Investigation of oral malodor prevention by dentifrices as measured by VSC reduction

Abstract

The oral malodor reduction efficacy of dentifrices containing stannous fluoride (SnF2) or zinc plus arginine (Zn/Arg) was evaluated using a halimeter to measure volatile sulfur compounds (VSCs) in two randomized, controlled, single-blind, cross-over pilot clinical trials. Study 1 (N = 16) had five 1100 ppm F dentifrices and five treatment periods: negative control (NC): 0.243% sodium fluoride (NaF); SnF2 A: 0.454% SnF2 + pyrophosphate; SnF2 B: 0.454% SnF2 + sodium hexametaphosphate; SnF2 C: 0.454% SnF2 + citrate; and SnF2 D: experimental 0.454% SnF2 with increased bioavailable Sn. Study 2 (N = 16) had four 1450 ppm F dentifrices and four treatment periods: NC: 0.1% NaF + 0.76% sodium monofluorophosphate; Zn/Arg: NaF + zinc + arginine; SnF2 E: 0.454% SnF2 + 0.078% NaF + sodium hexametaphosphate; SnF2 F: 0.454% SnF2 + 0.078% NaF + citrate. Each period took 96 h; baseline (day 0) morning to day 4 morning. Subjects brushed 2x/day with the treatment dentifrice. VSC levels were measured in the morning, prior to morning brushing, on days 0 and 4. Changes in VSC scores from day 0 to day 4 were assessed using a mixed-model analysis of covariance for cross-over studies. In study 1, SnF2 dentifrices B, C and D showed statistically significant reductions (31.3%, 24.8%, 34%, respectively) in VSC scores versus baseline (p < 0.001); the benefits of these treatments versus NC and SnF2 dentifrice A were statistically significant (p ⩽ 0.001). In study 2, SnF2 dentifrices E and F showed statistically significant reductions (31.2%, 22.1%, respectively) in VSC scores versus baseline (p ⩽ 0.010); the benefits of these treatments versus NC and the Zn/Arg dentifrice were statistically significant (p ⩽ 0.035). The Zn/Arg dentifrice showed a significant increase of 35.2% (p < 0.001) in VSC scores versus baseline. These studies demonstrated that SnF2 dentifrices can provide significant oral malodor reductions, but the benefit is formulation dependent. The presence of SnF2 is not sufficient to ensure efficacy. The Zn/Arg dentifrice increased VSC levels, indicating greater malodor. Clinical Trial Numbers: 20190429 and 20191028