Duration of effect of the mouthwash CB12 for the treatment of intra-oral halitosis: a double-blind, randomised, controlled trial.

Halitosis occurs in approximately 30% of the adult population and has a negative social and psychological impact on affected individuals. Mouthwashes may be used to prevent unpleasant odour, with long-duration of effect being a desirable attribute. The aim of this study was to assess the long-term efficacy of CB12 (a mixture of 0.3% zinc acetate and 0.025% chlorhexidine) for the treatment of intra-oral halitosis. Thirty-four subjects with confirmed intra-oral halitosis were randomized into a double-blind, controlled, cross-over study to one of 2 groups; (i) CB12-water-water or (ii) water-CB12-CB12. Each group comprised 3 treatments, each given evening and morning (12 h apart) on consecutive study days, with a 5 d washout between treatments. Intra-oral halitosis was assessed objectively by measuring concentrations of hydrogen sulphide, methyl mercaptan, dimethyl sulphide and total volatile sulphur compound (VSC) concentrations and subjectively using organoleptic score (OLS). These were measured at baseline, 12 h after the evening rinse (i.e. 12 h overnight assessment) and 12 h after the daytime rinse (i.e. 12 h day time assessment). CB12 significantly reduced mean hydrogen sulphide, methyl mercaptan, dimethyl sulphide and VSC concentrations, with a duration of effect lasting 12 h, whether assessed overnight (all p  ⩽  0.0003 versus water) or during the day (all p  ⩽  0.0007 versus water). CB12's effect on OLS was also evident for 12 h overnight (p  =  0.0043). CB12 was well-tolerated. In conclusion, CB12 showed a clear and durable effect on intra-oral halitosis which lasted at least 12 h, both during the day and overnight, with consistent effect on both objective and subjective variables.