis. This dentifrice contains 0.454% stannous fluoride, stannous chloride, polyphosphate, and citrate in a silica base. At the 3- and 6-month study examinations, the COSF dentifrice group exhibited statistically significant reductions in both plaque and gingivitis compared to the control dentifrice group. At the 6-month examination, the magnitude of these percent reductions exceeded 20% for all 4 parameters measured. Thus, the results of this study support the conclusion that the COSF dentifrice is efficacious for the control of supragingival plaque and gingivitis.