OBJECTIVE To evaluate the 8-week dentin hypersensitivity efficacy of three toothpastes: (1) a dentifrice containing 0.3% triclosan, 2.0% PVM/MA copolymer, 0.243% sodium fluoride and specially-designed silica (Test Dentifrice 1); (2) a commercially-available dentifrice containing 0.454% stannous fluoride in a silica base with sodium hexametaphosphate and zinc lactate (Test Dentifrice 2); and (3) a commercially-available non-sensitive dentifrice containing 0.243% sodium fluoride in a silica base (Negative Control Dentifrice). METHODS For this 8-week randomized controlled clinical study, qualifying subjects had to have at least two hypersensitive teeth with a tactile hypersensitivity score (Yeaple Probe) between 10 and 50 grams of force, and air blast hypersensitivity score of 2 or 3 (Schiff Cold Air Sensitivity Scale). Subjects brushed twice daily for 1 minute, using the assigned toothpaste and toothbrush. Dentin hypersensitivity assessments, as well as examinations of oral hard and soft tissues, were conducted at the baseline examination and after 4 and 8 weeks of brushing. RESULTS 118 subjects complied with the protocol, and completed the 8-week study. At baseline, the mean tactile sensitivity scores for toothpastes (1), (2) and (3) were 13.6, 14.1 and 13.1; at 4 weeks 28.75, 20.13, and 20.00; and after 8 weeks 33.1, 24.0 and 20.5, respectively. The mean air blast scores for toothpastes (1), (2), and (3) at baseline were 2.5, 2.5, and 2.4; at 4 weeks 1.25, 1.50 and 1.85; and after 8 weeks 0.99, 1.36 and 1.5, respectively. At all time points after the baseline examination, for both tactile and air blast sensitivity scores, the differences between Test Dentifrice 1 and the Negative Control Dentifrice were statistically significant (P < 0.05). The differences between Test Dentifrice 1 and Test Dentifrice 2 were statistically significant (P < 0.05) at 4 and 8 weeks after baseline examination for tactile sensitivity scores and at 8 weeks after baseline examination for air blast sensitivity scores.